Momentus Inc. (MNTS) registers $200M shelf for stock, debt and warrants

Rhea-AI Filing Summary

Momentus Inc. is registering up to $200,000,000 of securities on a shelf prospectus. This shelf permits Momentus to offer, from time to time, common stock, preferred stock, debt securities, warrants or units in one or more offerings with specific terms set in prospectus supplements.

The prospectus discloses recent financings: a January 2026 private placement that generated approximately $5.0 million gross ($4.58 million net) and an April 2026 private placement that generated approximately $5.0 million gross ($4.58 million net). The company reports 10,547,553 shares of common stock issued and outstanding as of May 21, 2026 and describes use of shelf proceeds for working capital and general corporate purposes.

Key Figures

Shelf capacity: $200,000,000 Shares outstanding: 10,547,553 shares Non-affiliate market value: $79.8 million +4 more

7 metrics

Shelf capacity $200,000,000 maximum aggregate offering amount under this prospectus

Shares outstanding 10,547,553 shares Common Stock issued and outstanding as of May 21, 2026

Non-affiliate market value $79.8 million Aggregate market value of common stock held by non-affiliates (based on 10,457,184 shares at $7.63)

January 2026 gross proceeds $5.0 million aggregate gross proceeds from the January 2026 private placement

January 2026 net proceeds $4.58 million net proceeds after placement agent fees from the January 2026 private placement

April 2026 shares sold 450,000 shares April 2026 private placement shares purchased at $3.75 each

April 2026 pre-funded warrants 883,334 warrants pre-funded warrants issued April 14, 2026 (price $3.74999)

Key Terms

Tape Spring Solar Array (TASSA), Microwave Electrothermal Thruster (MET), Orbital Service Vehicle (OSV), Rendezvous and Proximity Operations (RPO), +1 more

5 terms

Tape Spring Solar Array (TASSA) technical

"We are developing an innovative Tape Spring Solar Array (“TASSA”)"

Microwave Electrothermal Thruster (MET) technical

"Our Microwave Electrothermal Thruster (“MET”) that uses water as a propellant"

Orbital Service Vehicle (OSV) technical

"We plan to provide these services with Orbital Service Vehicles (“OSVs”)"

Rendezvous and Proximity Operations (RPO) technical

"first of these technologies is related to Rendezvous and Proximity Operations (“RPO”)"

Pre‑funded warrant financial

"pre-funded warrants to purchase up to 925,926 shares of Common Stock"

Offering Details

base_shelf_indeterminate

Offering

Offering Type base_shelf_indeterminate

Use of Proceeds working capital and general corporate purposes

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As filed with the Securities and Exchange Commission on May 26, 2026

Registration Statement No. 333-   

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

MOMENTUS INC.

(Exact name of registrant as specified in its charter)

Delaware			3714			84-1905538
(State or other jurisdiction of incorporation or organization)			(Primary Standard Industrial Classification Code Number)			(I.R.S. Employer Identification No.)

1762 Automation Parkway

San Jose, CA 95131

(650) 564-7820

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

John C. Rood

Chief Executive Officer

1762 Automation Parkway

San Jose, California 95131

Telephone: (650) 564-7820

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Stephen C. Hinton, Esq.

Bradley Arant Boult Cummings LLP

1221 Broadway

Nashville, Tennessee 37203

Telephone: (615) 252-3585

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement, as determined by market conditions.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer			☐			Accelerated filer			☐
Non-accelerated filer			☒			Smaller reporting company			☒
						Emerging growth company			☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided to Section 7(a)(2)(B) of the Securities Act. ☐

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until this registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

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The information contained in this prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to Completion, Dated May 26, 2026

PROSPECTUS

$200,000,000

MOMENTUS INC.

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may, from time to time, offer and sell up to $200,000,000 of any combination of our Class A common stock, par value $0.00001 (the “common stock” or “Common Stock”), preferred stock, par value $0.00001 (the “preferred stock”), debt securities, warrants or units described in this prospectus, either individually or in combination with other securities, at prices and on terms described in one or more supplements to this prospectus. We may also offer common stock or preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock, or debt securities upon the exercise of warrants.

This prospectus provides you with a general description of the securities that we may offer. Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference, before buying any of the securities being offered.

Securities may be sold by us to or through underwriters or dealers, directly to purchasers or through agents designated from time to time. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

Our common stock is listed on The Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “MNTS.” On May 22, 2026, the last reported sale price of our common stock on Nasdaq was $7.38 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on any securities market or other exchange of the specific security covered by such prospectus supplement.

As of the date of this prospectus, the aggregate market value of our outstanding common stock held by non-affiliates is approximately $79.8 million, which is calculated based on 10,457,184 shares of our outstanding common stock held by non-affiliates and a price of $7.63 per share, the closing price of our common stock on April 16, 2026, which is the highest closing price of our common stock on Nasdaq within the prior 60 days of this prospectus.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” beginning on page 8 of this prospectus and contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the other documents that are incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is    , 2026.

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			Page
About this Prospectus			ii
Prospectus Summary			1
Risk Factors			8
Forward-Looking Statements			9
Use of Proceeds			10
Description of Capital Stock			11
Description of Debt Securities			16
Description of Warrants			22
Description of Units			24
Legal Ownership of Securities			25
Plan of Distribution			28
Legal Matters			30
Experts			30
Where You Can Find More Information			30
Incorporation of Certain Information by Reference			31

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration statement, we may sell from time to time in one or more offerings up to a total dollar amount of $200,000,000 of shares of common stock, preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or as units in combination with other securities as described in this prospectus. Each time we sell any type or series of securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents we have incorporated by reference into this prospectus. To the extent that any statement that we make in a prospectus supplement is inconsistent with statements made in this prospectus, the statements made in this prospectus will be deemed modified or superseded by those made in a prospectus supplement. You should carefully read both this prospectus and the applicable prospectus supplement and any related free writing prospectus, together with the additional information described under “Where You Can Find More Information,” before buying any of the securities being offered.

THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE A SALE OF SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT

Neither we, nor any agent, underwriter or dealer has authorized any person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus prepared by or on behalf of us or to which we have referred you. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus, any applicable supplement to this prospectus or any related free writing prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor does this prospectus, any applicable supplement to this prospectus or any related free writing prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction.

You should not assume that the information contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the document incorporated by reference, even though this prospectus, any applicable prospectus supplement or any related free writing prospectus is delivered, or securities are sold, on a later date.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.”

Except as otherwise indicated herein or as the context otherwise requires, references in this prospectus to “Momentus,” “the Company,” “we,” “us,” “our” and similar references refer to Momentus Inc., an entity incorporated under the laws of the State of Delaware, and where appropriate our consolidated subsidiaries.

This prospectus and the information incorporated herein by reference include trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus, any applicable prospectus supplement or any related free writing prospectus are the property of their respective owners.

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PROSPECTUS SUMMARY

The following summary highlights information contained elsewhere in this prospectus or incorporated by reference herein and does not contain all the information that may be important to purchasers of our securities. Prospective purchasers of our securities should carefully read the entire prospectus, the applicable prospectus supplement and any related free writing prospectus, including the risks of investing in our securities discussed under the heading “Risk Factors” contained in this prospectus, the applicable prospectus supplement and any related free writing prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus. Prospective purchasers of our securities should also carefully read the information incorporated by reference into this prospectus, including our financial statements, and the exhibits to the registration statement of which this prospectus is a part.

The Company

Momentus is a U.S. commercial space company that offers satellites, satellite buses, and other satellite components, transportation and infrastructure services, including hosted payloads and other in-orbit services to help enable the commercialization of space. Satellite operators are our principal customers and target customers. Momentus offers satellites and satellite buses and technology designed to meet the specific needs of government and commercial customers.

We provide or plan to provide satellites, satellite buses, solar arrays, and other satellite components. Our satellites and satellite technologies offer competitive advantages to customers such as greater payload capability, significant on-orbit power, flexibility of design and the ability to accommodate a range of sensors, communications equipment, and other space instruments, low cost, and speed of delivery.

We are developing an innovative Tape Spring Solar Array (“TASSA”) that has the potential to produce power at substantially lower cost than competing solar arrays. TASSA also has important advantages in its ability to be deployed and retracted to protect the array from in-space collisions with debris and to easily maneuver the satellite to different locations or adjust its characteristics.

Over the past several years, Momentus has developed other innovative technologies, such as our Microwave Electrothermal Thruster (“MET”) that uses water as a propellant, designed to efficiently accomplish missions such as transportation of customer payloads and small satellites to custom orbits. The MET’s water propellant is safe, environmentally-friendly, and easy to transport and handle, in contrast to the highly-toxic and difficult to handle propellants commonly used in the space industry. The MET has high specific impulse, or ISP, which is a measure of efficiency, making it well-suited for transportation missions with significantly higher thrust than missions more suitable for low thrust electric propulsion. The MET has been successfully demonstrated on orbit and we have matured this technology to Technology Readiness Level 9, the highest level, with hundreds of successful firings in space during our missions. We have designed our satellite buses and Orbital Service Vehicles to use this innovative technology, while also implementing a modular design that enables Momentus to incorporate high-thrust chemical thrusters or electric thrusters instead of the MET for missions with different requirements.

We provide or plan to provide services, including “last mile” satellite transportation, payload-hosting, on-orbit satellite refueling, on-orbit inspection, on-orbit satellite maintenance, de-orbiting, debris removal, and other satellite-to-satellite service offerings. We believe our planned service offerings will increase deployment options for satellite operators and lower their operating costs relative to traditional approaches while also minimizing environmental impact when utilizing our MET with water as a propellant.

We plan to provide these services with Orbital Service Vehicles (“OSVs”) that we design and manufacture. While we plan to eventually operate a family of progressively larger and more capable OSVs, we are currently focused on Vigoride, which was originally designed to operate in low-Earth orbit (“LEO”), but is undergoing enhancements designed to allow it to operate in Geostationary-Earth Orbit (“GEO”), Lunar, and Deep Space orbits.

We believe that Vigoride has the ability to deliver fast, versatile, and cost-effective transportation and infrastructure services to our customers. We conducted our inaugural test and demonstration mission with Vigoride in 2022. Momentus has launched four missions to date, deployed 17 customer satellites, and provided hosted payload services. Three of these missions involved operation of the Vigoride OSV in orbit. During these three Vigoride missions, the system and technology were tested repeatedly. Improvements based on lessons learned during these missions were rapidly incorporated. As a result of these three missions, the Vigoride OSV has been successfully demonstrated in space and accumulated significant flight heritage.

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Our transportation service offering focuses on delivering our customers’ satellites to precision orbits. To accomplish this, we partner with leading launch service providers, such as SpaceX, to “ride share” our customer’s satellites from Earth to space on a midsized or large rocket. Customer satellites can also be carried aboard small launch vehicles for dedicated missions.

Our OSVs would then provide “last mile” transportation services from the rocket’s drop-off orbit to a custom orbit of the satellite operator’s choosing. We believe this “hub-and-spoke” model has the potential to expand our customers’ deployment options relative to what they would be able to achieve with ride share launch alone, while reducing their costs relative to what they could achieve with a dedicated small launch vehicle. Our OSVs are currently expendable, meaning they are used to perform services before they de-orbit themselves upon completion of their mission. However, our goal is to eventually make our OSVs reusable, or capable of remaining in space to conduct follow-on missions, which has the potential to lower our cost of delivering services to our customers. To achieve reusability, we need to develop additional technologies that will allow our vehicles to locate and navigate to customer satellites in space, physically connect to them, and perform a variety of robotic operations including fluid transfer. The first of these technologies is related to Rendezvous and Proximity Operations (“RPO”) which is the ability for the OSV to locate and maneuver to another object in space.

In 2025, the U.S. Air Force Research Labs SpaceWERX organization—which is the innovation arm of the U.S. Space Force—awarded Momentus a Direct to Phase II Small Business Innovation Research (“SBIR”) contract. The award supports the in-space flight demonstration of a novel, low-cost multi-spectral sensor suite for RPO, scheduled for 2026.

We are also offering variants of our Vigoride OSV to government and commercial customers as a traditional bus manufacturer and satellite prime contractor. Vigoride, and its variants, M-500 and M-1000, are being offered to support missions such as communication, sensing and tracking of missiles, positioning, navigation, and timing (“PNT”) as well as payload technology demonstrations.

Momentus offers or plans to offer production and operation of small satellites to meet a range of defense, government, and commercial needs such as communications, tracking of missiles, remote sensing, and space domain awareness. There is a growing need for such capabilities for defense, government, and commercial customers.

Momentus is offering high-volume production of buses, based on Vigoride’s technologies, for hosted payloads by integrating customer’s unique payloads for a variety of missions and for customer-owned satellites for use in constellations. A hosted payload is a module attached to a satellite that can be operated independently from the main spacecraft but which shares the satellite’s power supply and communications equipment. Hosted payloads are often used by commercial and government customers seeking to operate or test a capability for uses such as communications and sensing in orbit without having to pay the cost of building and launching an entire satellite. Using a hosted payload on a commercial satellite can reduce both the expense and time required to get communications and other technologies into space.

Our Vigoride OSVs are intended to provide safe, affordable, reliable, and regular in-space services to our customers, including space transportation, payload hosting, and in-orbit servicing. We designed our Vigoride vehicle to deliver small customer payloads anywhere in LEO. However, we also plan to design and produce larger vehicles and satellite buses to carry larger payloads to more distant orbits such as GEO.

We currently plan to offer the following infrastructure services to the space economy:

• Satellites and Constellation Bus: Momentus offers or plans to offer production and operation of small satellites to meet a range of defense, government, and commercial needs such as communications, tracking of missiles, remote sensing, and space domain awareness. Technologies used to support the Hosted Payload market are directly applicable to offering customer-owned satellites for use in constellations.

• Satellite Technologies: Momentus is developing and plans to offer satellite technologies such as our Tape Spring Solar Array, 3D printed propulsion tanks, and other components used on the Vigoride OSV. These technologies and components have been flown in space, or are scheduled to be flown in space, and offer important competitive advantages such as lower cost and flexibility to meet the needs of owners and operators of satellites.

• Space Transportation: Momentus offers a transportation service to deliver customers’ satellites to precision orbits. Under this model, our customers would deliver their payload to us a few months prior to launch for integration onto our vehicle. Once we have integrated our customers’ payloads, we would then ship our

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vehicle, holding the customer payload, to the launch site, where it would be integrated onto the launch vehicle. The launch vehicle would then transport our vehicle to the drop-off orbit. After separation from the launch vehicle, our OSV would transport our customers’ payloads to their chosen final orbit.

We believe our transportation service has the potential to expand our customers’ deployment options relative to what they could achieve with ride share launch alone, while reducing their costs relative to what they could achieve with a dedicated small launch vehicle.

• Hosted Payload: There are a broad range of payloads, satellite components, and other space technologies, that customers want to operate, test, or validate in space. During development of a satellite component or other system, testing and validation of performance are important, particularly in the harsh environment of space. In other cases, customers wish to operate technologies such as solar collection and energy transmission systems in space without the expense of developing a full system that includes the satellite bus hosting these instruments. Momentus’ hosted payload service allows customers to operate, test, and validate the performance of the technology or system in space at lower cost and less complexity. Momentus’ service offers the ability to manage the integration and operation of these payloads in space. Additionally, Momentus is able to obtain necessary government licenses and manage the integration of these hosted payloads onto our OSV.

• In-Orbit Servicing: As the number of satellites in space increases, so does their need to be serviced. We are actively developing and testing Momentus’ vehicles to be capable of performing in-orbit servicing. We plan to equip future vehicles with robotic arms and an ability to maneuver in close proximity to other spacecraft and grapple, dock, or berth with them. We believe these capabilities could allow us to offer a suite of different in-orbit services, such as inspection, refueling, life extension, re-positioning, salvage missions, maintenance and repair, and de-orbiting.

• Satellite Bus: Technologies used to support the hosted payload market are directly applicable to offering customer-owned satellite buses for use in constellations. Momentus is offering high-volume production of low-cost buses, based on Vigoride’s technologies, and integrating customers’ unique payloads for a variety of missions ranging from communications to Earth Observation. We introduced variants of Vigoride tailored specifically for constellation applications as M-500 and M-1000 in August 2023.

For a further description of the risks associated with our business, see “Risk Factors.” Investors are cautioned to review the following description of Momentus’ business together with the entirety of this prospectus, including the within-mentioned risk factors.

January 2026 Private Placement

On January 5, 2026, the Company engaged in a private placement pursuant to which the Company agreed with an investor (the “January PIPE Investor”) to sell and issue to such stockholder (i) pre-funded warrants to purchase up to 925,926 shares of Common Stock (the “January 2026 Pre-Funded Warrants”), and (ii) warrants to purchase up to 925,926 shares of Common Stock (the “January 2026 Common Warrants”).

The purchase price of each January 2026 Pre-Funded Warrant equals $5.39999, and the exercise price of each January 2026 Pre-Funded Warrant equals $0.00001 per share. The January 2026 Pre-Funded Warrants are exercisable at any time after their original issuance and will not expire until exercised in full. The January 2026 Common Warrants have an exercise price per share of Common Stock equal to $5.40 per share. The January 2026 Common Warrants will be exercisable immediately following receipt of shareholder approval and will expire five years from the initial exercise date. The exercise price and the number of shares of Common Stock issuable upon exercise of the January 2026 Common Warrants is subject to appropriate adjustments in the event of certain stock dividends and distributions, stock splits, stock combinations, reclassifications or similar events affecting the Common Stock.

In connection with the private placement, on January 5, 2028, the Company entered into a Placement Agency Agreement with the Placement Agent. As part of its compensation for acting as Placement Agent for the private placement, the Company paid the Placement Agent a cash fee of 7.0% of the aggregate gross proceeds and also agreed to issue to the warrants to purchase up to 46,296 shares of Common Stock (the “January 2026 PA Warrants”) at an exercise price of $5.94, which are exercisable on or after July 6, 2026. The January 2026 PA Warrants have a term of five years from January 6, 2026.

The Company received aggregate gross proceeds from the private placement of approximately $5 million, before deducting placement agent commissions and expenses in connection with the private placement, which were paid by the

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Company. After deducting the approximately $0.42 million paid to the Placement Agent pursuant to the Placement Agency Agreement, the Company received approximately $4.58 million in proceeds from the private placement. The Company agreed to use the net proceeds from the private placement for general corporate purposes, which may include repayment of principal on the Company’s indebtedness, capital expenditures, and funding its working capital needs.

Also in connection with the private placement, the Company and the January 2026 PIPE Investor agreed to reduce the exercise price of certain warrants issued to the 2026 PIPE Investor on October 15, 2025 and December 11, 2025 from $13.74 per share to $5.40 per share.

April 2026 Private Placement

On April 14, 2026, the Company engaged in a private placement pursuant to which the Company agreed with an investor (the “April PIPE Investor”) to sell and issue to such stockholder (i) 450,000 shares of Common Stock (the “April 2026 Private Placement Shares”) and (ii) pre-funded warrants to purchase up to 883,334 shares of Common Stock (the “April 2026 Pre-Funded Warrants”).

The purchase price of each April 2026 Private Placement Share equals $3.75. The purchase price of each April 2026 Pre-Funded Warrant equals $3.74999, and the exercise price of each April 2026 Pre-Funded Warrant equals $0.00001 per share. The April 2026 Pre-Funded Warrants are exercisable at any time after their original issuance and will not expire until exercised in full.

In connection with the private placement, on April 14, 2026, the Company entered into a Placement Agency Agreement with the Placement Agent. As part of its compensation for acting as Placement Agent for the private placement, the Company paid the Placement Agent a cash fee of 7.0% of the aggregate gross proceeds and also agreed to issue to the warrants to purchase up to 66,666 shares of Common Stock (the “April 2026 PA Warrants”) at an exercise price of $4.125, which are exercisable on or after October 11, 2026. The April 2026 PA Warrants have a term of five years from April 15, 2026.

The Company received aggregate gross proceeds from the private placement of approximately $5 million, before deducting placement agent commissions and expenses in connection with the private placement, which were paid by the Company. After deducting the approximately $0.42 million paid to the Placement Agent pursuant to the Placement Agency Agreement, the Company received approximately $4.58 million in proceeds from the private placement. The Company agreed to use the net proceeds from the private placement for general corporate purposes, which may include repayment of principal on the Company’s indebtedness, capital expenditures, and funding its working capital needs.

Capital Resources

Our consolidated financial statements are prepared assuming that the Company will continue as a going concern. The going concern basis of presentation assumes that the Company will continue in operation one year after the date the consolidated financial statements are issued and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business. The Company previously disclosed that conditions and events raised substantial doubt regarding its ability to continue as a going concern. Management believes that, as a result of the financings and related transactions completed since December 31, 2025, substantial doubt no longer exists.

Implications of Being a Smaller Reporting Company

As a company with less than $100 million of annual revenue in our most recently completed fiscal year and the market value of our stock held by non-affiliates as of June 30, 2024, was less than $700 million, we qualify as a “smaller reporting company” as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended. A smaller reporting company may take advantage of specified reduced reporting requirements that are otherwise applicable generally to public companies. These reduced reporting requirements include, but are not limited to, reduced disclosure about our executive compensation arrangements and an exemption from the requirements to obtain a non-binding advisory vote on golden parachute arrangements. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock.

Corporate Information

We were incorporated in the State of Delaware in May 2019 as a special purpose acquisition company under the name Stable Road Acquisition Corp. On November 13, 2019, we completed our initial public offering. On August 12, 2021, we consummated a business combination with Momentus Inc. (a separate legal entity from the Company) pursuant to that Agreement and Plan of Merger, dated October 7, 2020. In connection with such business combination, we changed our name from Stable Road Acquisition Corp. to Momentus Inc.

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Our principal executive offices are located at 1762 Automation Parkway, San Jose, California 95131. Our telephone number is (650) 564-7820. Our website address is www.momentus.space. Information contained on our website or connected thereto does not constitute part of, and is not incorporated by reference into, this prospectus or the registration statement of which it forms a part.

Momentus, the Momentus logo and our other registered or common law trademarks, service marks or trade names appearing in this prospectus are the property of Momentus. Other trademarks, service marks and trade names used in this prospectus are the property of their respective owners.

Risks Associated with our Business

Our business is subject to numerous risks, as described under the heading “Risk Factors” contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the documents that are incorporated by reference into this prospectus.

The Securities We May Offer

We may offer shares of our common stock, preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or as units in combination with other securities, with a total value of up to $200,000,000 from time to time under this prospectus at prices and on terms to be determined at the time of any offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

• designation or classification;

• aggregate principal amount or aggregate offering price;

• maturity;

• original issue discount;

• rates and times of payment of interest or dividends;

• redemption, conversion, exercise, exchange or sinking fund terms;

• ranking;

• restrictive covenants;

• voting or other rights;

• conversion or exchange prices or rates and, if applicable, any provisions for changes to or adjustments in the conversion or exchange prices or rates and in the securities or other property receivable upon conversion or exchange; and

• a discussion of material United States federal income tax considerations, if any.

The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in documents we have incorporated by reference. However, no prospectus supplement or free writing prospectus will offer a security that is not registered and described in this prospectus at the time of the effectiveness of the registration statement of which this prospectus is a part.

We may sell the securities directly to investors or to or through agents, underwriters or dealers. We, and our agents, underwriters or dealers reserve the right to accept or reject all or part of any proposed purchase of securities. If we do offer securities to or through agents, underwriters or dealers, we will include in the applicable prospectus supplement:

• the names of those agents, underwriters, or dealers;

• applicable fees, discounts and commissions to be paid to them;

• details regarding over-allotment options, if any; and

• the net proceeds to us.

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The following is a summary of the securities we may offer with this prospectus.

Common Stock

We may issue shares of our common stock from time to time. Each holder of our common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Under our second amended and restated certificate of incorporation, as amended (the “Certificate of Incorporation”) and second amended and restated bylaws (the “Bylaws”), our stockholders do not have cumulative voting rights. Subject to preferences that may be applicable to any then-outstanding preferred stock, holders of common stock are entitled to receive ratably those dividends, if any, as may be declared from time to time by the board of directors out of legally available funds. In the event of our liquidation, dissolution or winding up, holders of common stock are entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then-outstanding shares of preferred stock. Holders of shares of our common stock do not have preemptive, subscription, redemption, or conversion rights and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate in the future.

Preferred Stock

We may issue shares of our preferred stock from time to time, in one or more series. Our board of directors will determine the designations, voting powers, preferences and rights of the preferred stock, as well as the qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, preemptive rights, terms of redemption or repurchase, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of any series. Convertible preferred stock will be convertible into our common stock or exchangeable for other securities. Conversion may be mandatory or at the holder’s option and would be at prescribed conversion rates. If we sell any series of preferred stock under this prospectus, we will fix the designations, voting powers, preferences and rights of such series of preferred stock, as well as the qualifications, limitations or restrictions thereof, in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of any certificate of designation that describes the terms of the series of preferred stock that we are offering before the issuance of the related series of preferred stock.

We urge you to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the series of preferred stock being offered, as well as the complete certificate of designation that contains the terms of the applicable series of preferred stock.

Debt Securities

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. The senior debt securities will rank equally with any other unsecured and unsubordinated debt. The subordinated debt securities will be subordinate and junior in right of payment, to the extent and in the manner described in the instrument governing the debt, to all of our senior indebtedness. Convertible debt securities will be convertible into or exchangeable for our common stock or other securities. Conversion may be mandatory or at your option and would be at prescribed conversion rates.

Any debt securities issued under this prospectus will be issued under one or more documents called indentures, which are contracts between us and a national banking association or other eligible party, as trustee. In this prospectus, we have summarized certain general features of the debt securities. We urge you, however, to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the series of debt securities being offered, as well as the complete indentures that contain the terms of the debt securities. A form of indenture has been filed as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

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Warrants

We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series. We may issue warrants independently or as units in combination with common stock, preferred stock and/or debt securities, and the warrants may be attached to or separate from these securities. In this prospectus, we have summarized certain general features of the warrants.

We urge you, however, to read the applicable prospectus supplement (and any free writing prospectus that we may authorize to be provided to you) related to the series of warrants being offered, as well as any warrant agreements and warrant certificates that contain the terms of the warrants. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants.

Any warrants issued under this prospectus may be evidenced by warrant certificates. Warrants also may be issued under an applicable warrant agreement that we enter into with a warrant agent. We will indicate the name and address of the warrant agent, if applicable, in the prospectus supplement relating to the particular series of warrants being offered.

Units

We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of the unit agent in the applicable prospectus supplement relating to a particular series of units.

In this prospectus, we have summarized certain general features of the units under “Description of Units.” We urge you, however, to read the applicable prospectus supplement (and any related free writing prospectus that we may authorize to be provided to you) related to the series of units being offered, as well as the complete unit agreement that contains the terms of the units. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the specific unit agreement that contains the terms of the particular series of units we are offering, before the issuance of such units.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and discussed under the section entitled “Risk Factors” contained in our most recent Annual Report on Form 10-K, as may be updated by subsequent annual, quarterly and other reports that are incorporated by reference into this prospectus in their entirety. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Forward-Looking Statements.”

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FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference herein, contains, and any applicable prospectus supplement or free writing prospectus including the documents we incorporate by reference therein may contain, forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Exchange Act, including statements regarding our future financial condition, business strategy and plans and objectives of management for future operations. Forward-looking statements include all statements that are not historical facts. In some cases, you can identify forward-looking statements by terminology such as “believe,” “will,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “might,” “approximately,” “expect,” “predict,” “could,” “potentially” or the negative of these terms or other similar expressions. Forward-looking statements include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations.

Discussions containing these forward-looking statements may be found, among other places, in the sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in the documents incorporated by reference herein, including our most recent Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K, as well as any amendments thereto.

These statements relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that could cause our actual results, levels of activity, performance or achievement to differ materially from those expressed or implied by these forward-looking statements. We discuss in greater detail, and incorporate by reference into this prospectus in their entirety, many of these risks and uncertainties under the heading “Risk Factors” contained in the applicable prospectus supplement, in any free writing prospectus we may authorize for use in connection with a specific offering, and in the documents incorporated by reference herein. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. We undertake no obligation to revise or publicly release the results of any revision to these forward-looking statements, except as required by law. Given these risks and uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. All forward-looking statements are qualified in their entirety by this cautionary statement.

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USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds from the sale of the securities offered hereby. Except as described in any prospectus supplement or in any related free writing prospectus that we may authorize to be provided to you, we currently intend to use the net proceeds from the sale of the securities offered by us hereunder primarily for working capital and general corporate purposes. We will set forth in the applicable prospectus supplement or free writing prospectus our intended use for the net proceeds received from the sale of any securities sold pursuant to the prospectus supplement or free writing prospectus.

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DESCRIPTION OF CAPITAL STOCK

The following is a description of the material terms of our capital stock. This is a summary only and does not purport to be complete. It is subject to and qualified in its entirety by reference to our Second Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, each of which are incorporated by reference as an exhibit to the registration statement of which this prospectus forms a part. We encourage you to read our Second Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, and the applicable provisions of the Delaware General Corporation Law (the “DGCL”), for additional information.

Authorized and Outstanding Stock

Pursuant to the terms of our Second Amended and Restated Certificate of Incorporation, as amended, our authorized capital stock consists of:

• 250,000,000 shares of the Common Stock, $0.00001 par value per share; and

• 20,000,000 shares of undesignated Preferred Stock, $0.00001 par value per share (“Preferred Stock”), of which 673,408 shares have been designated as the Series A Convertible Preferred Stock.

As of May 21, 2026, there were 10,547,553 shares of the Common Stock issued and outstanding and no shares of Preferred Stock outstanding.

Common Stock

Voting Power

Holders of Common Stock are entitled to one vote per share on all matters submitted to a vote of stockholders. The holders of Common Stock will generally vote together as a single class on all matters submitted to a vote of stockholders, unless otherwise required by Delaware law or the Second Amended and Restated Certificate of Incorporation, as amended.

The Second Amended and Restated Certificate of Incorporation, as amended, and the Amended and Restated Bylaws, as amended (collectively, our “Organizational Documents”), established a classified board of directors (the “board”) that is divided into three classes with staggered three-year terms. Only the directors in one class will be subject to election by a plurality of the votes cast at each annual meeting of stockholders, with the directors in the other classes continuing for the remainder of their respective three-year terms. The Second Amended and Restated Certificate of Incorporation does not provide for cumulative voting for the election of directors.

Dividend Rights

Subject to preferences that may apply to any shares of Preferred Stock outstanding at the time, the holders of Common Stock are entitled to receive dividends out of funds legally available if the board, in its discretion, determines to issue dividends and then only at the times and in the amounts that the board may determine.

We have not paid any cash dividends on the Common Stock to date and do not intend to pay cash dividends in the foreseeable future. The payment of cash dividends in the future will be dependent upon our revenues and earnings, if any, capital requirements, the terms of any outstanding indebtedness and general financial condition. The payment of any cash dividends will be within the discretion of the board at such time. In addition, the board is not currently contemplating and does not anticipate declaring any stock dividends in the foreseeable future.

No Preemptive or Similar Rights

The holders of the Common Stock are not entitled to preemptive rights and are not subject to conversion (except as noted above), redemption or sinking fund provisions.

Right to Receive Liquidation Distributions

If we become subject to a liquidation, dissolution or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of Common Stock and any participating Preferred Stock outstanding at that time, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights of and the payment of liquidation preferences, if any, on any outstanding shares of Preferred Stock.

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Fully Paid and Non-Assessable

All of the outstanding shares of Common Stock are fully paid and non-assessable.

Preferred Stock

Our board is authorized, subject to limitations prescribed by Delaware law, to issue Preferred Stock in one or more series, to establish from time to time the number of shares to be included in each series, and to fix the designation, vesting, powers, preferences, and rights of the shares of each series and any of its qualifications, limitations, or restrictions, in each case without further vote or action by the stockholders. Our board can also increase or decrease the number of shares of any series of Preferred Stock, but not below the number of shares of that series then outstanding, without any further vote or action by the stockholders.

Our board may authorize the issuance of Preferred Stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of Common Stock. The issuance of Preferred Stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring, or preventing a change in control of the Company and may adversely affect the market price of Common Stock and the voting and other rights of the holders of Common Stock.

We filed the Certificate of Designations, which designated 673,408 shares of our preferred stock as “Series A Convertible Preferred Stock”, none of which are issued and outstanding as of May 21, 2026.

Series A Convertible Preferred Stock

Ranking

With respect to (i) payment of dividends, (ii) distribution of assets, and (iii) all other liquidation, winding up, dissolution, dividend and redemption rights, the Series A Convertible Preferred Stock shall rank pari passu in priority of payment to all Parity Stock (defined below) and senior in priority of payment to all Junior Stock (defined below) in any liquidation, dissolution, winding up or distribution of the Company, and junior to any indebtedness of the Company.

“Junior Stock” means (i) the Common Stock and (ii) any other equity interest of the Company, in each case which by its terms ranks junior to the Series A Convertible Preferred Stock with respect to payment of dividends and/or distribution of assets.

“Parity Stock” means any equity interest of the Company hereinafter created which by its terms ranks pari passu with the Series A Convertible Preferred Stock.

Dividends

The Series A Convertible Preferred Stock shall participate in any dividends or distributions paid to the holders of Common Stock as if such Series A Convertible Preferred Stock had been converted into Common Stock as of the record date for such dividend or distribution.

Voting Rights

The holders of Series A Convertible Preferred Stock are not entitled to vote on any matters presented to the stockholders for their action or consideration, except as required by law or as otherwise provided in the Certificate of Designations.

Optional Conversion

Holders of Series A Convertible Preferred Stock may convert all of their respective shares of Series A Convertible Preferred Stock into shares of Common Stock at any time, subject to certain ownership limitations set forth in the Certificate of Designations.

Conversion Rate

The number of shares of Common Stock that each holder of Series A Convertible Preferred Stock will receive upon conversion of such holder’s shares of Series A Convertible Preferred Stock will be equal to the quotient of the stated value of the shares of Series A Convertible Preferred Stock to be converted, which is $20.80 per share divided by the Conversion Price, which is $37.13. No fractional shares of Common Stock shall be issued upon the exercise of any conversion right. Any fractional shares of Common Stock that a holder would otherwise be entitled to will be rounded up to the next whole share.

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Adjustments

Holders of Series A Convertible Preferred Stock will have rights to certain adjustments for stock dividends, stock splits and other combinations or subdivisions of its outstanding shares of Common Stock.

Anti-Takeover Provisions

Some provisions of Delaware law, the Second Amended and Restated Certificate of Incorporation, as amended, and the Amended and Restated Bylaws, as amended, contain provisions that could make the following transactions more difficult: an acquisition of us by means of a tender offer, an acquisition of us by means of a proxy contest or otherwise, or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that provide for payment of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board. We believe that the benefits of the increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweighs the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

Delaware Law

We are subject to the provisions of Section 203 of the DGCL regulating corporate takeovers. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date on which the person became an interested stockholder unless:

• prior to the date of the transaction, the board of directors of the corporation approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, but not the outstanding voting stock owned by the interested stockholder, (i) shares owned by persons who are directors and also officers and (ii) shares owned by employee stock plans in which employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; or

• at or subsequent to the date of the transaction, the business combination is approved by the board of directors of the corporation and authorized at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least two-thirds of the outstanding voting stock that is not owned by the interested stockholder.

Generally, a “business combination” includes a merger, asset or stock sale, or other transaction or series of transactions together resulting in a financial benefit to the interested stockholder. An interested stockholder is a person who, together with affiliates and associates, owns or, within three years prior to the determination of interested stockholder status, did own 15% or more of a corporation’s outstanding voting stock. We expect the existence of this provision to have an anti-takeover effect with respect to transactions the board does not approve in advance. We also anticipate that Section 203 may also discourage attempts that might result in a premium over the market price for the shares of common stock held by stockholders.

Organizational Documents Provisions

Provisions of our Organizational Documents could make it more difficult to acquire us by means of a tender offer, a proxy contest or otherwise, or to remove incumbent officers and directors.

Our Second Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, provide for certain provisions that may have an anti-takeover effect:

• a classified board of directors whose members serve staggered three-year terms;

• the authorization of “blank check” preferred stock, which could be issued by our board of directors without stockholder approval and may contain voting, liquidation, dividend and other rights superior to the Common Stock;

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• a limitation on the liability of, and providing indemnification to, our directors and officers;

• a requirement that special meetings of our stockholders can be called only by our board of directors acting by a written resolution by a majority of our directors then in office, the Chairperson of our board of directors, our Chief Executive Officer, or our Lead Independent Director;

• a requirement of advance notice of stockholder proposals for business to be conducted at meetings of our stockholders and for nominations of candidates for election to our board of directors;

• a requirement that our directors may be removed only for cause and by a two-thirds (2/3) vote of the stockholders;

• a prohibition on stockholder action by written consent;

• a requirement that vacancies on our board of directors may be filled only by a majority of directors then in office or by a sole remaining director (subject to limited exceptions), even though less than a quorum; and

• a requirement of the approval of the board of directors or the holders of at least two-thirds of our outstanding shares of capital stock to amend our bylaws and certain provisions of our certificate of incorporation.

Limitation of Liability and Indemnification

Our Amended and Restated Bylaws, as amended, provide that we will indemnify our directors and officers, and may indemnify our employees and other agents, to the fullest extent permitted by Delaware law.

Delaware law prohibits the Second Amended and Restated Certificate of Incorporation, as amended, from limiting the liability of our directors for the following:

• any breach of the director’s duty of loyalty to us or to our stockholders;

• acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law;

• unlawful payment of dividends or unlawful stock repurchases or redemptions; and

• any transaction from which the director derived an improper personal benefit.

If Delaware law is amended to authorize corporate action further eliminating or limiting the personal liability of a director, then the liability of our directors will be eliminated or limited to the fullest extent permitted by Delaware law, as so amended. The Second Amended and Restated Certificate of Incorporation does not eliminate a director’s duty of care and, in appropriate circumstances, equitable remedies, such as injunctive or other forms of non-monetary relief, remain available under Delaware law. This provision also does not affect a director’s responsibilities under any other laws, such as the federal securities laws or other state or federal laws. Under our Amended and Restated Bylaws, as amended, we can purchase insurance on behalf of any person whom we are required or permitted to indemnify.

In addition to the indemnification required in our Organizational Documents, we have entered into an indemnification agreement with each member of our board and each of our officers. These agreements provide for the indemnification of our directors and officers for certain expenses and liabilities incurred in connection with any action, suit, proceeding or alternative dispute resolution mechanism, or hearing, inquiry or investigation that may lead to the foregoing, to which they are a party or other participant, or are threatened to be made a party or other participant, by reason of the fact that they are or were a director, officer, employee, agent or fiduciary of us, by reason of any action or inaction by them while serving as an officer, director, agent or fiduciary, or by reason of the fact that they were serving at our request as a director, officer, employee, agent or fiduciary of another entity. In the case of an action or proceeding by or in the right of the Company, no indemnification will be provided for any claim where a court determines that the indemnified party is prohibited from receiving indemnification. We believe that these certificate of incorporation and bylaw provisions and indemnification agreements are necessary to attract and retain qualified persons as directors and officers.

The limitation of liability and indemnification provisions in our Organizational Documents may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duties. They may also reduce the likelihood of derivative litigation against directors and officers, even though an action, if successful, might benefit us and our stockholders. Moreover, a stockholder’s investment may be harmed to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions.

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Listing of Securities

The Common Stock and Public Warrants are listed on the Nasdaq Capital Market under the symbols “MNTS” and “MNTSW,” respectively.

Transfer Agent and Registrar

The transfer agent and registrar for the Common Stock is Continental Stock Transfer & Trust Company.

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplement and any related free writing prospectus related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture will not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

• the title of the series of debt securities;

• any limit upon the aggregate principal amount that may be issued;

• the maturity date or dates;

• the form of the debt securities of the series;

• the applicability of any guarantees;

• whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

• whether the debt securities rank as senior debt, senior subordinated debt, subordinated debt or any combination thereof, and the terms of any subordination;

• if the price (expressed as a percentage of the aggregate principal amount thereof) at which such debt securities will be issued is a price other than the principal amount thereof, the portion of the principal amount thereof payable upon declaration of acceleration of the maturity thereof, or if applicable, the portion of the principal amount of such debt securities that is convertible into another security or the method by which any such portion shall be determined;

• the interest rate or rates, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the dates interest will be payable and the regular record dates for interest payment dates or the method for determining such dates;

• our right, if any, to defer payment of interest and the maximum length of any such deferral period;

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• if applicable, the date or dates after which, or the period or periods during which, and the price or prices at which, we may, at our option, redeem the series of debt securities pursuant to any optional or provisional redemption provisions and the terms of those redemption provisions;

• the date or dates, if any, on which, and the price or prices at which we are obligated, pursuant to any mandatory sinking fund or analogous fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities and the currency or currency unit in which the debt securities are payable;

• the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof;

• any and all terms, if applicable, relating to any auction or remarketing of the debt securities of that series and any security for our obligations with respect to such debt securities and any other terms which may be advisable in connection with the marketing of debt securities of that series;

• any and all terms, if applicable, relating to any auction or remarketing of the debt securities of that series and any security for our obligations with respect to such debt securities and any other terms which may be advisable in connection with the marketing of debt securities of that series;

• any and all terms, if applicable, relating to any auction or remarketing of the debt securities of that series and any security for our obligations with respect to such debt securities and any other terms which may be advisable in connection with the marketing of debt securities of that series;

• whether the debt securities of the series shall be issued in whole or in part in the form of a global security or securities; the terms and conditions, if any, upon which such global security or securities may be exchanged in whole or in part for other individual securities; and the depositary for such global security or securities;

• if applicable, the provisions relating to conversion or exchange of any debt securities of the series and the terms and conditions upon which such debt securities will be so convertible or exchangeable, including the conversion or exchange price, as applicable, or how it will be calculated and may be adjusted, any mandatory or optional (at our option or the holders’ option) conversion or exchange features, the applicable conversion or exchange period and the manner of settlement for any conversion or exchange;

• if other than the full principal amount thereof, the portion of the principal amount of debt securities of the series which shall be payable upon declaration of acceleration of the maturity thereof;

• additions to or changes in the covenants applicable to the particular debt securities being issued, including, among others, the consolidation, merger or sale covenant;

• additions to or changes in the events of default with respect to the securities and any change in the right of the trustee or the holders to declare the principal, premium, if any, and interest, if any, with respect to such securities to be due and payable;

• additions to or changes in or deletions of the provisions relating to covenant defeasance and legal defeasance;

• additions to or changes in the provisions relating to satisfaction and discharge of the indenture;

• additions to or changes in the provisions relating to the modification of the indenture both with and without the consent of holders of debt securities issued under the indenture;

• the currency of payment of debt securities if other than U.S. dollars and the manner of determining the equivalent amount in U.S. dollars;

• whether interest will be payable in cash or additional debt securities at our or the holders’ option and the terms and conditions upon which the election may be made;

• the terms and conditions, if any, upon which we will pay amounts in addition to the stated interest, premium, if any and principal amounts of the debt securities of the series to any holder that is not a “United States person” for federal tax purposes;

• any restrictions on transfer, sale or assignment of the debt securities of the series; and

• any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities, any other additions or changes in the provisions of the indenture, and any terms that may be required by us or advisable under applicable laws or regulations.

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Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than a subsidiary of ours) must assume all of our obligations under the indenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

• if we fail to pay any installment of interest on any series of debt securities, as and when the same shall become due and payable, and such default continues for a period of 90 days; provided, however, that a valid extension of an interest payment period by us in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of interest for this purpose;

• if we fail to pay the principal of, or premium, if any, on any series of debt securities as and when the same shall become due and payable whether at maturity, upon redemption, by declaration or otherwise, or in any payment required by any sinking or analogous fund established with respect to such series; provided, however, that a valid extension of the maturity of such debt securities in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of principal or premium, if any;

• if we fail to observe or perform any other covenant or agreement contained in the debt securities or the indenture, other than a covenant specifically relating to another series of debt securities, and our failure continues for 90 days after we receive written notice of such failure, requiring the same to be remedied and stating that such is a notice of default thereunder, from the trustee or holders of at least 25% in aggregate principal amount of the outstanding debt securities of the applicable series; and

• if specified events of bankruptcy, insolvency or reorganization occur.

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

• the direction so given by the holder is not in conflict with any law or the applicable indenture; and

• subject to its duties under the Trust Indenture Act, the trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

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A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

• the holder has given written notice to the trustee of a continuing event of default with respect to that series;

• the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series have made written request,

• such holders have offered to the trustee indemnity satisfactory to it against the costs, expenses and liabilities to be incurred by the trustee in compliance with the request; and

• the trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series other conflicting directions within 90 days after the notice, request and offer.

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

• to cure any ambiguity, defect or inconsistency in the indenture or in the debt securities of any series;

• to comply with the provisions described above under “Description of Debt Securities—Consolidation, Merger or Sale;”

• to provide for uncertificated debt securities in addition to or in place of certificated debt securities;

• to add to our covenants, restrictions, conditions or provisions such new covenants, restrictions, conditions or provisions for the benefit of the holders of all or any series of debt securities, to make the occurrence, or the occurrence and the continuance, of a default in any such additional covenants, restrictions, conditions or provisions an event of default or to surrender any right or power conferred upon us in the indenture;

• to add to, delete from or revise the conditions, limitations, and restrictions on the authorized amount, terms, or purposes of issue, authentication and delivery of debt securities, as set forth in the indenture;

• to make any change that does not adversely affect the interests of any holder of debt securities of any series in any material respect;

• to provide for the issuance of and establish the form and terms and conditions of the debt securities of any series as provided above under “Description of Debt Securities—General” to establish the form of any certifications required to be furnished pursuant to the terms of the indenture or any series of debt securities, or to add to the rights of the holders of any series of debt securities;

• to evidence and provide for the acceptance of appointment under any indenture by a successor trustee; or

• to comply with any requirements of the SEC in connection with the qualification of any indenture under the Trust Indenture Act.

In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

• extending the fixed maturity of any debt securities of any series;

• reducing the principal amount, reducing the rate of or extending the time of payment of interest, or reducing any premium payable upon the redemption of any series of any debt securities; or

• reducing the percentage of debt securities, the holders of which are required to consent to any amendment, supplement, modification or waiver.

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Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

• provide for payment;

• register the transfer or exchange of debt securities of the series;

• replace stolen, lost or mutilated debt securities of the series;

• pay principal of and premium and interest on any debt securities of the series;

• maintain paying agencies;

• hold monies for payment in trust;

• recover excess money held by the trustee;

• compensate and indemnify the trustee; and

• appoint any successor trustee.

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company, or DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating such securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer

agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

• issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

• register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

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Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplement and in any related free writing prospectus, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed or will file forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectus, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms of the series of warrants being offered, including, to the extent applicable:

• the offering price and aggregate number of warrants offered;

• the currency for which the warrants may be purchased;

• the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each such security or each principal amount of such security;

• the date on and after which the warrants and the related securities will be separately transferable;

• in the case of warrants to purchase debt securities, the principal amount of debt securities purchasable upon exercise of one warrant and the price at, and currency in which, this principal amount of debt securities may be purchased upon such exercise;

• in the case of warrants to purchase common stock or preferred stock, the number of shares of common stock or preferred stock, as the case may be, purchasable upon the exercise of one warrant and the price at which these shares may be purchased upon such exercise;

• the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreements and the warrants;

• the terms of any rights to redeem or call the warrants;

• any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

• the dates on which the right to exercise the warrants will commence and expire;

• the manner in which the warrant agreements and warrants may be modified;

• a discussion of material United States federal income tax consequences of holding or exercising the warrants;

• the terms of the securities issuable upon exercise of the warrants; and

• any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

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Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

• in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or, payments upon our liquidation, dissolution or winding up or to exercise voting rights, if any; or

• in the case of warrants to purchase debt securities, the right to receive payments of principal of, or premium, if any, or interest on, the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants by delivering the warrant or warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent, if applicable, in immediately available funds, as provided in the applicable prospectus supplement. We will set forth on the reverse side of any warrant certificate and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to any warrant agent in connection with the exercise of the warrant.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Governing Law

Unless we provide otherwise in the applicable prospectus supplement, the warrants and warrant agreements, and any claim, controversy or dispute arising under or related to the warrants or warrant agreements, will be governed by and construed in accordance with the laws of the State of New York.

Enforceability of Rights by Holders of Warrants

Each warrant agent, if any, will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

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DESCRIPTION OF UNITS

The following description, together with the additional information we may include in any applicable prospectus supplement and related free writing prospectus, summarizes the material terms and provisions of the units that we may offer under this prospectus. We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We will issue each unit so that the holder of the unit is also the holder of each security included in the unit. As a result, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of any unit agent in the applicable prospectus supplement relating to a particular series of units. The summary below and that contained in any prospectus supplement is qualified in its entirety by reference to all of the provisions of the unit agreement and/or unit certificate, and depositary arrangements, if applicable. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the units that we may offer under this prospectus, as well as the complete unit agreement and/or unit certificate, and depositary arrangements, as applicable, that contain the terms of the units.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of unit agreement and/or unit certificate, and depositary arrangements, as applicable, that contain the terms of the particular series of units we are offering, and any supplemental agreements, before the issuance of such units.

We will describe in the applicable prospectus supplement the terms of the series of units being offered, including:

• the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

• any provisions for the issuance, payment, settlement, transfer, or exchange of the units or of the securities composing the units;

• whether the units will be issued in fully registered or global form; and

• any other terms of the units.

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LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Global securities will be registered in the name of the depositary or its participants. Consequently, for global securities, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee or third party employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with its participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the legal holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

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Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

• how it handles securities payments and notices;

• whether it imposes fees or charges;

• how it would handle a request for the holders’ consent, if ever required;

• whether and how you can instruct it to send you securities registered in your own name so you can be a holder, if that is permitted in the future;

• how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

• if the securities are in book-entry form, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “—Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations for Global Securities

As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only as global securities, an investor should be aware of the following:

• an investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations we describe below;

• an investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as we describe above;

• an investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

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• an investor may not be able to pledge his or her interest in the global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

• the depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in the global security;

• we and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in the global security, nor will we or any applicable trustee supervise the depositary in any way;

• the depositary may, and we understand that DTC will, require that those who purchase and sell interests in the global security within its book-entry system use immediately available funds, and your broker or bank may require you to do so as well; and

• financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in the global security, may also have their own policies affecting payments, notices and other matters relating to the securities.

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own names, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, a global security will terminate when the following special situations occur:

• if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

• if we notify any applicable trustee that we wish to terminate that global security; or

• if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and neither we nor any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

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PLAN OF DISTRIBUTION

We may sell the securities from time to time pursuant to underwritten public offerings, direct sales to the public, “at the market” offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through one or more underwriters or dealers (acting as principal or agent), through agents, or directly to one or more purchasers. We may distribute securities from time to time in one or more transactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

A prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you) will describe the terms of the offering of the securities, including, to the extent applicable:

• the name or names of the underwriters, dealers, agents or other purchasers, if any;

• the purchase price of the securities or other consideration therefor, and the proceeds we will receive from the sale;

• any option to purchase additional shares or other options under which underwriters, dealers, agents or other purchasers may purchase additional securities from us;

• any agency fees or underwriting discounts to be allowed or paid to the agent or underwriters and other items constituting agents’ or underwriters’ compensation;

• any public offering price;

• any discounts or concessions allowed or reallowed or paid to dealers; and

• any securities exchange or market on which the securities may be listed.

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement other than securities covered by any option to purchase additional shares or other option. If a dealer is used in the sale of securities, we, or an underwriter, will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale. To the extent required, we will set forth in the prospectus supplement the name of the dealer and the terms of the transaction. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time. We may use underwriters, dealers or agents with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, dealer or agent, the nature of any such relationship.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities, and we will describe any commissions we will pay the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, the agent will act on a best-efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

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We may provide agents, dealers and underwriters with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents, dealers or underwriters may make with respect to these liabilities. Agents, dealers and underwriters or their affiliates may engage in transactions with, or perform services for, us in the ordinary course of business.

All securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate covering or other short-covering transactions involve purchases of the securities, either through exercise of the option to purchase additional shares or in the open market after the distribution is completed, to cover short positions. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time. These transactions may be effected on any exchange or over-the-counter market or otherwise.

Any underwriters, dealers or agents that are qualified market makers on Nasdaq may engage in passive market making transactions in our common stock on Nasdaq in accordance Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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LEGAL MATTERS

The validity of the securities offered hereby will be passed upon for us by Bradley Arant Boult Cummings LLP. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of the Company and subsidiaries as of and for the year ended December 31, 2025 and 2024, incorporated by reference in this prospectus, have been audited by Frank, Rimerman + Co. LLP, an independent registered public accounting firm, as stated in their report. Such consolidated financial statements are incorporated by reference in reliance upon the report of such firm given their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the periodic reporting requirements of the Exchange Act, and we will file periodic reports, proxy statements and other information with the SEC. These periodic reports, proxy statements and other information are available at www.sec.gov. We also maintain a website at www.momentus.space, at which you may access these materials free of charge as soon as reasonably practicable after they are electronically filed with, or furnished to, the SEC. Information contained on or accessible through our website is not a part of this prospectus, and the inclusion of our website address in this prospectus is an inactive textual reference only. We will provide you without charge, upon your oral or written request, with a copy of any or all reports, proxy statements and other documents we file with the SEC, as well as any or all of the documents incorporated by reference in this prospectus or the registration statement (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into such documents). Requests for such copies should be directed to:

Momentus Inc.

Attn: John C. Rood

Chief Executive Officer

1762 Automation Parkway

San Jose, CA 95131

Telephone: (650) 564-7820

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus.

We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-12584):

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, filed with the SEC on March 31, 2026;

• our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2026, filed with the SEC on May 13, 2026;

• our Definitive Proxy Statement on Schedule 14A, filed with the SEC on April 10, 2026;

• the description of our Common Stock contained in Exhibit 4.19 to our Registration Statement on Form S-1, as filed with the SEC on April 21, 2025, and including any further amendment or report filed for the purpose of updating such description; and

• our Current Reports filed on Form 8-K with the SEC on January 9, 2026, January 13, 2026, February 12, 2026, February 20, 2026, April 13, 2026, April 16, 2026, April 20, 2026, and May 5, 2026.

All reports and other documents that we file with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act on or after the date of the filing of the registration statement of which this prospectus forms a part and prior to effectiveness of the registration statement, and on or after the date of this prospectus but before the termination of the offering of the securities hereunder will also be considered to be incorporated by reference into this prospectus from the date of the filing of these reports and documents, and will supersede the information herein; provided, however, that all reports, exhibits and other information that we “furnish” to the SEC will not be considered incorporated by reference into this prospectus. We undertake to provide without charge to each person (including any beneficial owner) who receives a copy of this prospectus, upon written or oral request, a copy of all of the preceding documents that are incorporated by reference (other than exhibits, unless the exhibits are specifically incorporated by reference into these documents). You may request a copy of these materials in the manner set forth under the heading “Where You Can Find More Information,” above.

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Up to $200,000,000

of

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

Prospectus

  , 2026

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PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14.
Other Expenses of Issuance and Distribution.

The following sets forth the estimated costs and expenses, all of which shall be borne by Momentus Inc. (the “Registrant”), in connection with the offering of the securities pursuant to this registration statement.

SEC registration fee			$27,620
Transfer agent and registrar expenses			(1)
Accounting fees and expenses			(1)
Legal fees and expenses			(1)
Printing and engraving expenses			(1)
Miscellaneous			(1)
Total			$    (1)

(1)
These fees are calculated based on the securities offered and the number of issuances and, accordingly, cannot be estimated at this time. An estimate of the aggregate expenses in connection with the sale and distribution of securities being offered will be included in the applicable prospectus supplement.

Item 15.
Indemnification of Directors and Officers.

Section 145 of the Delaware General Corporation Law (the “DGCL”) provides that a corporation may indemnify directors and officers as well as other employees and individuals against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any threatened, pending or completed actions, suits or proceedings in which such person is made a party by reason of such person being or having been a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise. The DGCL provides that Section 145 is not exclusive of other rights to which those seeking indemnification may be entitled under any bylaws, agreement, vote of stockholders or disinterested directors or otherwise. The registrant’s Second Amended and Restated Certificate of Incorporation, as amended, and Amended and Restated Bylaws, as amended, provide for indemnification by the registrant of its directors and officers to the fullest extent permitted by the DGCL.

Section 102(b)(7) of the DGCL permits a corporation to provide in its certificate of incorporation that a director of the corporation shall not be personally liable to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except for liability (1) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (2) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (3) for unlawful payments of dividends or unlawful stock repurchases, redemptions or other distributions, or (4) for any transaction from which the director derived an improper personal benefit. The registrant’s Second Amended and Restated Certificate of Incorporation, as amended, provides for such limitation of liability to the fullest extent permitted by the DGCL.

The registrant has entered into, and expects to continue to enter into, indemnification agreements with each of its directors and executive officers. These agreements provide that the registrant will indemnify each of its directors and such officers to the fullest extent permitted by law.

Any underwriting agreement or distribution agreement that the registrant enters into with any underwriters or agents involved in the offering or sale of any securities registered hereby may require such underwriters or dealers to indemnify the registrant, some or all of its directors and officers and its controlling persons, if any, for specified liabilities, which may include liabilities under the Securities Act.

The registrant also maintains standard policies of insurance under which coverage is provided to its directors and officers against loss arising from claims made by reason of breach of duty or other wrongful act, while acting in their capacity as directors and officers of the registrant.

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Item 16.
Exhibits.

The exhibits to this registration statement are listed in the Exhibit Index to this registration statement, which immediately precedes the Signature Page and which Exhibit Index is hereby incorporated by reference.

Item 17.
Undertakings.

The undersigned registrant hereby undertakes:

(1)
To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i)
To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii)
To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii)
To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that are incorporated by reference in this registration statement or are contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

(2)
That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)
To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)
That, for the purpose of determining liability under the Securities Act to any purchaser:

(i)
Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii)
Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

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(5)
That, for the purpose of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i)
any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii)
any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii)
the portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv)
any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6)
That, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7)
To file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

(8)
Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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EXHIBIT INDEX

Exhibit Number			Description of Exhibit
1.1			Sales Agreement, dated September 19, 2025, by and between Momentus Inc. and Alliance Global Partners (incorporated by reference to Exhibit 1.1 to the Company’s Registration Statement on Form S-3 (File No. 333-290425) filed on September 22, 2025).
1.2**			Form of Underwriting Agreement
2.1†			Agreement and Plan of Merger, dated as of October 7, 2020, by and among Stable Road Acquisition Corp., Project Marvel First Merger Sub, Inc., Project Marvel Second Merger Sub, LLC, and Momentus Inc. (incorporated by reference to Exhibit 2.1 to the Company’s Current Report on Form 8-K filed on October 7, 2020).
2.2			Amendment No. 1 to Agreement and Plan of Merger, dated March 5, 2021, by and among Stable Road Acquisition Corp., Project Marvel First Merger Sub, Inc., Project Marvel Second Merger Sub, LLC, and Momentus Inc. (incorporated by reference to Exhibit 2.2 to the Company’s Registration Statement on Form S-4 (Registration No. 333-249787) filed on March 8, 2021).
2.3			Amendment No. 2 to Agreement and Plan of Merger, dated as of April 6, 2021, by and among Stable Road Acquisition Corp., Project Marvel First Merger Sub, Inc., Project Marvel Second Merger Sub, LLC, and Momentus Inc. (incorporated by reference to Exhibit 2.1 to the Company’s Current Report on Form 8-K filed on April 8, 2021).
2.4			Amendment No. 3 to Agreement and Plan of Merger, dated as of June 29, 2021, by and among Stable Road Acquisition Corp., Project Marvel First Merger Sub, Inc., Project Marvel Second Merger Sub, LLC, and Momentus Inc. (incorporated by reference to Exhibit 2.1 to the Company’s Current Report on Form 8-K filed on June 29, 2021).
4.1			Warrant Agreement, dated November 7, 2019, between Continental Stock Transfer & Trust Company and SRAC (incorporated by reference to the Company’s Current Report on Form 8-K filed on November 13, 2019).
4.2			Specimen Warrant Certificate (incorporated by reference to Exhibit 4.3 to the Company’s Registration Statement on Form S-1 (Registration No. 333-233980) filed on October 10, 2019).
4.3			Form of Class A Warrant (incorporated by reference to Exhibit 4.2 to the Company’s Current Report on Form 8-K filed on September 16, 2024).
4.4			Form of Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on December 16, 2024).
4.5			Form of Common Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on December 18, 2024).
4.6			Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.3 to the Company’s Current Report on Form 8-K filed on December 18, 2024).
4.7			Form of Common Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on February 13, 2025).
4.8			Amendment to Common Stock Purchase Warrants (incorporated by reference to Exhibit 4.3 to the Company’s Current Report on Form 8-K filed on February 13, 2025).
4.9			Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.4 to the Company’s Current Report on Form 8-K filed on February 13, 2025).
4.10			Form of Inducement Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on March 21, 2025).
4.11			Description of Securities (incorporated by reference to Exhibit 4.19 to the Company’s Registration Statement on Form S-1 filed on April 21, 2025).
4.12			Form of Common Stock Purchase Warrant (incorporated by reference to Exhibit 4.12 to the Company’s Registration Statement on Form S-1 (Registration No. 333-287712) filed on May 30, 2025).
4.13			Form of Common Stock Purchase Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on July 2, 2025).
4.14			Amendment to Common Stock Purchase Warrants (incorporated by reference to Exhibit 4.3 to the Company’s Current Report on Form 8-K filed on July 2, 2025).
4.15			Form of Inducement Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on August 14, 2025).

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Exhibit Number			Description of Exhibit
4.16			Form of Class A Common Stock Purchase Warrant (incorporated by reference to Exhibit C to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed on September 11, 2025).
4.17			Junior Secured Convertible Note Due September 25, 2026, dated September 25, 2025, between Momentus Inc. and Yield Point NY, LLC (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on September 29, 2025).
4.18			Common Stock Purchase Warrant, dated September 25, 2025, between Momentus Inc. and Yield Point NY, LLC (incorporated by reference to Exhibit 4.2 to the Company’s Current Report on Form 8-K filed on September 29, 2025).
4.19			AIR Warrant, dated September 25, 2025, between Momentus Inc. and Yield Point NY, LLC (incorporated by reference to Exhibit 4.3 to the Company’s Current Report on Form 8-K filed on September 29, 2025).
4.20			Pre-Funded Common Stock Purchase Warrant, dated September 25, 2025, between Momentus Inc. and Yield Point NY, LLC (incorporated by reference to Exhibit 4.4 to the Company’s Current Report on Form 8-K filed on September 29, 2025).
4.21			Pre-Funded Common Stock Purchase Warrant, dated September 30, 2025, between Momentus Inc. and Baker & McKenzie LLP (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on October 6, 2025).
4.22			Form of Inducement Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on October 15, 2025).
4.23			Form of Inducement Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on December 12, 2025).
4.24			Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on January 9, 2026).
4.25			Form of Common Warrant (incorporated by reference to Exhibit 4.2 to the Company’s Current Report on Form 8-K filed on January 9, 2026).
4.26			Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed on April 16, 2026).
4.27			Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.2 to the Company’s Current Report on Form 8-K filed on April 16, 2026).
4.28			Form of Senior Indenture (incorporated by reference to Exhibit 4.17 to the Company’s Registration Statement on Form S-3 (File No. 333-290425) filed on September 22, 2025).
4.29			Form of Subordinated Indenture (incorporated by reference to Exhibit 4.18 to the Company’s Registration Statement on Form S-3 (File No. 333-290425) filed on September 22, 2025).
4.30**			Form of Preferred Stock Certificate
4.31**			Form of Senior Note
4.32**			Form of Subordinated Note
4.33**			Form of Warrant Agreement and Warrant Certificate
5.1*			Opinion of Bradley Arant Boult Cummings LLP.
23.1*			Consent of Frank, Rimerman + Co. LLP, independent registered public accounting firm.
23.2			Consent of Bradley Arant Boult Cummings LLP (included in Exhibit 5.1).
24.1*			Power of Attorney (included on the signature page to the prospectus which forms part of this registration statement).
25.1#			Form T-1 Statement on Eligibility of Trustee for Senior Indenture under the Trust Indenture Act of 1939.
25.2#			Form T-1 Statement on Eligibility of Trustee for Subordinate Indenture under the Trust Indenture Act of 1939.
107*			Filing Fee Table.

†
Certain of the exhibits and schedules to this Exhibit List have been omitted in accordance with Regulation S-K Item 601(a)(5). The registrant agrees to furnish a copy of all omitted exhibits and schedules to the SEC upon its request.

*
Filed herewith

**
To be filed by amendment or by a report on Form 8-K pursuant to Item 601 of Regulation S-K and incorporated herein by reference.

#
To be incorporated herein by reference from a subsequent filing in accordance with Section 305(b)(2) of the Trust Indenture Act of 1939.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized on May 22, 2026.

			MOMENTUS INC.
			By:			/s/ Lon Ensler
			Name:			Lon Ensler
			Title:			Chief Financial Officer

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints John C. Rood and Lon Ensler, and each and either of them, his true and lawful agent, proxy and attorney-in-fact, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to (i) act on, sign and file with the Securities and Exchange Commission any and all amendments (including post-effective amendments) to this registration statement together with all schedules and exhibits thereto and any subsequent registration statement filed pursuant to Rule 462(b) under the Securities Act, together with all schedules and exhibits thereto, (ii) act on, sign and file such certificates, instruments, agreements and other documents as may be necessary or appropriate in connection therewith, (iii) act on and file any supplement to any prospectus included in this registration statement or any such amendment or any subsequent registration statement filed pursuant to Rule 462(b) under the Securities Act and (iv) take any and all actions which may be necessary or appropriate to be done, as fully for all intents and purposes as he might or could do in person, hereby approving, ratifying and confirming all that such agent, proxy and attorney-in-fact or any of his substitutes may lawfully do or cause to be done by virtue thereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

Signature			Title			Date
/s/ John C. Rood			Chief Executive Officer and Director (Principal Executive Officer)			May 22, 2026
John C. Rood
/s/ Lon Ensler			Chief Financial Officer (Principal Financial and Accounting Officer)			May 22, 2026
Lon Ensler
/s/ Brian Kabot			Director			May 22, 2026
Brian Kabot
/s/ Chris Hadfield			Director			May 22, 2026
Chris Hadfield
/s/ Victorino Mercado			Director			May 22, 2026
Victorino Mercado
/s/ Kimberly A. Reed			Director			May 22, 2026
Kimberly A. Reed
/s/ Linda J. Reiners			Director			May 22, 2026
Linda J. Reiners
/s/ Mitchel B. Kugler			Director			May 22, 2026
Mitchel B. Kugler

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FAQ

What does Momentus (MNTS) register with this Form S-3?

Momentus registers up to $200,000,000 of securities on a shelf, including common stock, preferred stock, debt securities, warrants and units. Specific amounts, prices and terms will be provided in prospectus supplements for each offering.

How did the January 2026 private placement affect Momentus' cash position?

The January 2026 private placement produced approximately $5.0 million gross and about $4.58 million net proceeds after placement agent fees. The company states net proceeds are for working capital and general corporate purposes.

What securities were issued in the April 2026 financing?

In April 2026 Momentus sold 450,000 shares of common stock and issued pre-funded warrants to purchase up to 883,334 shares. The stated purchase price per share was $3.75 and the pre-funded warrant price was $3.74999.

How many shares of common stock were outstanding as disclosed?

The filing reports 10,547,553 shares of common stock issued and outstanding as of May 21, 2026. The prospectus also notes aggregate market value of non-affiliate holdings of approximately $79.8 million based on prior-period pricing.

What will Momentus use proceeds from offerings under this prospectus for?

Momentus states it will retain broad discretion but currently intends to use net proceeds primarily for working capital and general corporate purposes, including possible debt repayment, capital expenditures, and funding operations.