Initial Registration Statement for Employee Benefit Plan (Form S-8)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

MOMENTUS INC.

(Exact Name of Registrant as Specified in Its Charter)

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)

Momentus Inc. 2021 Equity Incentive Plan

(Full Title of the Plans)

John C. Rood

Chief Executive Officer

1762 Automation Parkway

San Jose, CA 95131

Telephone: (650) 564-7820

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

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 definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

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 pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

EXPLANATORY NOTE

This Registration Statement on Form S-8 is being filed by Momentus Inc. (the "Company") to register 500,000 additional shares of the Company's Class A Common Stock, par value $0.00001 per share ("Common Stock"), reserved for issuance under the Company's 2021 Equity Incentive Plan (the "2021 Plan"), which was approved by our stockholders at the 2026 Annual Meeting of Stockholders held on May 19, 2026.

Pursuant to General Instruction E regarding Registration of Additional Securities, the contents of the Registration Statements on Form S-8 filed with the Securities and Exchange Commission (the "Commission") on February 2, 2026 (Registration No. 333-293128), May 30, 2025 (Registration No. 333-287706), March 23, 2023 (Registration No. 333-270762), March 14, 2022 (Registration No. 333-263524), and October 18, 2021 (Registration No. 333-260331) are incorporated by reference herein except as otherwise updated or modified by this filing. All exhibits required by General Instruction E to Form S-8 are filed as exhibits hereto.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.

Incorporation of Documents by Reference

The Registrant hereby incorporates by reference into this Registration Statement the following documents previously filed with the Commission (other than information in a report on Form 8-K that is furnished and not filed pursuant to Form 8-K and, except as may be noted in any such Form 8-K, exhibits filed on such form that are related to such information):

All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act after the date of this Registration Statement and prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which deregisters all securities then remaining unsold shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the date of filing of such documents; provided, however, that documents or information deemed to have been furnished, and exhibits furnished in connection with such items, and not filed in accordance with the rules of the Commission shall not be deemed incorporated by reference into this Registration Statement.

Item 8.

Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Jose, State of California, on May 22, 2026.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned officers and directors of Momentus Inc., a Delaware corporation, do hereby constitute and appoint John C. Rood and Lon Ensler, and each of them, the lawful attorneys-in-fact and agents with full power and authority to do any and all acts and things and to execute any and all instruments which said attorneys and agents, and any one of them, determine may be necessary or advisable or required to enable said corporation to comply with the Securities Act of 1933, as amended, and any rules or regulations or requirements of the Securities and Exchange Commission in connection with this Registration Statement. Without limiting the generality of the foregoing power and authority, the powers granted include the power and authority to sign the names of the undersigned officers and directors in the capacities indicated below to this Registration Statement, to any and all amendments, both pre-effective and post-effective, and supplements to this Registration Statement, and to any and all instruments or documents filed as part of or in conjunction with this Registration Statement or amendments or supplements thereof, and each of the undersigned hereby ratifies and confirms that all said attorneys and agents, or any one of them, shall do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons on behalf of the Registrant in the capacities and on the dates indicated.