Sec Form 4 Filing - Vector Acquisition Partners, L.P. @ Rocket Lab USA, Inc. - 2021-08-25

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Vector Acquisition Partners, L.P. 2. Issuer Name and Ticker or Trading Symbol Rocket Lab USA, Inc. [ RKLB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) ONE MARKET STREET, 23RD FLOOR, 3. Date of Earliest Transaction (MM/DD/YY) 08/25/2021 (Street) SAN FRANCISCO, CA94105 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Vector Acquisition Partners, L.P. ONE MARKET STREET, 23RD FLOOR SAN FRANCISCO, CA94105 X Vector Capital Partners V, Ltd ONE MARKET STREET, 23RD FL. STEUART TOWER SAN FRANCISCO, CA94105 X Signatures /s/ See signatures included in Exhibit 99.1 08/27/2021 Signature of Reporting Person Date /s/ See signatures included in Exhibit 99.1 08/27/2021 Signature of Reporting Person Date

Explanation of Responses:

Remarks: 1. In connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated March 1, 2021, by and among Vector Acquisition Corporation, Rocket Lab USA, Inc. and Prestige USA Merger Sub, as amended to the date hereof, Vector Acquisition Partners, L.P., and its general partner, Vector Capital Partners V, Ltd., ceased to be insiders of the issuer. 2. This Form 4 was previously filed on August 27, 2021 under the wrong CIK# and is being resubmitted under the correct CIK#.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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