ASTRA SPACE, INC.

Primary Offering Of

15,333,303 Shares of Common Stock

Secondary Offering of

189,026,575 Shares of Common Stock

5,333,333 Warrants to Purchase Common Stock

This prospectus supplement amends and supplements the prospectus dated August 12, 2021 (as supplemented or amended from time to time, the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (No. 333-257930). This prospectus supplement is being filed to update and supplement the information in the Prospectus with the information contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commission on August 24, 2021 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.

The Prospectus and this prospectus supplement relate to the issuance by us of up to an aggregate of (i) 9,999,970 shares of our Class A common stock that may be issued upon exercise of warrants to purchase Class A common stock at an exercise price of $11.50 per share (the “public warrants”) issued by Holicity Inc. (“Holicity”) in its initial public offering; and (ii) 5,333,333 shares of our Class A common stock that may be issued upon exercise of private placement warrants at an exercise price of $11.50 per share that were originally sold to X-icity Holdings Corporation (the “Sponsor”) in a private placement consummated simultaneously with Holicity’s IPO (the “private placement warrants” and, together with the public warrants, the “warrants”).

The Prospectus and this prospectus supplement also relate to the offer and sale, from time to time, by the selling securityholders named in this prospectus (the “Selling Securityholders”), or any of their permitted transferees, of (i) 5,333,333 private placement warrants; (ii) up to an aggregate of 5,333,333 shares of our Class A common stock that may be issued upon exercise of the private placement warrants held by the Selling Securityholders; (iii) up to an aggregate of 20,000,000 shares of our Class A common stock that were issued to certain investors (collectively, the “PIPE Investors”) in a private placement in connection with the closing of the Business Combination (as defined herein); (iv) 7,500,000 shares of Class A common stock issued to the Sponsor prior to Holicity’s initial public offering and registered for sale by the Selling Securityholders; (v) up to an aggregate of 92,277,793 shares of Class A common stock that were issued to certain affiliates of Astra (collectively, the “Astra Affiliates”) pursuant to the Business Combination Agreement (as defined herein); (vi) up to an aggregate 56,239,188 shares of Class A common stock issuable upon conversion (on a one-for-one basis) of shares of our Class B common stock, par value $0.0001 per share (“Class B Common Stock”) held by certain Selling Securityholders and (vii) up to an aggregate of 7,676,261 shares of our Class A common stock issued in connection with our acquisition of Apollo Fusion, Inc. (“Apollo Fusion”), which closed on July 1, 2021 comprised of (x) 2,558,744 shares of our Class A common stock (the “Initial Apollo Shares”) issued to certain of the Selling Securityholders on July 1, 2021, in connection with our merger with Apollo Fusion, Inc. (“Apollo Fusion”) and (y) 5,117,517 additional shares of our Class A common stock (the “Additional Apollo Shares”) which may be issued to certain of the Selling Securityholders assuming (a) the achievement of all remaining performance milestones set forth in the Apollo Fusion Merger Agreement (as defined herein), (b) we elect to pay all future milestone consideration in shares of our Class A common stock as required by the terms the Apollo Fusion Merger Agreement, and (c) the per share price used to calculate the number of shares of our Class A common stock to be issued is $11.7243, which is the same per share price used to calculate the number of Initial Shares issued to the Selling Securityholders. The Additional Shares have not been earned and

are not currently outstanding. The actual number of Additional Shares issued to the selling stockholders could be materially greater or less than 5,117,517 shares of Class A common stock depending whether and to what extent the future performance milestones are met and/or the actual average closing price of our Class A common stock at the time such milestones are achieved. The Prospectus and this prospectus supplement also cover any additional securities that may become issuable by reason of share splits, share dividends or other similar transactions.

Our common stock and warrants are listed on Nasdaq under the symbols “ASTR” and “ASTRW”, respectively. On August 23, 2021, the closing price of our common stock was $10.58 per share and the closing price of our warrants was $3.15 per share.

This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement.

Investing in our securities involves risks that are described in the “Risk Factors” section beginning on page 15 of the Prospectus.

Neither the SEC nor any state securities commission has approved or disapproved of the securities to be issued under the Prospectus or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is August 24, 2021.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 20, 2021

Astra Space, Inc.

(Exact name of Registrant as Specified in Its Charter)

Registrant’s Telephone Number, Including Area Code: (866) 278-7217

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

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 pursuant to Section 13(a) of the Exchange Act.  ☐

Item 8.01 Other Events.

On August 24, 2021, we issued a press release announcing the successful orbital ignition of Apollo Fusion’s thruster in the Spaceflight Sherpa program, which occurred on August 20, 2021. A copy of our press release is filed as Exhibit 99.1 hereto.

A live stream of our previously announced first commercial orbital launch will be posted on our website at www.astra.com/livestream. The launch window opens on August 27, 2021. We will provide updates on the timing of our launch through our Twitter account: @astra.    When we use the phrase “commercial orbital launch,” we mean a launch conducted under a FAA Commercial Launch License.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Exhibit 99.1

Astra’s Apollo Fusion Thruster Ignites on First Attempt in Orbit with Spaceflight

Ignition demonstrates reliable electric propulsion (EP) system

Alameda, CA. August 24, 2021. Astra Space, Inc. (“Astra”) (Nasdaq: ASTR), today announced the successful orbital ignition of its Apollo Fusion thruster on board the Spaceflight Sherpa-LTE1 orbital transfer vehicle (OTV). The Sherpa OTV launched June 30, 2021 from SpaceX’s Transporter-2 mission from Cape Canaveral, Florida. After successfully deploying all rideshare payloads, Spaceflight commissioned the Apollo Fusion thruster, representing Astra’s first attempt at firing the thruster in orbit.

“The telemetry from the on-orbit firing looked excellent and closely matched our ground test results,” said Mike Cassidy, Vice President of Product Management at Astra. “We expect to deliver thrusters for additional satellites over the next quarter and these on-orbit test results provide further validation for several programs for which we are supplying propulsion systems.”

“This represents the industry’s first fully functional electric propulsion OTV,” said Philip Bracken, VP of Engineering at Spaceflight. “Our next-gen Sherpa OTVs were intentionally designed for maximum modularity, flexibility and rapid development including offering several innovative propulsion solutions. The successful commissioning and ignition of Apollo Fusion’s system paves the way for expanding orbital destinations for smallsats and is paramount in achieving our goal of getting our customers’ payloads to space whenever and wherever they want.”

Astra acquired Apollo Fusion in July 2021 to leverage Apollo Fusion’s shared focus on designing and manufacturing products at scale that can reach destinations beyond low Earth orbit.

“We’re incredibly proud of everyone who built this EP system,” said Benjamin Lyon, Chief Engineer at Astra. “This is an important milestone on our journey to provide rapid, low-cost access to space.”

About Astra Space

Astra’s mission is to improve life on Earth from space by creating a healthier and more connected planet. Astra’s first flight to space was within 4 years of its inception, making it the fastest company to reach space. Visit www.astra.com to learn more about Astra.

Safe Harbor Statement

Certain statements made in this press release are “forward-looking statements”. Forward-looking statements may be identified by the use of words such as “anticipate”, “believe”, “expect”, “estimate”, “plan”, “outlook”, and “project” and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These forward-looking statements reflect the current analysis of existing information and are subject to various risks and uncertainties. As a result, caution must be exercised in relying on forward-looking statements. The following factors, among others, could cause actual results to differ materially from those described in these forward-looking statements: (i) our failure to meet projected development targets, including as a result of the decisions of governmental authorities or other third parties not within our control; (ii) changes in applicable laws or regulations; (iii) the ability of the Astra to meet its financial and strategic goals, due to, among other things, competition; (iv) the ability of Astra to pursue a growth strategy and manage growth profitability; (v) the possibility

that Astra may be adversely affected by other economic, business, and/or competitive factors; (vi) the effect of the COVID-19 pandemic on Astra and (vii) other risks and uncertainties described discussed from time to time in our other public filings with the Securities and Exchange Commission.

Media Contact:

Kati Dahm

kati@astra.com

Investor Contact:

Dane Lewis

dane@astra.com