Firefly Aerospace Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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LETTER FROM OUR CHIEF EXECUTIVE OFFICER

Dear Firefly Stockholders,

Firefly is coming off a transformative year in our history: We nailed the first and only successful commercial Moon landing, completed a historic IPO, and acquired SciTec, further bolstering our national security contributions alongside defense contract wins for our Elytra orbiter and Alpha vehicle. We’ve entered a new era as an end-to-end space and defense business, executing milestones across our programs, in just our ninth year as a company.

We are delivering innovative hardware and software to perform the hardest missions in space for national security, exploration, and commercial customers.

We bolstered our four-revenue generating hardware products – the operational 1-ton Alpha rocket, the reusable Eclipse rocket, the mission proven Blue Ghost lander, and the Elytra satellite orbiter – with SciTec’s AI-enabled defense software proven in operations, such as missile warning and defense. The industry tailwinds behind artificial intelligence and data centers are fueling operational realities for SciTec, which is delivering crucial no-fail systems in support of U.S. national security initiatives.

We are meeting the U.S. government’s call for commercial investment and scale in the defense sector, with multiple opportunities to support the Pentagon’s Golden Dome initiative. We are further developing our advanced technology products, while funding infrastructure upgrades and expansion of Firefly’s spacecraft and rocket factories, as well as SciTec’s data server centers and classified facilities.

Firefly’s product suite is strategically tailored to support the growing opportunities in the space sector. In particular, the renewed interest in the Moon as a top priority is an outstanding confirmation of Firefly’s market position, accelerating with contracts for additional landings in the years ahead.

We applaud NASA’s ramp up of the Artemis program to build a Moon Base – as we’re eager to test and refine the technologies needed to sustain a permanent lunar presence. We’ve made progress on expanding our spacecraft clean room, to better enable us to build multiple landers simultaneously.

Firefly remains focused on our mission of repeatedly and reliably launching, landing and operating space systems from Earth, to the Moon and beyond. Thank you for joining us in our journey, as we light the way to a bold space ecosystem that expands humanity’s future.

Jason Kim

Chief Executive Officer

NOTICE OF 2026 ANNUAL MEETING OF STOCKHOLDERS

Leander, Texas 78641

Dear Fellow Stockholders,

The 2026 Annual Meeting of Stockholders of Firefly Aerospace Inc. (the “Annual Meeting”) will be conducted virtually, via live audio webcast, at www.proxydocs.com/FLY on June 4, 2026, at 8:30 a.m. Central Time for the following purposes:

to elect the two nominees identified in the accompanying proxy statement to our Board of Directors (the “Board”);

to ratify the appointment of Grant Thornton LLP as our independent registered public accounting firm for the year ending December 31, 2026; and

to transact other business as may properly come before the meeting or any adjournment, postponement or continuation of the meeting.

These items of business are more fully described in the proxy statement accompanying this letter.

The record date for the Annual Meeting is April 7, 2026. Only stockholders of record of our common stock at the close of business on the record date may vote at the Annual Meeting. For registered stockholders, to vote at the Annual Meeting, you will need the 12-digit control number included on your Notice of Internet Availability of Proxy Materials (the “Notice”) or proxy card. If you are a street name stockholder, unless your voting instruction form or Notice indicates that may vote your shares through theproxyvote.com website, you will need to obtain a legal proxy from your broker, bank, or other nominee in order to vote your shares at the Annual Meeting.

A list of stockholders entitled to vote at the meeting will be available for examination by any stockholder for any purpose germane to the meeting during ordinary business hours for a period of at least ten (10) days prior to June 4, 2026, at our principal executive offices at 2203 Scottsdale Drive, Leander, Texas 78641.

Whether or not you plan to attend the Annual Meeting, we urge you to submit your proxy or voting instructions via the Internet, telephone, or mail as soon as possible.

By Order of the Board of Directors,

David Wheeler

SVP, General Counsel

Cedar Park, Texas

April 17, 2026

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON JUNE 4, 2026:This Notice of Annual Meeting, the accompanying proxy statement and our Annual Report on Form 10-K for the Fiscal Year Ended December 31, 2025 are available at www.proxydocs.com/FLY.

TABLE OF CONTENTS

The Board of Directors (the “Board”) of Firefly Aerospace Inc. (“Firefly,” the “Company,” “we,” “us” or “our”) is soliciting your proxy to vote at the 2026 Annual Meeting of Stockholders to be held on June 4, 2026, at 8:30 a.m. (CT) via live audio webcast atwww.proxydocs.com/FLY (the “Annual Meeting”). This proxy statement (this “Proxy Statement”) is dated as of April 17, 2026 and is first being sent to our stockholders of record on or about April 17, 2026.

Note About Forward-Looking Statements

This document includes forward-looking statements within the meaning of the federal securities laws. All statements other than statements of historical or current facts made in this document are forward-looking. We use words such as “anticipate,” “accelerate,” “be,” “believe,” “enable,” “may,” “will,” “should,” “could,” “estimate,” “continue,” “expect,” “future,” “intend,” “target,” “project,” “plan,” “contemplate,” “predict” and similar expressions to identify forward-looking statements. Forward-looking statements reflect management’s current expectations and are inherently uncertain. Actual results could differ materially for a variety of reasons. Risks and uncertainties that could cause our actual results to differ significantly from management’s expectations are described in our Annual Report on Form 10-K for the year ended December 31, 2025. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements we make.

Note About Our Website and Reports

None of the statements on our website, other websites, or the current or periodic reports referenced or discussed in this proxy statement, are deemed to be part of, or incorporated by reference into, this proxy statement. Some of the statements on our website, other websites, or the current or periodic reports herein, may contain cautionary statements regarding forward-looking information that should be carefully considered. The statements on our website, other websites or other current or periodic reports may also change at any time and we undertake no obligation to update them, except as required by law.