Firefly Aerospace vs. Rocket Lab USA: Which Space Stock Is a Better Buy in 2026?

The commercial space race is shifting into a high-stakes operational phase as satellite demand reaches new heights. Firefly Aerospace (NASDAQ:FLY) and Rocket Lab USA (NASDAQ:RKLB) offer two unique ways to play this trend.

While both companies focus on orbital access, they are carving out different niches in the expanding space economy. Firefly is prioritizing rapid launch cycles and lunar services, while Rocket Lab is building a vertically integrated empire that includes satellite manufacturing and global communications.

The case for Firefly Aerospace

Firefly Aerospace provides launch services, lunar landers, and orbital vehicles for government and commercial customers. A primary component of its strategy is developing the Eclipse launch vehicle through an exclusive partnership with Northrop Grumman (NYSE:NOC). This collaboration aims to provide a domestic alternative for medium-lift missions. Customer concentration like this adds a layer of risk to the business, as the top five customers account for over 86% of revenue.

In FY 2025, revenue was $159.9 million, representing a significant increase of approximately 135% compared to the prior year. Despite this rapid growth, the company reported a net loss of about $334 million. Firefly continues to expand its mission profile among defense stocks as it scales its launch operations.

The current debt-to-equity ratio is 0.05%, which is total debt divided by shareholder equity. Free cash flow for FY 2025 was negative $237.8 million. This figure is calculated as cash flow from operations minus capital expenditures.

The case for Rocket Lab USA

Rocket Lab USA operates as an end-to-end space company providing launch services and satellite components. A major expansion occurred with the June 2026 announcement of its $8 billion acquisition of Iridium Communications (NASDAQ:IRDM). This move grants the company access to advanced satellite operations and proprietary L-Band spectrum. The company serves a diverse group of clients, including the U.S. Department of Defense, NASA, and commercial partners like Blacksky Technology (NYSE:BKSY).

For FY 2025, revenue reached $601.8 million, a 38% increase over the previous year. The company reported a net loss of nearly $198.2 million during this period. These figures indicate that while revenue is growing, the company remains in a phase of significant net losses.

The current debt-to-equity ratio is approximately 0.06x. This measures total debt relative to shareholder equity to show how much a company relies on borrowing. Free cash flow reached nearly negative $321.8 million in FY 2025. This metric represents cash flow from operations minus capital expenditures.

Risk profile comparison

Firefly Aerospace faces intense customer concentration, with the majority of its revenue tied to just five major clients. Any contract cancellations or defaults from these partners could significantly impact the company's financial health. Operational reliability is also a concern, as seen with the flight anomaly during the April 2025 Alpha launch. Furthermore, the company must successfully integrate its recent acquisitions to manage the increasing complexity of its services.

Rocket Lab faces substantial execution risk following its multi-billion-dollar acquisition of Iridium Communications. Integrating such a large entity could strain management resources and liquidity while potentially distracting from its core launch business. The company also remains heavily dependent on its Electron rocket, meaning any flight anomalies could pause revenue. Additionally, the strategic vision is closely tied to founder Peter Beck, making his leadership a key risk factor.

Valuation comparison

Firefly Aerospace is cheaper based on its P/S ratio, which measures sales. Neither business is expected to post a profit for fiscal 2026, so there is no forward price-to-earnings ratio to consider.

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Valuation metrics sourced from Financial Modeling Prep (FMP) and may differ from other data providers.

Which stock would I buy in 2026?

Firefly went public in an initial public offering last August at $45 a share. Shares have spent much of the past year below that mark, reflecting typical post-IPO volatility.

More important is the company’s recent business success. Firefly Aerospace is the only private company to execute a successful lunar landing, achieving this in March 2025 with its Blue Ghost Mission I. The success of that effort has ingratiated Firefly with NASA, which sent 10 payloads to the Moon with last year’s mission. The company now plans annual missions to the Moon to deliver payloads for NASA as part of the agency’s aim to construct a permanent lunar base. Exciting stuff, and considering the attention the recent SpaceX IPO - Space Exploration Technologies Inc (NASDAQ:SPCX) — will bring to space businesses, that can only be another positive for FLY.

While future projections are inherently speculative, Wall Street analysts expect Firefly to top $440 million this year and reach $1 billion in annual revenue in its fiscal 2028.

Investing in a young company like Firefly Aerospace will likely bring some turbulence, but it offers rapid growth potential for those going along for the ride.

Rocket Lab, meanwhile, just made a huge splash in the market with its proposed $8 billion acquisition of Iridium Communications. The combination promises to make Rocket Lab a space powerhouse, combining Rocket Lab’s launch technology and the communications spectrum offered by Iridium. In short, Rocket Lab could very well be SpaceX’s serious competitor. Don’t overlook Rocket Lab’s expertise in sending small payloads into orbit, and it is closing in on the same reusable rocket technology that SpaceX has used to lower its customer prices. Stand-alone Rocket Lab is seen boosting its revenue by about 33% this year and narrowing its net loss to about $145 milion. The Iridium acquisition is a big meal to swallow, but the combined business should generate $1.8 billion in revenue in 2026 and come close to breaking even, profit-wise. That gives the business a price-to-sales ratio of around 33, compared with SpaceX’s 115. Firefly is cheaper than both, with a price-to-sales ratio of 26.2 times.

Both Firefly Aerospace and Rocket Lab are exciting space companies that promise significant growth. Rocket Lab’s audacious gambit to take on SpaceX makes it the pick for 2026.

Brendan Coffey has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends BlackSky Technology, Firefly Aerospace, and Rocket Lab. The Motley Fool has a disclosure policy.