Firefly Aerospace on Thursday announced that Northrop Grumman invested $50 million to support the development of its medium launch vehicle (MLV), which now has an official name: Eclipse.
Northrop is codeveloping Eclipse with Firefly—which provides the first stage of its Antares 300 family of medium-lift launch vehicles—to fill niches such as national security and space station resupply. Built with components seen on Antares and Firefly’s less powerful Alpha, Eclipse promises to launch nearly 36,000 pounds of payload to low-Earth orbit (LEO).
Firefly anticipates Eclipse’s debut launch from Wallops Flight Facility (KWAL) in Virginia as soon as 2026.
Eclipse’s payload dwarfs that of Alpha, which is capped at around 2,200 pounds to LEO. By comparison, SpaceX’s workhorse Falcon 9—which accounted for more than half of all global launch attempts in 2024—can haul more than 50,000 pounds. Some satellites, though, are too small to justify booking an entire Falcon 9, and Firefly aims to offer a cheaper alternative.
“Eclipse gives customers the right balance between payload capacity and affordability,” said Wendy Williams, vice president and general manager for launch and missile defense systems at Northrop Grumman, in remarks accompanying the announcement.
Per Firefly, Eclipse provides a “significant leap in power, performance, production cadence, and payload capacity” compared to Alpha. The vehicle uses the same first stage it builds for Antares, as well as that model’s avionics. It also features “scaled-up versions” of Alpha’s propulsion systems and composite structures.
The vehicle’s first-stage Miranda and second-stage Vera engines mimic the power cycle of Alpha’s Reaver and Lightning. Firefly said it has performed more than 60 Miranda hot fire tests, including one lasting 206 seconds—the amount of time the engine will need to burn during flight. It has also built hardware for Eclipse’s common dome propellant tanks, engine bay, and interstage.
The company aims to eventually make both Eclipse stages fully reusable, like Falcon 9, to reduce the time and cost to launch.
Firefly hopes to fly the medium-lift vehicle next year. Alpha so far has struggled to get off the ground, suffering partial or total failures on four out of six launch attempts—including the most recent one in April.
The company has had more success with its Blue Ghost lunar lander, which in March became the first commercially built lander to touch down intact on the moon. Blue Ghost spent about two weeks on the lunar surface and deployed an array of science instruments for NASA.
If Firefly can stick to its timeline, Eclipse could find a customer in the U.S. government.
“With a 16 metric ton to orbit capability, Eclipse is a sweet spot for programs like [National Security Space Launch] Lane 1 and a natural fit to launch proliferated constellations in LEO, [medium Earth orbit], [geostationary orbit], and [trans-lunar injection],” said Jason Kim, CEO of Firefly.
Kim is referring to Lane 1 of the U.S. Space Force’s NSSL Phase 3, which aims to launch 30 missions between this year and 2029. Compared to Phase 3 Lane 2, the program has more lenient requirements that are intended to attract newer launch providers. In March, Firefly competitors Rocket Lab and Stoke Space joined Lane 1, which also includes SpaceX, Blue Origin, and United Launch Alliance.
The Space Force has already shown interest in Alpha, which launched its first mission for the branch in 2023. The vehicle is on tap to support a second Space Force mission later this year and in February was selected to launch a third.
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