Europe’s reusable Prometheus rocket engine ran several hot-fire tests on October 29, 2026, at the P5 test bench in Lampoldshausen, Germany, using a combustion chamber made with a new additive manufacturing process and reigniting several times without a high-pressure starter. The European Space Agency (ESA) said the tests confirmed that both the upgraded bench and the new production methods work.

In an article published on November 6, 2026, ESA said the reignitions relied on engine inlet pressure instead of a high-pressure starter, a first in Europe for an engine of this class. ESA supported the campaign through its Future Launchers Preparatory Programme, with ArianeGroup as prime contractor. ESA owns the P5 bench and the German Aerospace Center (DLR) operates it.

What the October tests proved

The new combustion chamber was made by cold gas spray, an additive manufacturing method in which metal powder travelling at high speed bonds to the chamber body. ESA said the method shortens production time, simplifies complex parts and reduces cost.

Prometheus burns liquid oxygen and methane and is designed to be low-cost and reusable. ESA said it can restart in flight, can be reused across multiple flights and is intended to fit several reusable launcher stages and future European launchers. Its thrust is similar to that of the Vulcain 2.1, the largest European engine in use, which powers Ariane 6. According to ESA, using methane fuel lowers engine and launcher design costs.

A test stand rebuilt for methane

P5 is one of Europe’s largest cryogenic propulsion test facilities. ESA said it was built for the Ariane 5 development programme and has qualified the Vulcain engines and the complete Ariane 6 upper stage. DLR’s own project page describes P5 as ESA’s largest test facility, operated by the DLR Institute at Lampoldshausen.

For Prometheus, the bench was upgraded to run liquid methane, and Prometheus was the first engine fired there on liquid oxygen and liquid methane. ESA said the upgrade can be reversed quickly to supply oxygen and hydrogen, so P5 can still test liquid hydrogen engines. DLR says the converted stand will support quick switching between fuel combinations, including liquid oxygen with liquid hydrogen and liquid oxygen with methane.

Where Prometheus stands

DLR describes the ESA Prometheus programme as the development of a demonstrator for a reusable engine in the “100 tonnes thrust class,” with modulated thrust. A 120-tonne-thrust version running on liquid oxygen and liquid hydrogen is being developed in parallel to test hydrogen-related technology, according to DLR. ArianeGroup manufactures the engine. DLR lists APP of the Netherlands, AVIO of Italy, GKN Aerospace of Sweden and Safran Aero Booster of Belgium as industrial partners, and says the French space agency CNES, which started the programme with ArianeGroup, provides technical support to ESA.

The engine’s earlier test history ran through ArianeGroup’s facility in Vernon, France. In October 2023, ESA reported that an early prototype had achieved first ignition there in June 2023, followed on October 20, 2023, by a 30-second firing with re-ignition. At the time, ESA said new materials and manufacturing techniques were expected to bring costs to a tenth of those of Ariane 5’s Vulcain 2, and that ArianeGroup planned to install a prototype on a test bed modified for liquid methane at DLR’s Lampoldshausen site.

Prometheus has also been tested mounted in Themis, an early prototype reusable stage developed in parallel under an ESA contract. ESA said in 2023 that a more advanced Themis prototype was being prepared for “hop-tests” in Kiruna, Sweden, aiming to lift off and rise as high as 100 m to check flight and landing capability. AirPro News covered the assembly of the Themis demonstrator as part of Europe’s push for reusable launchers.

ESA did not give a date for the next Prometheus test series in its November 6 article. DLR says its Lampoldshausen site will conduct the Prometheus test campaigns on P5, and it also lists a related demonstrator, the ETID engine model, for a liquid oxygen and methane upper-stage engine with 100 kilonewtons of thrust intended for future heavy-lift rockets.

Firefly Aerospace will deliver 36 rocket engines to AST SpaceMobile, license it to build them and provide three years of engineering support under a deal valued at more than $1.3 billion, the two Texas companies announced on November 6, 2026. The engines will power Blacklift, a rocket designed for reuse that AST SpaceMobile plans to build itself to launch its BlueBird satellites from late 2028.

In a press release dated November 6, 2026, Firefly said it will supply 27 Miranda engines and nine vacuum-variant Vira engines for AST SpaceMobile’s first three rockets. AST SpaceMobile, in its own release issued the same day from Midland, Texas, described Blacklift as a 20-ton rocket designed for reusability and able to carry up to five BlueBird satellites per launch. The Miranda and Vira engines were developed for Eclipse, the medium launch vehicle Firefly is co-developing with Northrop Grumman, and that rocket’s first launch is listed for no earlier than 2027.

How the payments are structured

AST SpaceMobile’s release splits the agreement in two. Under the license agreement, it will pay approximately $800 million in upfront consideration, made up of $400 million in cash and 10 to 14 million shares of Class A Common Stock, with the share count set by a forward volume-weighted average price (VWAP) calculation. Under a separate supply and services agreement, it will pay $250 million for engines for its first three rocket launches and $250 million over three years for engineering support services.

Firefly’s release states that the stock it receives is subject to lock-up periods. Firefly keeps full ownership of its engine intellectual property and will continue to serve the government and commercial launch market, and the company described the agreement as non-competitive by design. AST SpaceMobile said it will produce the engines at a new engine manufacturing facility in the United States; neither release gives its location.

Jason Kim, CEO of Firefly Aerospace, said in both companies’ releases:

“This is a bold transformational deal for Firefly, for AST SpaceMobile, and for the space industry.”

He added that the engine is the hardest and highest-stakes decision a company makes when it sets out to build its own rocket.

The engines behind the deal

According to Firefly, the Miranda engine has completed more than 175 hot fire tests totaling over 4,200 seconds. In a flight-like test at 110% of its 230,000 lbf thrust, the engine ran 20 seconds beyond the nominal 206-second flight duration. AST SpaceMobile’s release puts the accumulated test time at the equivalent of approximately 20 full first stage flights.

Both engines are scaled from the Reaver and Lightning engines that power Firefly’s Alpha rocket and use the same patented tap-off cycle. On Eclipse, seven Miranda engines power the first stage and one Vira engine powers the second stage, according to Firefly’s Eclipse web page, which lists a payload of 16,300 kg to low Earth orbit and a first stage designed for propulsive landing and reuse.

The test record has grown quickly. When Northrop Grumman announced its $50 million Eclipse investment on May 29, 2025, and the vehicle received the Eclipse name, more than 60 Miranda hot fire tests had been performed. In its second quarter 2026 results on August 11, 2026, Firefly reported that it had crossed 150 hot fire tests, including a flight-like Mission Duty Cycle run of 226 seconds.

Where Eclipse and AST SpaceMobile’s launch plans stand

The May 2025 release said Eclipse would first launch from Wallops Island, Virginia, as early as 2026. Firefly’s Eclipse page now lists the first launch from Virginia’s Mid-Atlantic Regional Spaceport (MARS) no earlier than 2027.

AST SpaceMobile, which describes itself as building the first and only space-based cellular broadband network accessible directly by everyday smartphones, assembles its BlueBird spacecraft in Midland, Texas. Each BlueBird array measures approximately 2,400 square feet (223 square meters). The company said Blacklift completes its long-held strategy of end-to-end vertical integration and supplements its existing launch arrangements: it will continue to use external providers, with agreements covering over 100 BlueBird satellites to be deployed cumulatively between 2027 and 2028. It also has access to further launches for US Government missions under its Defense Priorities and Allocations System (DPAS) rated program.

Abel Avellan, Founder, Chairman and CEO of AST SpaceMobile, said in Firefly’s release that “Firefly is one of a few companies in the United States with a proven liquid engine of this scale.” Scott Wisniewski, President of AST SpaceMobile, said the Miranda engine “will allow us to leapfrog the traditional five-to-ten-year development cycle as we build Blacklift.”

What Firefly plans to do with the funds

Firefly said it will use the proceeds to expand hiring, buy long-lead materials, acquire equipment and upgrade infrastructure, including multiple new test bays at its Rocket Ranch in Briggs, Texas. The company said the steps are meant to increase launch vehicle production and testing and bring forward milestones across its core programs. “The agreement supercharges Firefly’s production system,” Kim said.

The deal arrives as Firefly’s revenue grows. The company reported record second quarter 2026 revenue of $117.7 million, up 45.5% from the prior quarter, and said it expects 2026 full-year revenue of between $420 million and $450 million. Its second quarter results also listed an extension of its Lockheed Martin Alpha agreement to up to 25 Alpha launches through 2031.

AirPro News analysis

The agreement gives Firefly an outside customer for engines developed for a rocket whose first launch is listed for no earlier than 2027, with the license portion paid upfront in cash and stock. Firefly says the money will expand production and testing across its launch portfolio, which includes Eclipse. For AST SpaceMobile, Blacklift is an addition to, not a replacement for, external launch agreements covering over 100 BlueBird satellites in 2027 and 2028. Firefly supplies the engines for the first three rockets; beyond those, AST SpaceMobile holds a license to build its own at a new US facility whose location has not been disclosed.

What comes next

Firefly will discuss the agreement on its Third Quarter 2026 Earnings call at 5 p.m. ET on Tuesday, November 10, 2026. AST SpaceMobile will hold an unveiling event for the Blacklift rocket on Thursday, November 12, 2026, in New York City, with a webcast on its Investor Relations website.

The Federal Aviation Administration (FAA) on November 5, 2026, proposed three changes to its Part 450 commercial launch and reentry rules that would clarify when an operator must abort a flight and add a new way to show public protection when a vehicle makes an uncontrolled return from orbit. The agency also issued a final rule of technical corrections and said a broader overhaul of its licensing framework will begin in 2027.

Transportation Secretary Sean P. Duffy announced the package in an FAA release dated November 5, 2026, together with a hiring drive for the FAA Office of Commercial Space Transportation. Public comments on five earlier Part 450 proposals, announced by the U.S. Department of Transportation (USDOT) on October 6, 2026, closed on November 4, 2026.

What the three proposals would change

Ending flight abort by phase of flight

The first proposal (RIN 2120-AM37, docket FAA-2026-9943) revises § 450.108(e). As currently written, that paragraph says an operator using flight abort as a hazard control strategy “is not required to initiate flight abort to protect against high consequence events” once certain conditions are met, and those conditions apply to the remainder of the flight.

The FAA would instead apply the exception “to a phase of flight in which the conditions are present,” so an operator could turn flight abort off in one phase and back on in a later one. The paragraph’s heading would change from “End of flight abort” to “End of flight safety limits.” The agency stressed that the paragraph “does not require an operator to turn off flight abort capability” and said the change adds no costs, while “there may be minimal cost savings.”

One calculation for flight safety limits

The second proposal (RIN 2120-AM43, docket FAA-2026-9937) rewrites § 450.108(c)(4), which requires flight safety limits that prevent conditional expected casualties (CEC) “greater than 1 × 10−2 in uncontrolled areas.” The FAA said the current wording has led applicants to misread whether two separate calculations are needed.

Under the proposal, CEC would be “averaged over outcomes that result in either flight abort or flight outside the limits of a useful mission,” with the threshold unchanged. The FAA expects 40 new license applications over five years and describes the savings as “minimal.”

Vehicle breakup during uncontrolled reentry

The third proposal (RIN 2120-AM33, docket FAA-2026-9942) adds an option to § 450.101(c)(2). Operators must currently protect against high consequence events through flight abort, by keeping risk below a threshold of “1 × 10−3 conditional expected casualties,” or through demonstrated reliability. The new option would let an applicant show “sufficient breakup of the launch or reentry vehicle” during an uncontrolled atmospheric return, including all vehicle components and undeployed payloads.

The FAA would define that event as “the passive descent of a launch or reentry vehicle from orbit that occurs as a result of natural orbital decay.” Applicants would rely on data already required under §§ 450.121 and 450.135(b), so no new analysis would be needed. The agency estimates each applicant would save about 60 hours of aerospace engineer labor, or $5,777 per application, and puts total savings at $9,674 per application.

All three notices were issued by Anh Minh Ngoc Nguyen, Deputy Associate Administrator of the Office of Commercial Space Transportation. The final rule, identified as 2120-AM32, applies minor technical corrections across the commercial space rules.

How the November package builds on October’s proposals

USDOT announced the first five proposals on October 6, 2026, after their publication in the Federal Register on October 5, 2026. They would let operators submit launch applications electronically, combine three required safety analyses into a single submission and drop duplicative analyses where another approved method already meets a requirement. Both sets of proposals amend the FAA’s Part 450 licensing rule.

The October proposals were developed with the USDOT Space Policy Administration, Coordination, and Execution (SPACE) Task Force, and the FAA said the November actions align with the Enabling Competition in the Commercial Space Industry order, covered in the 2025 commercial space executive order. The FAA also pointed to its proposed rule to waive environmental laws and regulations it described as unnecessary, the subject of the FAA’s environmental waiver proposal.

The FAA said the U.S. was responsible for 217 of the 329 commercial space launches worldwide in 2025. USDOT expects 10,000 FAA-licensed launches and reentries per year by 2035, and the FAA said its 2027 overhaul is meant to support an anticipated 1,000 launches per year by 2030.

What comes next for operators and the FAA

The Office of Commercial Space Transportation is adding an Associate Administrator and a new team of aerospace engineers for safety analysis, evaluations and mission authorizations, which USDOT said is intended to speed application turnaround. The FAA is also seeking public and industry input on where to build new spaceports and on creating “priority airspace” for space launch routes.

Under Secretary for Transportation Ryan McCormack said in the FAA release, “We’re leaving no stone unturned to safely reform licensing and environmental regulations.” Duffy described the aim as “unleashing American space dominance while never compromising on safety.”

AirPro News analysis

By the FAA’s own estimates, these three proposals are clarifications with modest savings: about 60 engineering hours and $9,674 per application for the reentry option, and savings the agency calls “minimal” for the two flight abort changes. For launch operators, the practical gain is less ambiguity in how flight safety limits are calculated and more freedom to manage flight abort by phase of flight. The larger structural change the agency has announced is the licensing overhaul it plans to begin in 2027.