Stranded in the Sunset: ULA’s Last Six Atlas V Rockets Can Only Fly Boeing’s Uncertified Starliner
Featured image: [An Atlas V rocket launching with Boeing’s Starliner capsule mounted on top; credit: United Launch Alliance/NASA]
United Launch Alliance has six Atlas V rockets left in its inventory. Every single one of them is locked to a single mission: launching Boeing’s Starliner crew capsule. And Boeing’s Starliner isn’t certified to carry astronauts yet, and may not be until 2027.
The predicament, detailed by Ars Technica on July 7, reveals a perfect storm of engineering and programmatic constraints that leaves some of the most reliable rockets ever built essentially idle, waiting on a spacecraft that may not need them all.
Why these six can’t fly anything else
The last non-Starliner Atlas V flew on July 2, carrying 29 Amazon Leo satellites on its eighth operational mission for the constellation. That was the 110th flight of the Atlas V since its debut in 2002, a near-flawless career that included national security payloads, NASA science missions, and the launches that built Amazon’s broadband network.
But that was also the last Atlas V to fly with a payload fairing. Starliner mounts exposed, the capsule sits directly on top of the rocket without a fairing. ULA confirmed to Ars that the Vulcan rocket’s fairing is “not interchangeable” with the out-of-production Atlas fairing.
The remaining rockets also have dual-engine upper stages optimized for Starliner’s low-Earth orbit trajectory, and only enough strap-on solid boosters in storage for two per rocket, ruling out the heavy five-booster configuration used for deep-space payloads.
Even if Boeing gave up its launch slots, ULA could not practically repurpose these rockets for other customers.
A legend’s waiting game
Atlas V production ended in 2024, with the final Common Core Booster completed in Decatur, Alabama. The decision to retire the rocket was driven by a congressional mandate to phase out its Russian-made RD-180 engines, a geopolitical vulnerability that spurred ULA’s transition to the new Vulcan Centaur.
But Vulcan has been grounded since February 2026 due to anomalies with its solid rocket boosters, and the catastrophic pad explosion of Blue Origin’s New Glenn in May 2026 casts a shadow over Vulcan’s return-to-flight since both share the BE-4 engine.
Amazon, which relied on Atlas V for the early deployment of its Leo constellation, has 398 production satellites in orbit and 38 Vulcan launches reserved. But with Vulcan grounded and New Glenn destroyed, only Falcon 9 and Ariane 6 are currently available for further Amazon launches.
“We’ve completed enough launches for initial service this year, and future missions just add coverage and capacity,” said Chris Weber, vice president for Amazon Leo, on X.
Starliner’s long road
Boeing’s Starliner program was awarded a $4.2 billion Commercial Crew contract in 2014, nearly double what SpaceX received for Crew Dragon. Eleven years and three flight tests later, Starliner still isn’t certified.
The troubled Crewed Flight Test in June 2024 left astronauts Butch Wilmore and Suni Williams stranded on the ISS for nine months while NASA and Boeing debated whether Starliner was safe to return them. They eventually came home on a SpaceX Crew Dragon in March 2025.
NASA subsequently reduced Boeing’s guaranteed crew missions from six to four. A NASA Office of Inspector General audit published June 30 found Starliner certification is likely delayed to 2027 at the earliest, roughly a decade late.
The next Starliner flight, Starliner-1, is planned as an uncrewed cargo mission that would burn one of the six Atlas Vs. Whether Boeing will need all six rockets, or whether NASA will exercise options for the remaining two, remains an open question.
Meanwhile, SpaceX’s Crew Dragon has been certified since 2020 and has completed over a dozen crewed missions. It remains NASA’s sole operational crew transportation vehicle.