Could a spacecraft that left astronauts stranded for almost nine months really be trusted to fly again in just over a year? NASA and Boeing think so-though this time, the ride will be strictly cargo.
NASA has now confirmed that Boeing’s next CST-100 Starliner flight will fly no sooner than April 2026, targeted as Starliner-1. That mission will bring supplies to the International Space Station while performing in-flight validation of system upgrades made in the aftermath of the troubled 2024 Crew Flight Test. That test had been intended as the crewed debut of Starliner; it became a high-profile failure marred by helium leaks and propulsion system malfunctions that forced NASA to bring its astronauts home aboard a SpaceX Dragon capsule.
The contract underpinning Starliner’s role in NASA’s Commercial Crew Program has also been reshaped. Originally awarding Boeing six guaranteed crew rotation flights to the ISS, NASA has now cut that number to four, with two additional missions now optional. According to agency figures, the change trims the contract’s value by $768 million to $3.732 billion, reflecting the program’s delayed progress compared to SpaceX’s Crew Dragon, which has flown 12 crewed missions since 2020.
The 2024 Crew Flight Test launched from Kennedy Space Center atop a United Launch Alliance Atlas V rocket carrying astronauts Butch Wilmore and Sunita Williams. Planned as a 10-day mission, it was extended dramatically when multiple thrusters in Starliner’s propulsion system shut down during approach to the ISS. Engineers also detected five helium leaks in the service module manifolds. NASA ultimately judged the spacecraft unsafe for crew return, ordering it to undock empty in September 2024 for a parachute-assisted landing in New Mexico. Wilmore and Williams remained on board the station until March 2025, logging 286 days in orbit before returning on SpaceX’s Crew-9 mission.
The next cargo flight is more than a logistics run; it is a critical test of Starliner’s redesigned propulsion system. NASA and its contractor have begun an extensive series of ground tests, including hot-fire tests at White Sands Test Facility capable of duplicating flight-like pulse counts and thermal conditions. The engineers are looking at helium leak rates, operational mitigations, and are reviewing contingency thruster combinations to make certain that the thrusters can perform safely on the spacecraft during undocking, deorbiting and landing. Notably, test results recently showed better-than-expected performance by the instrumentation for the thrusters, ruling out overheating of pressure transducers as the cause of why thrusters shut off early. Why these tests matter was underlined by the latest report from the Aerospace Safety Advisory Panel.
In addition to the service module failures, the panel disclosed that a monopropellant thruster in the crew module of Starliner also failed on its way back to Earth-an issue unrelated to those previously reported. “Had the crew been aboard, this would have significantly increased the risk during reentry, confirming the wisdom of the decision,” the report added.
The panel further expressed concerns about ambiguity in risk management roles and responsibilities between Boeing and NASA in the course of the resolution of anomalies and called for clear contractual and programmatic direction to avoid conflicts of interest. If Starliner-1 flies nominally, Boeing may go ahead with Starliner-2, which could be its first operational crew rotation mission. But astronaut assignments are not yet settled. Several astronauts who were assigned previously to fly on Starliners have since been reassigned to SpaceX missions. Limits on radiation exposure may preclude veteran flyers like Williams from being selected again.
The Starliner certification remains critical for NASA in terms of “dissimilar redundancy” in crew transportation-that it does not depend on SpaceX or Russian Soyuz vehicles exclusively. With the retirement of the ISS coming up in 2030, the time is growing short for Boeing to demonstrate Starliner’s reliability to secure a place for it in the station’s last decade of operation. The April 2026 flight would be a milestone for whether the spacecraft can overcome its troubled history to become, as Dragon has, a trusted ride to low Earth orbit.