NASA has confirmed it will take time to certify its Starliner spacecraft for human missions due to ongoing propulsion system issues. The agency said the next flight of the vehicle, which could carry astronauts or cargo, is likely to occur late this year or in 2026.
Several tests marred Starliner’s first crewed flight last June, with multiple thrusters failing to function as expected. These issues led to a safe return for astronaut Butch Wilmore and Suni Williams using a Crew Dragon vehicle instead.
A recent test saw the spacecraft autonomously re-enter the Earth’s atmosphere in September. However, data from the test suggests that propulsion system problems persist, despite efforts by NASA engineers to address over 70% of the observed issues.
Source: https://arstechnica.com/space/2025/03/nasa-to-put-starliners-thrusters-through-an-extensive-workout-before-next-launch