Astronauts Butch Wilmore and Suni Williams traveled to the space station aboard the Starliner back in June. Their trip was initially only to last about eight to 10 days, but multiple issues with the Starliner prompted a concerned NASA, out of caution, to leave them behind at the space station and return the capsule to Earth empty in September. That same month, a SpaceX Crew-9 Dragon capsule with a reduced two-person crew and two empty seats launched to the space station with the intention of returning Wilmore and Williams aboard it in February 2025. However, NASA said in a news release Tuesday that Wilmore and Williams' replacements, traveling aboard the SpaceX Crew-10, would be launching to the space station "no earlier than late March 2025," meaning that would be the earliest that Wilmore and Williams will return to Earth. The most recent delay in the Crew-10's launch is to give "NASA and SpaceX teams time to complete processing on a new Dragon spacecraft for the mission." NASA astronauts Butch Wilmore and Suni Williams, seen ahead of their launch on Boeing's Starliner spacecraft, in Cape Canaveral, Florida, June 5, 2024. Getty Images The Crew-9 — carrying Williams, Wilmore, fellow NASA astronaut Nick Hague and cosmonaut Aleksandr Gorbunov — can only leave the space station following a "handover period" with the Crew-10. The handover period "allows Crew-9 to share any lessons learned with the newly arrived crew and support a better transition for ongoing science and maintenance at the complex." NASA did not speculate on how long that handover might take. The Starliner, Boeing's answer to the Crew Dragon, has faced major headwinds since it went into development, including a series of technical issues and budget shortfalls. It finally launched, but after arriving at the space station with its crew, multiple helium leaks were discovered in the Starliner's propulsion system, along with a degraded thrust in five of its maneuvering jets. A return in late March or April would mean that a trip that was expected to last just over a week for Williams and Wilmore will have been stretched to at least nine months. "Fabrication, assembly, testing, and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail," Steve Stich, manager for NASA's Commercial Crew Program, said in a statement Tuesday about the Crew-10. "We appreciate the hard work by the SpaceX team to expand the Dragon fleet in support of our missions and the flexibility of the station program and expedition crews as we work together to complete the new capsule's readiness for flight."