Astronauts Butch Wilmore and Suni Williams inspect safety hardware aboard the ISS in August 2024. NASATwo NASA astronauts who launched on an eight-day mission to the International Space Station (ISS) in June had already seen their intended short stint in orbit stretched into an eight-month odyssey. Now, however, the pairs return home will be postponed even further because of a delay in the arrival of their replacement crew, NASA announced in astatement on Tuesday.Suni Williams and Butch Wilmore arrived at the ISS in early June aboard Boeings Starliner spacecraft in its first crewed test flight. The craft, meant to one day shuttle astronauts back and forth from orbit, experienced helium leaks and thruster failures during its flight. As such, NASA deemed Starliner unfit to return the astronauts to Earth. Starliners capsule Calypso made the journey homecrewless and in autonomous modein September.As its pilots, you dont want to see it go off without you, but thats where we wound up, Wilmore told the Associated Press Marcia Dunn at the time.With Calypso back on Earth, NASA saved Williams and Wilmoreseats on a SpaceX Dragon craft scheduled to return the Crew-9 mission astronauts from the ISS in February. Now, the agency says theyll have to wait until late March at the earliest. The change is due to a delay in the launch of NASAs Crew-10 mission, which was pushed back to allow engineers more processing time for a new Dragon spacecraft. The vehicle is scheduled to arrive at SpaceXs Florida processing facility in January.Fabrication, assembly, testing and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail, Steve Stich, NASAs Commercial Crew Program manager, says in the statement. 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 capsules readiness for flight.The astronauts on Crew-10Anne McClain and Nichole Ayers of NASA, Takuya Onishi of the Japan Aerospace Exploration Agency (JAXA) and Roscosmos cosmonaut Kirill Peskovwill take over operations of the ISS from Crew-9. For a period, both crews will overlap on the station, a process called crewed handover. Upon Crew-10s arrival, Crew-9NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov, in addition to Williams and Wilmorewill share the necessary information to ensure a smooth transition for the ISS, including the ongoing science experiments.NASA has not revealed how long the handover period is expected to last. Even if its brief, by then Williams and Wilmore will have spent nearly nine months aboard the orbital station. But theyve been engaging in crew activities and contributing to maintenance and science.Theres always work to do on the space station. For most of the life of the space station, weve had a backlog of science experiments that we just didnt have enough crews up there to take care of, former NASA astronaut Michael Fossum told the Texas Standards Shelly Brisbin in early September. I have a feeling right now theyre working through that backlog fairly quickly with the larger crew up therewith Butch and Suni.Two resupply missions in November have ensured that the ISS remains well-stocked for its crew, NASA notes in the statement. The flights even brought special items to allow Crew-9 to celebrate the holidays in orbit.Im sure that they are already disappointed that they were going to miss Christmas back home with the folks, Simeon Barber, a planetary science specialistat the Open University, tells the BBCsPallab Ghosh.But this is only another two months on an already quite long mission, and Im sure if you ask them, Im sure they would tell you that the space station is where they love to be.Get the latest stories in your inbox every weekday.Filed Under: Astronauts, NASA, Space Travel, SpaceX, Technology, Transportation