Long-distance travelers Butch Wilmore and Suni Williams miss their flight in a different way than ordinary folks. Their trip back from the International Space Station (ISS) is delayed until February 2025. The astronauts, working aboard the orbiting platform since early June, can't fly home when planned because NASA isn't sure a Boeing Starliner spacecraft docked at the ISS is safe enough to bring them to Earth. "There was just too much uncertainty," says Steve Stich, a NASA manager.

So the Starliner will fly back empty, probably this month, and the U.S. space agency will use a four-seat Dragon Capsule to be launched by Elon Musk's SpaceX company on Sept. 24 with two astronauts. After their previously scheduled ISS mission, that pair and the delayed duo will head home about five months from now. Boeing's reusable capsule, plagued by technical issues since its first unmanned orbital test in 2019, had malfunctioning thrusters and a leaking helium tank on its way up in June with Wilmore and Williams aboard. It was the Seattle aviation company's first space launch with passengers.

Wilmore, 61, and his 58-year-old NASA colleague face no extra danger as they wait and work alongside seven fellow astronauts from other nations. An unmanned Russian cargo ship brought nearly three tons of food, water, rocket propellant, nitrogen and other supplies in mid-August. "It's great to be up here, so I'm not complaining," Williams said during a July video news conference. This is her third time at the station. She and Wilmore were scheduled to stay just eight days originally. Still, NASA is sensitive about how news media describe their ahem extended visit. "They're not really stranded," says Lori Garver, a former deputy administrator says.

NASA head says: "The decision to keep Butch and Suni aboard the International Space Station and bring the Boeing Starliner home uncrewed is a result of a commitment to safety." – Bill Nelson, agency administrator

Space contractor says: "If I got stuck at an airport for seven months longer than expected, that would definitely qualify as 'stranded.'" – Delian Asparouhov, president of Varda Space Industries, in tweet

ISS facts: The space station, made of parts assembled in orbit by dozens of past astronauts from five space agencies, travels at a zippy 17,500 mph and orbits roughly 250 miles above Earth on average.