When American astronauts Butch Wilmore and Suni Williams lifted off on a Starliner test mission to the International Space Station on 5 June, they were expecting to be back home in just 8 days. The mission went fairly smoothly through docking. Then the Boeing Starliner they flew on had an issue. And another. Boeing is expressing confidence in its spacecraft but NASA is divided. A decision is expected next week. Where does that leave the astronauts?

The two were test-driving Boeing’s newest spaceship, the Starliner. All they had to do was put it through its paces, dock briefly with the International Space Station (ISS), then return home. The entire mission was supposed to last around a week. Instead, a series of leaks and malfunctions have caused NASA to indefinitely delay their return.

Just don’t say they’re stranded.

“We’re not stuck on ISS,” Mark Nappi, Boeing’s vice president for its Commercial Crew Program, told reporters in a news conference on June 28. “The crew is not in any danger and there’s no increased risk when we decide to bring Suni and Butch back to Earth.”

NASA has stressed from the first days that in an emergency at the space station — like a fire or decompression — Starliner could still be used by the pair as a lifeboat to leave. For now they can work on the Starliner, or wait and bring them back next year with an already scheduled SpaceX. mission. If that happens, NASA would send only two instead of four astronauts from the next SpaceX taxi flight in late September, with the vacant seats set aside for Wilmore and Williams on the return trip next February (2025).

Wilmore and Williams are both retired Navy captains and longtime NASA astronauts who already have long space station missions behind them. Wilmore, 61, and Williams, 58, said going into this test flight that they expected to learn a lot about Starliner and how it operates. At their only news conference from space in July, they assured reporters they were keeping busy, helping with repairs and research, and expressed confidence in all the Starliner testing going on behind the scenes.

The development of Starliner has not gone smoothly, with NASA requiring an extra uncrewed launch to test issues with clocks and thrusters. Then with parachutes and wiring. The June launch had issues with valves. There are more thruster issues now.

Laura Forczyk with Astralytical, a space consulting group, says: “the problems with the helium system and the thrusters are located in Starliner’s service module, a section of the spacecraft that will be jettisoned before landing.” The engineers may want to keep Starliner at the station longer, so they can gather more data from the module before it burns up during reentry.

As far as supplies, the ISS has a water recycling system and oxygen-generation for the crew. A robotic supply ship arrived this week with fresh clothes, along with extra food and science experiments for the entire nine-person crew.

NASA intentionally hired two companies to get its crews to and from the space station, just as it did for delivering cargo. (The cargo companies are Nortrup Grumman, SpaceX, and SIerra Space). The space agency considers it an insurance policy of sorts: If one crew or cargo provider was grounded, the other could carry the load. ‘You want to have another alternative both for cost reasons and for safety reasons and options. So NASA needs Boeing to be successful,” said Scott Hubbard, who served on the Columbia Accident Investigation Board in 2003.

The goal is to send up one Dragon and one Starliner every year with crews, six months apart, until the station is retired in 2030. At least that much help will be needed for the successor to the ISS, still in planning.

Other alternatives for returning the two include an extra Soyuz or SpaceX mission, but no one is suggesting that. They may be staying for a while, but there are several ways to bring everyone home safe.