(NewsNation) — As NASA ponders how to bring home two Boeing Starliner astronauts who remain on the International Space Station, they are just fine aboard the ISS, a former astronaut tells NewsNation.

“I sort of resisted the idea that they were stranded. Coming back home safely is not an issue. It’s how they’re doing it,” said former astronaut Jose Hernandez.

Butch Wilmore and Suni Williams have been on the ISS since early June on what was planned to be an eight-day mission. But the problems with their Starliner spacecraft began even before they lifted off on June 5.

Their capsule sprang a leak in propulsion-related plumbing. Boeing and NASA judged the small helium leak to be stable and isolated and proceeded with the test flight. But as Starliner approached the space station the next day, four more leaks erupted. Five thrusters also failed. The capsule managed to dock safely, and four of the thrusters ultimately worked.

While flight managers have yet to find the root cause for the thruster malfunctions, all but one of the 28 thrusters seem fine right now. But the fear is that if too many conk out again, the crew’s safety could be jeopardized. The thrusters are needed at the flight’s end to keep the capsule in the right position for the critical deorbit burn.

So, they wait. But, as Hernandez said, not “stranded.” NASA has also pushed back at suggestions that Wilmore and Williams are stranded or stuck. NASA has said since June 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.

A former NASA executive said Thursday the astronauts are “kind of stuck,” although certainly not stranded. A recent resupply mission brought Wilmore and Williams some clothes of their own and more than enough supplies for them and the seven others aboard the ISS.

“Having two extra mouths to feed and two extra lungs to breathe air: they have enough consumables to take care of that,” said Hernandez. He adds that there is plenty to keep the extra crew members busy, and they have adjusted their daily routines to stay fit in space.

“The only thing that changes is their exercise protocol,” said Hernandez. “They have to exercise (for) about an hour and a half just to keep their muscles toned and bones density up.”

Meanwhile, the current schedule of supply and crew missions to the ISS must be re-configured to find two empty seats for Wilmore and Williams.

Like Boeing’s Starliner, SpaceX’s Dragon is meant to carry four astronauts. To make room for Wilmore and Williams, NASA said Wednesday it could bump two of the four astronauts due to launch to the space station next month with SpaceX.

The empty seats would be reserved for Wilmore and Williams, but they would have to remain up there until February. That’s because station missions are supposed to last at least six months. Some have lasted a year.

So why are there two companies, Boeing and SpaceX, in the astronaut shuttle business? NASA deliberately hired two companies to get its crews to and from the space station, just as it did for delivering cargo. The space agency considered 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, a former NASA director who currently serves on the Safety Advisory Panel for SpaceX.

The Associated Press contributed to this report