Astronauts on Boeing's Starliner have been in space for more than 60 days, and there is no end in sight

(CNN) – Butch Wilmore and Suni Williams, two veteran NASA astronauts who piloted the first crewed test flight of Boeing's Starliner spacecraft, have been in space for 63 days, about seven weeks longer than initially expected.

There is still no clear return date in sight.

As analysis continues to understand the issues Starliner experienced en route to the International Space Station, NASA is exploring several contingency options, the space agency confirmed during a press conference Wednesday. Those contingencies include keeping Williams and Wilmore on the orbiting lab for another six months and bringing them home on a SpaceX Crew Dragon vehicle in 2025.

CNN confirmed Tuesday that NASA has not yet begun a “flight readiness review” for the Starliner crew’s return from the space station. The agency had said on July 26 that it would begin that process in early August.

But Boeing and NASA teams are still working toward a potential return date as officials evaluate test data and conduct analysis on the propulsion issues and helium leaks that hampered the Starliner capsule’s first stage of flight. Ground tests that mission teams conducted in New Mexico as they worked to understand the issues led to surprising results, Steve Stich, NASA’s commercial crew program manager, said Wednesday.

The space agency previously confirmed that it found excess heat around some of Starliner’s thrusters that was causing Teflon seals to bulge, restricting propellant flow and triggering the thruster problems. Uncertainty over whether those bulging seals are in fact the root cause of the problem — and how the issue might affect the Starliner vehicle in space — are at the root of disagreements within NASA over how safe it is for the crew to return on Starliner, officials revealed at the news conference.

The return of the Starliner spacecraft remains uncertain as officials work to reach an agreement on how the rest of the mission launched June 5 should unfold.

“I would say our chances of an uncrewed return on Starliner have increased a little bit based on how things have gone over the last week or two,” said Ken Bowersox, associate administrator for NASA’s Space Operations Mission Directorate, referring to NASA’s internal review processes that must be completed before a return date for Starliner is decided. “But again, new data coming in, new analysis, different discussions, we could find ourselves moving in another direction.”

NASA has always considered the return of Williams and Wilmore on a SpaceX vehicle as a mission contingency, but the ultimate goal is to bring the two astronauts home on Starliner. Boeing argued that their spacecraft is safe for astronauts.

However, the space agency announced Tuesday that it will delay the launch of SpaceX's Crew-9 mission, a routine flight scheduled to fly four astronauts to replace the Crew-8 mission aboard the International Space Station.

Crew-9 had been scheduled to launch on Aug. 18, with the expectation that the Starliner capsule would have returned home with its astronauts before then. Now, Crew-9 will not launch before Sept. 24, NASA said.

“This adjustment allows more time for mission managers to finalize return planning for the agency's Boeing crewed flight test,” NASA said in a statement. press release on Tuesday.