Explained: How Boeing's Starliner Can Bring Astronauts Back To Earth

Starliner can stay docked at the ISS for up to 45 days, according to comments by NASA's commercial crew manager Steve Stich to reporters.

Problems with Boeing's Starliner capsule, still docked at the International Space Station (ISS), have upended the original plans for its return of its two astronauts to Earth, as last-minute fixes and tests draw out a mission crucial to the future of Boeing's space division.

NASA has rescheduled the planned return three times, and now has no date set for it. Since its June 5 liftoff, the capsule has had five helium leaks, five maneuvering thrusters go dead and a propellant valve fail to close completely, prompting the crew in space and mission managers in Houston to spend more time than expected pursuing fixes mid-mission.

Here is an explanation of potential paths forward for Starliner and its veteran NASA astronauts, Barry "Butch" Wilmore and Sunita "Suni" Williams.