NASA astronauts stuck on Boeing spacecraft face high stakes return from ‘incredibly important mission’: expert

The two NASA astronauts stuck on Boeing's Starliner spacecraft have an approximate return-by date of July 20. 

That's 45 days from its June 5 liftoff, which is how long Starliner can spend docked to the International Space Station (ISS). 

Astronauts Suni Williams and Butch Wilmore's original stay was scheduled for a week, but a series of issues, including recent helium leaks and thruster problems, pushed their homecoming back multiple times. 

"Operating in space, building these spacecraft...