No return date yet for astronauts and Boeing capsule at space station: Nasa

Already more than a month late getting back, two NASA astronauts will remain at the International Space Station until engineers finish working on problems plaguing their Boeing capsule, officials said Thursday.

Test pilots Butch Wilmore and Suni Williams were supposed to visit the orbiting lab for about a week and return in mid-June, but thruster failures and helium leaks on Boeing's new Starliner capsule prompted NASA and Boeing to keep them up longer.

NASA's commercial crew program manager Steve Stich said mission managers were not ready to announce a return date.

Engineers last week completed testing on a spare thruster in the New Mexico desert to try to understand what went wrong during docking and to prepare for the trip home. Five thrusters failed as the capsule approached the space station on June 6, a day after liftoff. Four have since been reactivated.

After the space shuttles retired, NASA hired private companies for astronaut rides to the space station, paying Boeing and