NASA: No return date yet for astronauts aboard ISS

Two NASA astronauts who were supposed to return from the International Space Station over a month ago are still orbiting Earth as engineers finish working on problems plaguing their Boeing Starliner 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 capsule prompted NASA and Boeing to keep them up longer.

No return date yet

FILE - Side-by-side images showing the Boeing Starline spacecraft docked at the International Space Station and an image of a United Launch Alliance Atlas V rocket with Boeing's CST-100 Starliner spacecraft aboard. (Credit: Getty Images/Joel Kowsky/N

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

"We’ll come home when we’re ready," said Stich, adding that the goal is to bring Wilmore and Williams back aboard Starliner. 

Stich acknowledged that backup options are under review. 

Starliner launched on June 5, the third attempt in just under a month to get the spacecraft safely into the atmosphere. It experienced one helium leak before blasting off and two more leaks before docking with the ISS, NASA previously said. 

The Associated Press contributed to this report. This story was reported from Los Angeles.