STORY: SUNITA WILLIAMS: "I have a real good feeling in my heart that the spacecraft will bring us home, no problem."

The first two astronauts to fly Boeing's Starliner capsule say they're "confident" it can bring them home.

They've already been in space much longer than expected.

Barry "Butch" Wilmore and Sunita "Suni" Williams had their first news conference since docking to the International Space Station more than a month ago.

BARRY WILMORE: "Absolutely confident."

WILLIAMS: "I feel confident that if we had to, if there was a problem with the International Space Station, we can get in our spacecraft and we can undock, talk to our team and figure out the best way to come home."

The veteran NASA astronauts and former U.S. Navy test pilots are waiting for the company and the U.S. space agency to fix an array of thruster issues.

They were launched aboard Starliner on June 5 from Florida and docked the next day at the ISS.

They were supposed to spend about eight days there.

Now, their mission has been extended indefinitely due to a series of issues with Starliner's propulsion system.

WILMORE: You know, that mantra you've heard, failure is not an option. That's why we are staying here now."

WILLIAMS: "It feels good to float around. It feels good to be in space and work up here with the International Space Station team. So, yeah, it's great to be up here. So I'm not complaining, Butch isn't complaining that we're here for a couple of weeks, extra weeks."

Five of Starliner's 28 maneuvering thrusters went dead during its 24-hour trek to the station, a propellant valve failed to properly close and there have been five leaks of helium, which is used to pressurize the thrusters.

The current test mission is Boeing's final step before the spacecraft can clinch NASA certification for routine astronaut flights.

That would make it the second U.S. orbital capsule alongside SpaceX's Crew Dragon.

A NASA chief has said extra testing could last at least a "couple weeks" before Starliner gets the green light to bring the astronauts back to Earth.

NASA and Boeing have said it is capable of getting them home in the event of an emergency on the ISS.

But the capsule is not approved to fly home under normal, non-emergency circumstances until its thruster issues are resolved--or at least better understood.

NASA and Boeing officials have emphasized that the two astronauts are not stranded in space.