Astronauts from Boeing’s Starliner were supposed to be in space for 8 days. Now they’re stuck there with no scheduled return date.

But 12 days after the crew arrived at the ISS, Boeing announced that their return to White Sands Space Harbor in New Mexico had been delayed to June 26.

On Friday, the aviation company said the return was delayed again to assess issues on board and to make time for two spacewalks. The delay comes after five helium leaks were detected on board the spacecraft. Helium supports the spacecraft’s reaction control system (RCS) thrusters, allowing them to fire.

“Mission managers are evaluating future return opportunities following the station’s two planned spacewalks on Monday, June 24, and Tuesday, July 2,” Boeing said in its statement.

Boeing also has not provided a new scheduled date for the astronauts’ return.

“We are taking our time and following our standard mission management team process,” Steve Stich, manager of NASA’s Commercial Crew Program, said in the statement.

However, the statement said that the crew was not “not pressed for time to leave the station,” as there were “plenty of supplies in orbit.”

The voyage to the ISS isn’t Wilmore’s and Williams‘ first time in space.

Suni Williams, who was selected to be an astronaut by NASA in 1998, had spent a total of 322 days in space before the Starliner project. And Butch Wilmore, who has been a NASA astronaut since 2000, logged 178 days in space before the Starliner launch.

This is the first instance of Boeing sending up a crewed spacecraft in an attempt to break into the commercial human-space transport business. But the company now lags behind Elon Musk’s SpaceX, which has been sending astronauts to space since 2020.

Boeing and SpaceX were the two American companies selected by NASA in 2014 to explore commercial space transport.

Preceding the Starliner’s launch, Musk pointedly said on X in May that Boeing was weighed down by “too many non-technical managers.”

Back on earth, Boeing has also been plagued by plane issues in recent months. In January, a door plug came off a Boeing 737 Max 9 Alaska Airlines jet at 16,000 feet, resulting in a gaping hole in the plane.

Several Boeing whistleblowers have since come forward with bombshell testimonies alleging that the company cut corners with quality control.

Boeing and NASA didn’t immediately respond to a request for comment from Business Insider, made outside normal working hours.