The good news for Boeing’s Starliner capsule is that it finally brought humans to low-earth orbit. The issue is that it hasn’t gotten them down yet — and it may be a while before it does.

The issues that resulted in astronauts Butch Wilmore and Suni Williams extending their stay at the International Space Station were the culmination of years of shortcomings that have delayed the Starliner, NPR reported on July 3. The spacecraft is leaking some of the helium that is part of its propulsion system, the outlet reported, and a minority of its thrusters experienced issues.

In a telephonic press conference late last month, NASA official Steve Sitch said a thruster is being put through rigorous tests on the ground to try to replicate the issues observed in space. He said the tests could start July 2 and run for “a couple weeks.”

“I want to make it very clear that Butch and Suni are not stranded in space,” Sitch said. “They’re safe on the space station, their spacecraft is working well, and they’re enjoying their time on the space station.”

The delays underscore how Boeing has been getting lapped by SpaceX, which sent its eighth crewed NASA flight into orbit in March. The Elon Musk-led competitor has also gained ground in the national-security arena, the Wall Street Journal reported on July 1, ferrying more confidential cargoes like spy satellites to space than United Launch Alliance, Boeing’s joint venture with Lockheed Martin.

In addition to ground-based tests, NASA has been testing the Starliner’s thrusters and systems while it remains docked at the ISS. Wilmore and Williams aren’t alone; they joined Russian and American astronauts who were there on an existing mission, and space-agency officials said there is no shortage of supplies or anything that requires them to rush.

Still, the delays underscore Boeing’s business problems. The company’s commercial airliner business has been under regulatory scrutiny since a door plug blew out on an Alaska Airlines flight in January, and other outlets have reported that the US Justice Department is preparing criminal charges related to fatal crashes of its 737 MAX jets.

Ron Epstein, a Bank of America analyst, told NPR the company has focused on making money for its investors at the expense of its “core engineering business.”