NASA announced it is delaying Boeing Starliner’s return to earth to further study “small helium system leaks and thruster performance.”

Starliner experienced issue on its flight to the International Space Station (ISS). The craft experienced two helium leaks, and some of its thruster unexpectedly went offline. In view of the issues, NASA and Boeing have decided to delay the craft’s return to Earth, originally scheduled for June 26, until the data can be reviewed.

“We are taking our time and following our standard mission management team process,” said Steve Stich, manager of NASA’s Commercial Crew Program. “We are letting the data drive our decision making relative to managing the small helium system leaks and thruster performance we observed during rendezvous and docking. Additionally, given the duration of the mission, it is appropriate for us to complete an agency-level review, similar to what was done ahead of the NASA’s SpaceX Demo-2 return after two months on orbit, to document the agency’s formal acceptance on proceeding as planned.”

The agency says that mission managers are looking return dates after two planned ISS spacewalks on June 24 and July 2. As a result, Starliner will not return until at least some time in July.

“Starliner is performing well in orbit while docked to the space station,” said Stich. “We are strategically using the extra time to clear a path for some critical station activities while completing readiness for Butch and Suni’s return on Starliner and gaining valuable insight into the system upgrades we will want to make for post-certification missions.”

“The crew’s feedback has been overwhelmingly positive, and they know that every bit of learning we do on the Crew Flight Test will improve and sharpen our experience for future crews,” said Mark Nappi, vice president and program manager, Boeing’s Starliner Program.

The delayed return is the latest in a raft of issues that have plagued Boeing’s Starliner. Starliner’s manned flight was scrubbed repeatedly due to issues, leading to questions about the program’s viability, especially in comparison to SpaceX.