Boeing's Starliner capsule, after its successful docking at the International Space Station (ISS), will have its return to Earth delayed for a few more days. The delay is a result of ongoing thruster troubleshooting and the scheduling of a spacewalk. NASA announced today that the conclusion of Starliner's first human mission, known as Crew Flight Test (CFT), will now take place no earlier than June 26, nearly three weeks after its launch.

Originally planned to spend about a week at the ISS, the departure of Starliner has been pushed back considerably due to the evaluation of thruster issues that disrupted its initial docking attempt on June 6. In addition, a postponed maintenance spacewalk at the ISS, which was initially scheduled on June 22, will now occur on June 24, just two days before Starliner's planned departure.

During a teleconference with reporters, Steve Stich, the manager of NASA's Commercial Crew Program, mentioned that the extra time will allow the teams to thoroughly analyze the data and ensure a safe return. Five of Starliner's 28 reaction control thrusters failed during its rendezvous with the ISS on June 6. Although four of them eventually came back online, further evaluation is still ongoing. A hot-fire test was conducted to gain more confidence in the thrusters' performance, which proved successful.

One thruster was excluded from the test due to abnormally low pressure observed during docking. As part of the investigation, a robotic camera on the space station's Canadarm2 was utilized to inspect the thrusters. The docking during the Crew Flight Test was more complex than a previous uncrewed test flight in May 2022, resulting in more frequent firing of the thrusters.

NASA's Marshall Space Flight Center is conducting hardware simulations to address ongoing helium leaks detected on Starliner. A small helium leak in one of the reaction control system (RCS) thrusters was discovered prior to the initial launch attempt in May. Additional leaks occurred during the mission, and an analysis is underway to determine the causes.

Further data review is needed to fully understand the thruster and helium leak issues. Certification of a new reentry mode was done after discovering a design vulnerability in the RCS system that could impact Starliner's return. Testing on the ground with the CFT crew, NASA astronauts Barry Wilmore and Suni Williams, helped validate the new reentry mode.

Despite these technical challenges, the mission has already achieved 77 out of 87 flight test objectives. The remaining objectives will be evaluated during the undocking and landing process. The delays also allowed for the rescheduling of a spacewalk that was initially postponed due to a spacesuit discomfort issue.

The return to Earth of the Starliner capsule will be broadcast live on NASA Television. The landing is scheduled to occur at White Sands Space Harbor in New Mexico at 4:51 a.m. EDT (0851 GMT) on June 26. Boeing and NASA remain committed to ensuring the safety and success of the Starliner program, as it plays a crucial role in NASA's strategy to send crewed missions to the ISS from American soil.

CFT is a pivotal developmental mission aimed at certifying Starliner for future operational missions. The capsule, along with SpaceX's Dragon, is contracted by NASA to transport its astronauts to the ISS. Together, they form a crucial part of NASA's plans to maintain its presence in space and foster international cooperation in space exploration.