The Boeing spacecraft: What went wrong?

The astronauts launched aboard the Starliner on June 5. The following day, they faced difficulties.

As Starliner neared the International Space Station, five of its 28 Reaction Control System thrusters failed, causing a nearly one-hour delay in the docking process.

Located on the spacecraft’s service module, these thrusters are crucial for maneuvering the capsule in orbit, especially during docking and undocking with the space station.

Although all four thrusters were eventually fixed, prompting NASA to launch an investigation into the cause of the failure.

Engineers from NASA and Boeing have been testing the thruster performance using a test engine at the White Sands Test Facility in New Mexico, under conditions similar to those experienced by the capsule during its journey to the space station.

Mission managers also performed a “hot fire test” by firing Starliner’s thrusters briefly while docked to the space station.

Initial results revealed that most of the thrusters operated normally, but a small Teflon seal expanding at high temperatures potentially blocked propellant flow to the thruster, leading to the docking issues.

Steve Stich, NASA’s commercial crew program manager, mentioned the need for further testing to ensure ground tests accurately simulate on-orbit conditions. They also want to understand how the thruster issues impact Starliner’s ability to undock safely from the space station.

Additionally, the team is monitoring the spacecraft’s propulsion system for slow helium leaks.

Despite knowing about a helium leak before Starliner’s launch, officials discovered two more leaks in the capsule’s service module shortly after liftoff.

NASA confirmed that the propulsion system was stable and that the rate of helium leaks was not critical for the spacecraft’s return to Earth.

Further testing and analysis were conducted by additional propulsion experts hired by the company earlier this month.

The decision to return Wilmore and Williams aboard Starliner or use SpaceX for their return will determine their orbital stay extension into the new year, potentially until February for Wilmore, who could return with two other crew members aboard SpaceX’s Crew Dragon spacecraft.

NASA is expected to announce its decision on the astronauts’ return in the coming days.