Boeing's Starliner spacecraft is set to return to Earth today, marking the conclusion of a mission that has faced significant technical challenges. Launched on June 5 from Cape Canaveral Space Force Station in Florida, the mission, which carried astronauts Sunita Williams and Barry Wilmore, was originally intended to last just eight days. However, the return was indefinitely delayed due to issues with helium leaks and thruster malfunctions on the spacecraft.
Boeing's test flight was a critical demonstration of its commercial space capsule's ability to transport crews to the International Space Station (ISS). In a setback for Boeing, NASA announced on August 25 that Williams and Wilmore will instead return to Earth aboard SpaceX's Crew Dragon spacecraft in February 2025 as part of the SpaceX Crew-9 mission. Due to continued concerns with Starliner’s thrusters, the spacecraft will now make an uncrewed return.
NASA and Boeing engineers have acknowledged multiple risks associated with the capsule's re-entry. A too-steep re-entry angle could cause excessive friction, leading to the heat shield failing and potentially causing the spacecraft to burn up in the atmosphere in case some important thrusters fail.
Conversely, if the angle is too shallow, the Starliner could bounce off the Earth’s atmosphere and be flung back into space, leaving the capsule stranded in orbit and requiring an urgent retrieval mission. Furthermore, with one thruster already non-functional, there is a possibility of additional failures during the descent.
If more thrusters fail, the spacecraft could lose control, leaving the astronauts with only 96 hours of oxygen and power. In this scenario, NASA would face a race against time to resolve the issue or risk a potentially fatal outcome.
The Starliner capsule is scheduled to autonomously undock from the ISS today, with a planned landing at White Sands Space Harbor in New Mexico on Friday, September 6, at approximately 6:04 a.m. EDT (September 7, 3:30 a.m. IST), weather permitting. NASA will stream the departure and landing live on YouTube.
Despite these risks, NASA and Boeing remain confident in the spacecraft’s capabilities. During a press conference on September 4, they reassured that 27 of the 28 thrusters had been thoroughly tested and were operational. Additionally, the spacecraft will return valuable cargo, including reusable oxygen tanks, from the ISS.