NASA is considering bringing the malfunctioning Starliner spacecraft back to Earth during an uncrewed flight, which may result in the astronauts aboard having to remain at the International Space Station (ISS) until 2025.
Stranded Starliner spacecraft from Boeing is currently delaying the Crew-9 mission to the ISS, with NASA contemplating whether to cut the crewed return flight of this spacecraft as details regarding the issues aboard the Starliner become clearer. The delay has pushed the launch schedule for the Crew-9 mission from September 18 to September 24, allowing the mission management team more time to finalize the return plan for Boeing’s Crewed Flight Test, according to Live Science.
Starliner spacecraft as seen from the ISS. (Photo: NASA).
The Crew-9 members are scheduled to replace the current Crew-8 astronauts on the ISS, but they cannot arrive until there is a docking port available. The priority module is Harmony, which has been docked with the stranded Starliner at the ISS since June. Authorities have yet to determine the return date for the Boeing spacecraft or the astronauts aboard, who have now spent several months longer at the ISS than originally planned. NASA engineers are debating whether to allow the Starliner to return uncrewed to Earth and transport the astronauts back using a SpaceX vehicle in early 2025.
“The likelihood of the uncrewed Starliner returning to Earth has increased slightly based on developments over the last week or two. That’s why we are looking more closely at that option,” said Ken Bowersox, NASA’s Deputy Associate Administrator for Human Spaceflight.
The issues began shortly after NASA astronauts Butch Wilmore and Sunita Williams successfully launched into orbit on Boeing’s spacecraft after years of delays, marking the first crewed flight of the Starliner from Cape Canaveral Space Force Station in Florida on June 5. Originally, Wilmore and Williams were to stay in orbit for one week, but during the flight, the Starliner encountered a series of problems, including five helium leaks and five issues with the propulsion system’s reaction control engines. This forced engineers to troubleshoot from the ground, extending the two astronauts’ stay at the ISS from one week to two months.
Nasa’s engineering team indicated that they need more time to collect data on the reliability of the Starliner and to address the ongoing issues. However, progress towards the return flight has stalled. NASA hopes to start evaluating the spacecraft’s readiness for flight in early August, but that process has not yet begun. Tests conducted by engineers at Starliner in White Sands, New Mexico, revealed that when the spacecraft was flying to the ISS, Teflon valve failures in five RCS thrusters likely overheated and blew out, obstructing the fuel flow, according to NASA.
Tests activating the engines conducted when the Starliner docked with the ISS on July 27 showed normal thrust, but NASA engineers are concerned that the issues may reoccur during the spacecraft’s return to Earth. They are also worried that helium leaks could affect some of the thrusters in the orientation control and operations in orbit (OMAC), which help the spacecraft maintain its trajectory.
One reason for the flight delay is that the Starliner cannot autonomously undock from the ISS, a necessary operation if NASA decides the spacecraft will return without carrying astronauts. Updating and testing the software required for this operation will take four weeks. NASA is also preparing several contingency plans, including sending two Crew-9 astronauts to the ISS instead of four, so that Wilmore and Williams can return with them in February 2025.
