The Boeing CST-100 Starliner crew has received promising news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have left it in orbit since early June, has now been completed on the ground. Boeing and NASA had awaited these tests to start planning the spacecraft’s return journey.
An update provided last week indicated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The purpose of this testing was to analyze thruster degradation and understand why certain thrusters malfunctioned during flight. Officials emphasized that some thrusters had to be “de-selected” due to performance issues.
Prior to and during the Starliner launch, helium tanks that control the thrusters experienced leaks, causing multiple delays. Although the spacecraft has 70 hours’ worth of helium aboard—significantly more than the seven hours it requires—officials stated that while the Starliner could technically return to Earth now if necessary, they are not fully prepared for its departure.
NASA and Boeing had previously suggested that a return flight might occur by the end of this month. However, the timeline has become less specific, with recent statements indicating that, “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue finalizing flight rationale for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”