NASA and Boeing are evaluating the Starliner engine and have completed ground tests, including a reaction control engine test at White Sands that revealed a performance degradation. More hot fire tests are planned at the dock to check the engine’s thrust and helium leaks. An agency-wide review will be conducted to finalize the return plan, and a televised briefing is expected.

NASA and Boeing management provided an update on the Starliner crew’s flight tests at a press conference on July 25. The combined Starliner team continues to evaluate the performance of the spacecraft’s propulsion system and perform other tasks before it is scheduled to depart the International Space Station and return to Earth.

Watch the full replay of the press conference:

NASA and Boeing engineering teams recently completed testing of the Starliner reaction control engine at White Sands Proving Ground in New Mexico. The series of tests involved running the engine under conditions similar to those encountered by the spacecraft during its approach to the space station. The tests also included various stress scenarios to simulate the conditions expected during Starliner’s docking and deorbit, which would bring the spacecraft down for a landing in the southwestern United States. The teams are currently disassembling the engine for physical testing. Initial results show engine performance degradation consistent with what was observed in orbit.

Preparing to return to Earth

Additionally, NASA and Boeing conducted a second hot fire test at the docking station over the weekend to demonstrate the spacecraft’s engine performance. The first hot fire test at the docking station took place on June 15. The new test will check for helium leaks as well as verify that the engines are functioning properly.

NASA plans to conduct an agency-wide readiness review as soon as this week. Following verification, mission management will develop a plan for a normal return to Earth and select a target date for Starliner docking. NASA also plans to hold a televised briefing with agency and Boeing management following the review. More press conference details will be provided as they become available.

Starliner launched on June 5 and docked with the ISS on June 6. It was originally scheduled to return to Earth on June 14. NASA astronauts Butch Wilmore and Suni Williams continue to provide additional crew time and valuable contributions aboard the space station, assisting with research science and helping ground crews collect critical data for Starliner’s long-duration flights to the orbital complex after certification.