Nasa astronaut Sunita "Suni" Williams and her colleague Butch Wilmore will not return to Earth in July as their departure has been delayed again.
The delay follows extensive ground testing and inspections of the Reaction Control System (RCS) thruster on the Starliner spacecraft. The Starliner team is now reviewing the data to ensure a safe return for the astronauts.
The RCS thruster testing at Nasa’s White Sands Test Facility in New Mexico provided critical insights for root cause assessments and helped finalise the flight rationale for a nominal undock and landing.
“I’m very confident we have a good vehicle to bring the crew back with,” said Mark Nappi, Starliner program manager and vice president, during a news conference.
The team plans to hot fire 27 of the 28 RCS thrusters this weekend while the spacecraft remains safely docked at the International Space Station (ISS). This test aims to verify the thrusters’ performance and gather additional helium leak data, which has remained stable since the spacecraft’s arrival on June 6.
“Our mission was to get the crew to the ISS, and that has been completed. Our mission was to learn from a flight test. Now it’s time to focus on returning the crew safely,” Nappi added.
As preparations continue, the team has also been conducting standard spacecraft maintenance and system checkouts. Wilmore, Williams, and flight control teams powered up the spacecraft to load updated undock and landing software and download VESTA imagery.
They also measured two floor panels within the Starliner Crew Module to support future powered-payload installations.
The crew has been actively participating in undock-to-landing simulations on-orbit, working with Boeing’s Avionics and Software Integration Lab (ASIL) in Houston. These simulations are crucial for maintaining proficiency during future long-duration missions.
Last week, Wilmore successfully tested Starliner’s unique backup control capability using a tablet-based simulator and physical joystick.
Nasa Commercial Crew Program Manager Steve Stich reported that the crew is in good spirits and enjoying their time on the ISS as part of the Expedition 71 crew. Both Williams and Wilmore have previous experience with long-duration missions, which has helped them adapt to the extended stay.
In addition to mission-specific tasks, Wilmore has been involved in various station activities, including moving hardware, reconfiguring power systems, collecting air samples, and monitoring Earth’s weather from the Cupola. He also underwent ultrasound scans to study how the human body adjusts to exercising in space.
The landing date for the Starliner Crew Flight Test (CFT) will be scheduled following the Flight Test Readiness Review planned for next week, with landing opportunities available throughout August.
