Boeing, NASA prepare for uncrewed Starliner return on Friday

NASA officials expressed confidence that Starliner would return to Earth safely and successfully late Friday evening, but they’d enough concerns in regards to the spacecraft’s operation to say the journey ought to be made without humans on board.

The high-stakes mission is ready to officially end Friday, with Starliner attempting to separate at around 6:04 p.m. EST. If all goes in line with plan, the spacecraft will land at White Sands Space Harbor in New Mexico about six hours later.

These final maneuvers will bring to an end the troubled first crewed mission of Boeing’s Starliner. It was to be the last certification mission before the vehicle began operating as a daily technique of transport for astronauts traveling to and from the International Space Station. But technical problems, including issues with several of the spacecraft’s engines and several other helium leaks within the propulsion systems, emerged shortly before the vehicle attempted to dock with the station on June 6.

The two astronauts on board, Butch Wilmore and Suni Williams, eventually safely entered the ISS. However, the issues ultimately prolonged the mission by several months as NASA and Boeing engineers worked to find out the reason behind the anomaly. After weeks of testing, each on the bottom using replica equipment and in orbit, NASA ultimately decided on August 24 that Starliner should return to Earth empty, and Wilmore and Williams would return home using a SpaceX capsule in February 2025.

The return trip can have one major difference from normal ISS return missions: Starliner will conduct what’s called an “explosive burn” to quickly climb up and away from the station. This maneuver — which is definitely 12 small burns, each with an orbital speed of just 0.1 meters per second — will cause the engines to pulse for a shorter time frame than they did on the approach to the station. Because of this, the explosive burn likely won’t cause the identical problems engineers observed early within the mission, and subsequently won’t pose a security risk to the ISS, Steve Stich, NASA’s Commercial Crew Program manager, said during a news conference.

“The reason we decided to do this separation burn is that it gets the vehicle away from the station faster,” he said. “Without a crew on board to take over if necessary, there are just a lot fewer variables we have to consider when doing the separation burn, and it allows us to get the vehicle on a trajectory to get home faster.”

The next critical maneuver will likely be a 60-second deorbit burn that may place Starliner in Earth’s atmosphere and on its approach to White Sands. The spacecraft will deploy parachutes and airbags to make a soft landing on the bottom.

“We expect good burn and we have plenty of supplies, and we are relying on that to ensure a safe entry,” he added.

NASA and Boeing will conduct several months of post-flight evaluation of the spacecraft’s performance, but Stich said the teams are already considering system modifications or additional testing to get the vehicle fully certified by the space agency.

But it’s unclear what the ultimate path to certifying the spacecraft will likely be — let alone how rather more it may cost Boeing, which has already incurred greater than $1.5 billion in costs related to the Starliner program. It’s also unclear whether Boeing might want to fly one other crewed test mission.

If NASA and Boeing’s joint flight control team determine to not do the undocking on Friday, there will likely be several other opportunities in the approaching days. Astronauts aboard the space station have modified the SpaceX Dragon vehicle currently tethered to the station, equipping it with temporary seats in case of an emergency.