Boeing's Starliner Capsule Scheduled for Earth Return Without Crew

Boeing is set to attempt the return of its troubled Starliner capsule from the International Space Station (ISS) later this week, with no crew on board. NASA confirmed on Wednesday that preparations are on track for the Starliner to undock from the ISS on Friday evening. The capsule is expected to land at New Mexico's White Sands Missile Range six hours after undocking.

Starliner’s Return and Crew Adjustments

NASA astronauts Butch Wilmore and Suni Williams, who flew up on Starliner, will stay at the ISS. They will return with SpaceX in February, eight months after their initial weeklong test flight was supposed to end. Thruster issues and helium leaks delayed their return, leading NASA to deem it too risky for them to accompany Starliner back.

The astronauts will close the hatches between Starliner and the ISS on Thursday. Now considered full-time station crew members, they assist with experiments and maintenance while increasing their exercise routines to counteract the effects of prolonged weightlessness.

SpaceX Adjustments for Upcoming Missions

To accommodate Wilmore and Williams on SpaceX's next mission, the Dragon capsule will launch with two astronauts instead of four. This adjustment was made late last week for the mission scheduled to launch in late September. Boeing must vacate the docking space for SpaceX's arrival.

Boeing faced significant issues with Starliner even before its June 5 liftoff for the delayed astronaut demo. The first test flight in 2019 failed due to software errors, preventing the capsule from reaching the ISS. This led to a repeat mission three years later, which also encountered problems, resulting in over $1 billion in repairs.

Technical Challenges and Solutions

The capsule experienced multiple thruster failures and helium leaks by the time it reached the ISS. Despite extensive thruster tests by Boeing, NASA decided it was unsafe for astronauts to return in Starliner, prompting a complex ride swap.

Starliner's return will be quicker and simpler than initially planned. Springs will push it away from the ISS, followed by short thruster firings to increase distance gradually. The original plan included an hour near the station for picture-taking, but this was reduced to 20 minutes to lessen stress on the thrusters and ensure station safety.

Additional test firings of Starliner's 28 thrusters are scheduled before its descent from orbit. Engineers aim to gather as much data as possible since the thrusters won't return to Earth; they will be discarded before reentry.

NASA’s Ongoing Collaboration with Boeing and SpaceX

The stuck astronauts, both retired Navy captains, have previously lived on the ISS and adapted well, according to NASA officials. Despite their mission changes, "they're just as dedicated for the success of human spaceflight going forward," said flight director Anthony Vareha.

Their blue Boeing spacesuits will return with Starliner, along with some old station equipment. NASA contracted Boeing and SpaceX a decade ago to transport astronauts after retiring its shuttles. SpaceX succeeded in 2020 and has since launched nine crews for NASA and four for private customers.

The journey has been challenging for Boeing's Starliner program. However, NASA's commercial crew program manager Steve Stich expressed optimism: "It's been a journey to get here and we're excited to have Starliner return."

As Boeing prepares for this critical mission, all eyes are on ensuring a safe return of the Starliner capsule while continuing collaborations with SpaceX for future missions.