The first crewed mission of Boeing’s new Starliner spacecraft faces more delays in its return from the International Space Station (ISS) as Boeing and NASA continue to evaluate the performance of its propulsion system, the space agency said on June 27.
The two NASA astronauts piloting the CST-100 Starliner—commander Barry “Butch” Wilmore and pilot Sunita “Suni” Williams—have been aboard the ISS for more than three weeks as NASA and Boeing have had to repeatedly push back the return date while addressing problems with the craft’s propulsion system. The initial return date of June 14 was first postponed until June 18 and then June 26, but neither Boeing nor NASA has provided a new date yet.
In a delay announced on June 21, NASA and Boeing said they were evaluating technical issues aboard the craft before approving its return to Earth.
“We are taking our time and following our standard mission management team process,” Steve Stich, head of NASA’s Commercial Crew Program, said at the time.
Mr. Stich said the craft is “performing well in orbit while docked” to the ISS, adding that more time to analyze Starliner would provide “valuable insight” into technical upgrades for its future missions.
The newest delay caused by the propulsion, however, is not a concern for the craft’s return, Boeing said, adding that the “astronauts are not stranded” aboard the space station.
Starliner launched from Cape Canaveral, Florida, on June 5, making it the first successful crewed mission aboard Boeing’s new spacecraft, which saw a decade of development and more than $5 billion in investment.
Reasons for Delays
NASA said it will continue to evaluate Starliner’s helium-based propulsion and thruster system, which is needed for maneuvering during flight. The craft successfully docked with the ISS on June 6 after experiencing leaks that disabled four of Starliner’s 28 thrusters. Ms. Williams and Mr. Wilmore were able to successfully restart three of the disabled thrusters before docking with the space station.Previous helium leaks were also responsible for delaying Starliner’s launch from the Kennedy Space Station, which was originally slated for early May before NASA pushed it back to June 5. Starliner launched with a small helium leak, but four more leaks were discovered before the craft reached the ISS a day later. NASA and Boeing previously said they believe the leak was the result of a faulty rubber seal in the helium tanks.
While the propulsion system is needed for steering Starliner in space ahead of its return, it detaches during reentry and burns up in the Earth’s atmosphere. NASA officials said they suspected that heat from the thrusters during docking resulted in their shutdown.
What’s Next?
Once the scheduled space walks are complete, NASA and Boeing plan to consider new return dates for Starliner. Mission managers will continue to probe the thruster and helium issues to resolve them ahead of Starliner’s next flight, which is scheduled for 2025 if Boeing wins NASA’s approval.NASA said Ms. Williams and Mr. Wilmore have been helping with chores and research aboard the ISS in between checking Starliner’s systems ahead of an eventual reentry. The agency said there is no rush for the two astronauts to leave the space station, as there are ample supplies for them and the seven others currently aboard.
If the flight is a success, Boeing will join SpaceX in sending astronauts to space in future missions. SpaceX has successfully sent crew members to the ISS aboard its Dragon capsule since 2020. The companies received $4.2 billion and $2.6 billion, respectively, to develop replacement spacecraft for NASA’s retired Space Shuttles.
Boeing was previously behind its schedule for Starliner after the first non-crewed flight in 2019 failed to reach the ISS. A subsequent flight in 2022 successfully reached the space station. Starliner also launched aboard a United Launch Alliance Atlas V rocket, which was used to send astronaut John Glenn into space in 1962, to become the first American to orbit the Earth.
