NASA is wrestling with how and when to bring two astronauts back from the International Space Station after their return aboard a troubled Boeing space capsule was repeatedly delayed.
Barry “Butch” Wilmore and Sunita “Suni” Williams have been up there since June 5, recently passing the two-month mark of their original eight-day mission.
The pair launched into orbit on the first manned mission of Boeing’s Starliner space capsule, but encountered technical difficulties during the ascent.
The capsule is currently still being tested. Boeing is confident about its spacecraft, but NASA experts are divided.
Will they take the risk and send them home soon in the Starliner? Or will they wait and bring them back in February 2025 aboard Elon Musk’s SpaceX Dragon rocket?
A decision is expected in the course of the coming week.
What’s wrong with the spaceship?
For Boeing, it is the first flight with astronauts after two previous empty Starliners that suffered from software problems and other difficulties.
Even before Mr Wilmore and Ms Williams took off in June, there was a leak in the propulsion line of their capsule.
Boeing and NASA assumed the small helium leak was stable and isolated and conducted the test flight. But as the Starliner approached the space station the next day, four more leaks appeared. In addition, five engines failed.
The capsule docked safely and four of the engines eventually worked, but engineers desperately tried to identify the problem and conducted test runs of the engines on the ground and in space.
After two months, the cause of the engine failure is still unknown. All 28 engines appear to be working except one, but there are fears that crew safety could be at risk if too many fail again.
Thrusters are critical to maintaining the correct position of the capsule during deorbit.
Are the two astronauts stranded?
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NASA reacts with outrage to any suggestion that the pair is stranded or pinned down.
The agency has stressed from the outset that in the event of an emergency on the space station, such as a fire or decompression, the Starliner could still be used as a lifeboat for exit.
Former NASA executive Scott Hubbard said Thursday the astronauts were “kind of stuck” but certainly not stranded. He added that they had plenty of supplies but there was still a lot of work to be done.
If NASA decides to return with SpaceX, the two would not simply board the Dragon, which is currently docked at the ISS – a move that would leave other astronauts without a lifeboat.
Instead, the Starliner would be cut loose to free up one of the two docking slots reserved for U.S. capsules, and SpaceX would then launch another Dragon rocket to fill that slot.
Why might they have to wait until 2025?
Like Boeing’s Starliner, SpaceX’s Dragon will carry four astronauts.
To make room for Mr Wilmore and Ms Williams, NASA said it may withdraw two of the four astronauts scheduled to launch to the space station with SpaceX next month.
The empty seats would be reserved for the pair, but they would have to wait until February to return, when the remaining crew completes their mandatory minimum station mission of six months.
Some missions lasted a year.
There are no plans to order a special SpaceX Express, and the Dragon at the station will now begin the journey home for four residents next month.
This is not the first time that a US astronaut’s stay has been extended.
NASA astronaut Frank Rubio and his two Russian crewmates spent just over a year in space after their docked Soyuz capsule was hit by space debris and leaked all of its coolant. Last September, an empty Russian capsule was sent into space to retrieve them.
What do the astronauts think about this?
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Both Wilmore, 61, and Williams, 58, are retired Navy captains and longtime NASA astronauts who have participated in space station missions.
They had previously stated that they expected this test flight to provide them with a lot of information about the Starliner and how it works.
During a press conference from space in July, they assured reporters that they were busy helping with repairs and research, and expressed confidence in the Starliner tests taking place behind the scenes.
They have not yet commented publicly on the prospects of an eight-month stay.
Is there enough stock?
The astronauts’ suitcases were removed from the Starliner before launch to make room for equipment urgently needed for the space station’s urine-to-drinking water recycling system.
Since then, they have had to make do with the spare clothes they already have up there.
This week, a supply ship finally arrived with their clothing, as well as additional food and scientific experiments for the entire nine-person crew.
Further deliveries are expected in a few months.
As for air, the space station has its own oxygen production systems.
But despite the reserves, NASA wants to return to normality as quickly as possible.
Besides Mr Wilmore and Mrs Williams, there are four other Americans and three Russians on board.
Why is NASA sticking with the Starliner?
NASA deliberately commissioned two companies to transport its crews to and from the space station, just as it did for cargo delivery.
The space agency viewed it as a kind of insurance policy: if one crew or cargo carrier had to remain on the ground, the other could carry the load.
“You want to have another alternative, both for cost reasons and for safety reasons and options,” said Scott Hubbard, who served on the Columbia accident investigation board in 2003.
“To be successful, NASA needs Boeing.”
Despite recent setbacks, NASA insists on continuing to use Boeing Starliner for astronaut flights.
The goal is to launch a crewed Dragon and Starliner space shuttle every six months until the space station is decommissioned in 2030. SpaceX has been involved since 2020.
What does Boeing say?
The aerospace company insists that its capsule can still bring the astronauts home safely, but says it will take the necessary steps to return the capsule empty should NASA decide to do so.
Last week, Boeing released a list of all the tests that have been conducted on the engines since launch.
“We continue to believe in the performance and flight capability of the Starliner,” it said.
Boeing, a long-time aerospace supplier, has struggled with numerous problems with the Starliner over the years.
The company had to launch an empty spacecraft twice before it could hire a crew. The first flight test had to be repeated because of faulty software and other problems. The delays have cost the company about $US1.6 billion ($2.4 billion) since 2016.
Mr. Hubbard questioned whether NASA and Boeing should have launched the crew despite the original helium leak, which caused further problems.
“Whatever happens to the Starliner, they need to figure out what the problem was and fix it,” he said.
“And give everyone the reassurance that they are still involved in the aerospace industry on a large scale.”
AP
