Is Sunita Williams Really 'Stuck' in Space or is it a Choice? NASA Starliner Astronauts Could Return as… | Mint

Are NASA astronauts Sunita Williams and Butch Wilmore really “stuck” in space, or is it their own choice to spend more time in weightlessness than planned? Below we explore two factors that may explain the idea behind Starliner astronauts' extended stays in space.

1. Starliner could return 'if absolutely necessary'

Steve Stich, manager of NASA's Commercial Crew Program, said earlier this month, “Starliner is 'go' for emergency return.” He made the statement as NASA insisted that Starliner could still return astronauts to Earth if necessary.

But under what circumstances would Sunita Williams and Butch Wilmore be brought back from space? The “absolutely necessary” situation would arise if the Starliner capsule needs to serve as an ISS rescue capsule in an emergency or if any of the Starliner's perishable items — such as its solar panels — show signs of deterioration earlier than planned, Reuters reported.

Wilmore said that on July 10, two astronauts tested a “Safe Haven procedure,” where they shelter in place in Starliner in case they suddenly had to undock from the ISS. The test went well, he said.

Meanwhile, Sunita Williams explained that one of the checks for Starliner was to practice a safe haven “to make sure we have all the emergency equipment ready and that we need to get into our spacecraft and use it as a safe haven – in case something happens to the space station,” she said.

An official also talked about how they would return to Earth if they did it today. On July 10, the official said that if they did the “undocking today,” they would just do a nominal undocking and come back. He said that the propulsion system is very redundant with each other. “So if there is a problem with one of the thrusters, the redundancy will take over and get us home safely,” he added.

2. Starliner isn't NASA's only option for bringing astronauts back

If not Boeing's Starliner, NASA also has the option of quickly recovering the two astronauts from space using a competitor's spacecraft, SpaceX's Dragon spacecraft, should there be a true emergency.

Crew Dragon carried four astronauts to the space station in March and can carry more people in an emergency. But using Crew Dragon seems unlikely. SpaceX is Boeing's competitor.

However, NASA is focused on Williams and Wilmore's safe return to Earth. The best option is to return with Boeing's Starliner capsule.

Why do Starliner astronauts stay in space so long?

Earlier this month, Wilmore said that human spaceflight is not easy in any regime and that there have been multiple problems with every spacecraft ever designed. “That's the nature of what we do.”

“The mantra “You have heard that failure is not an option, that is why we are staying here now,” he had said.

During their extended stay in space, Wilmore added, the crew experienced degradation in the thrusters. “And that's why we're staying, because we're going to test it… We're going to collect the data that we need to inform our decision, so we can make the right decision,” he said.

Meanwhile, Sunita Williams explained why studies of Starliner were important. She said that the service module (SM), where the thrusters are located, will detach from the capsule and burn up in the atmosphere. This would mean that it would no longer be possible to study how they react in space.

“We've been practicing a lot and I have a good feeling that the spaceship will bring us back home… we're learning now how to optimize our specific situation to make sure we know everything about it. [the spacecraft]…,” Sunita Williams said on July 10, during her first contact with the media after the Starliner launch.

NASA had previously rescheduled the planned return three times and has not set a date. According to a Reuters report, Starliner could remain docked with the ISS for up to 72 days, while relying on several backup systems.

Why has Starliner's return been delayed?

Starliner, scheduled to return in mid-June, has now been in space for more than 50 days as the crew continues to repair mid-mission issues. The team has been conducting booster tests and working on a readiness assessment for return flight in preparation for Starliner’s eventual separation and landing.

Starliner launched on Crew Flight Test (CFT) on June 5, carrying Butch Wilmore and Suni Williams to the International Space Station (ISS) for a planned week-long stay. The spacecraft reached the ISS on June 6.

During the journey, Starliner experienced helium leaks and thruster anomalies, which delayed the spacecraft's reentry. The capsule had five helium leaks, five maneuvering thrusters failed, and a propellant valve did not close completely.

Starliner's propulsion system is part of the craft's “service module.” The problems are concentrated in this system, which is needed to remove the capsule from the ISS and position it for a dive through Earth's atmosphere, Ruters reported.

According to Stich, many of the Starliner's thrusters overheated when fired, and leaks of helium — which is used to pressurize the thrusters — appear to be related to how often they are used.

On August 1, NASA said teams are taking the time to analyze the results of recent hot-air docking tests, finalize the flight logic for the spacecraft's integrated propulsion system and confirm the system's reliability before Starliner returns to Earth from the International Space Station.

What if the Starliner's thrusters fail on the return trip?

It is important that the thrusters perform nominally, and only then can Starliner undock and return safely. NASA and Starliner want to be absolutely sure before making the return trip and hope that “nothing else surprises us” during the journey.

So what if the thrusters are damaged? What would NASA do differently in that case? Mark Nappi, who leads the Starliner effort at Boeing, said they don’t believe they damaged the thrusters. But they want to “fill in the gaps and do some testing” to make sure everything is OK.

Adding to Nappi's answer, Steve Stich said that there was only one thrust engine producing very low thrust “that we would shut down for the remainder of the flight, and that's the plan for the… disconnect at this point, that would be the B1 A3 thrust engine. We wouldn't have that thrust engine available, and with the OMAC system for ignition, that should happen nominally…”

However, the two officials continued to maintain that they had complete confidence in the boosters.

The thrusters are needed to position the Starliner spacecraft for re-entry into the atmosphere and also to slow the capsule down to a good speed before the service module is released. After this phase, the capsule takes that final dive. To summarize: the mission has been delayed because at least one of the 28 thrusters failed.

NASA astronauts Sunita “Suni” Williams and Barry “Butch” Wilmore made history as the first people to fly aboard the Starliner spacecraft.