NASA’s Sunita Williams, Barry Wilmore face 96-hour oxygen limit on Starliner: Expert warns of space standoff

Sunita Williams and Barry Wilmore – astronauts of the National Aeronautics and Space Administration (NASA) – have been stuck in space for more than two months now. Wilmore and Williams blasted off for the International Space Station (ISS) on Boeing's Starliner on June 5.

They were meant to stay on the ISS for eight days. However, their return has been delayed by thruster malfunctions that came to light during the first crewed mission to the ISS by a Boeing spacecraft.

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There are widespread concerns about when will the two astronauts return and how safe will their entry back home be.

Addressing a press conference last week, NASA officials said that they were still analysing thruster data, but a decision on whether to use Starliner or SpaceX was looming.

Rudy Ridolfi, former Space System Commander in the US military, explained three frightening scenarios that could play out if they choose to go ahead with Starliner for the astronauts' journey back to Earth.

The scenarios by Ridolfi

Speaking to The Daily Mail earlier this month Ridolfi said that if Williams and Wilmore were to return back home in the Starliner, they could vapourise uponre-entry of Earth's orbit or be stuck floating in space.

Five thrusters failed during the 24-hour journey that took the two astronauts to the ISS back in June.

One of the mainconcerns is that more thrusters could fail on the return leg,leaving them floating in limbo, somewhere between the ISS and Earth.

The Daily Mail report on August 8 said that based on the amount of oxygen and power capabilities that Starliner has, the crew would have about 96 hours to revive thrusters and land back on Earth.

The crew would need to determine which thrusters have malfunctioned with the hopes of sealing them and still have enoughresources to spend a few hours travelling home.

It could be possible that the craft does make it to Earth even in this scenario, Ridolfi told the publication.

A rescue craft to Starliner ship

The report also pointed out that in a worst-case scenario,NASA could be forced to send a rescue craft to the Starliner ship to retrieve Williams and Wilmore.

Such a rescue has only been performed once and that too to rescue an unmanned spacecraft.

"NASA knows how to do this, but it just takes time.If Starliner bounces off the atmosphere they have to locate it. You can get a general guess of where it is, but you have to start taking radar, and optical observations and calculate the orbit that it's now in."

This rescue mission can be accomplishedby attaching a tunnel-like structure that would latch onto Starliner's hatch, allowing it to open without harming the astronauts.

In this situation, Ridolfi said that once Starliner is located, NASA would have to train another team of astronauts to perform the docking mission.

(With inputs from agencies)