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Starliner undocks from ISS for six-hour return trip to

Earth

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Boeing's ( BA ) Starliner faces technical issues, costing $125

million

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Boeing's ( BA ) future in space questioned amid Starliner

struggles

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Astronauts' 8-day test turns into 8-month mission

By Joey Roulette

WASHINGTON, Sept 6 (Reuters) - Boeing's ( BA ) Starliner

spacecraft undocked from the International Space Station on

Friday, leaving behind its first crew of U.S. astronauts to

return to Earth empty and finish a drawn-out test mission

fraught with technical issues.

NASA astronauts Butch Wilmore and Suni Williams, who became

the first two to fly Starliner in June, remained on the ISS with

seven other astronauts 250 miles (400 km) in orbit as Starliner

autonomously departed the laboratory at 6:04 p.m. ET (2204 GMT)

for a six-hour journey toward Earth.

The two astronauts bid farewell to a capsule whose

propulsion system problems stretched their eight-day test into

an eight-month mission. Stocked with extra food and supplies,

Wilmore and Williams will instead return on a SpaceX vehicle in

February 2025, NASA announced last week.

Since then, Boeing ( BA ) engineers have uploaded new software to

Starliner that allows it to come back without a crew inside. The

return trip will be a key test of Starliner's maneuvering

capability.

The capsule is poised to use its maneuvering thrusters to

gradually lower its orbit and reenter Earth's atmosphere at

around 11:17 p.m. (0317 GMT on Saturday), followed by a 12:03

a.m. parachute-assisted touchdown at the White Sands Space

Harbor, an arid military test site in New Mexico.

Five of Starliner's 28 maneuvering thrusters had failed with

Wilmore and Williams on board during their approach to the ISS

in June, while the same propulsion system sprang several leaks

of helium, which is used to pressurize the thrusters.

Despite successfully docking on June 6, the failures set off

a monthslong investigation by Boeing ( BA ) - with some help from NASA

- that has cost the company $125 million, bringing total cost

overruns on the Starliner program just above $1.6 billion since

2016, according to a Reuters analysis of securities filings.

Boeing's ( BA ) Starliner woes have persisted since the spacecraft

failed a 2019 test trip to the ISS without a crew. Starliner did

a re-do mission in 2022 and largely succeeded, though some of

its thrusters malfunctioned.

The aerospace giant's Starliner woes represent the latest

struggle that call into question Boeing's ( BA ) future in space, a

domain it had dominated for decades until Elon Musk's SpaceX

began offering cheaper launches for satellites and astronauts

and reshaped the way NASA works with private companies.

Boeing ( BA ) hopes to recover the Starliner capsule after it

touches down in New Mexico and continue its investigation into

why the thrusters failed in space.

But the section housing Starliner's thrusters - the "service

module" trunk that provides in-space maneuvering capabilities -

is designed to detach from the capsule just before it plunges

into Earth's atmosphere.

The service module bearing the faulty thrusters will burn up

in the atmosphere, meaning Boeing ( BA ) will rely on simulated tests

to figure out what went wrong with the hardware in space.

Starliner, bearing a heatshield to survive its own reentry,

will deploy a series of parachutes to slow its descent and

inflate a set of exterior airbags moments before touchdown to

cushion the impact.