*

Starliner lands in New Mexico desert after troubled

mission

*

NASA astronauts Wilmore and Williams to return on SpaceX

vehicle

in February 2025

*

Boeing's ( BA ) Starliner program faces $1.6 billion in cost

overruns

since 2016

(Updates after Starliner returns to earth)

By Joey Roulette

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

spacecraft landed uncrewed in a New Mexico desert late on

Friday, capping a three-month test mission hobbled by technical

issues that forced the astronauts it had flown to the

International Space Station to remain there until next year.

NASA astronauts Butch Wilmore and Suni Williams, who became

the first crew to fly Starliner in June, remained on the ISS as

Starliner autonomously undocked at 6:04 p.m. ET (2204 GMT) on

Friday, beginning a six-hour trek to Earth using maneuvering

thrusters that NASA last month deemed too risky for a crew.

Starliner returned to Earth seemingly without a hitch, a

NASA live stream showed, nailing the critical final phase of its

mission.

The spacecraft reentered Earth's atmosphere at around 11

p.m. ET at orbital speeds of roughly 17,000 miles (27,400 km)

per hour. About 45 minutes later, it deployed a series of

parachutes to slow its descent and inflated a set of airbags

moments before touching down at the White Sands Space Harbor, an

arid desert in New Mexico.

Though the mission was intended to be a final test flight

before NASA certifies Starliner for routine missions, the

agency's decision last month to keep astronauts off the capsule

over safety concerns threw the spacecraft's certification path

into uncertainty, despite the clean return Boeing ( BA ) executed.

Wilmore and Williams, stocked with extra food and supplies

on the ISS, will return to Earth on a SpaceX vehicle in February

2025. What was initially supposed to be an eight-day test has

turned into an eight-month mission for the crew.

The ISS, a football field-sized science lab some 250 miles

(402 km) in space, has seven other astronauts on board who

arrived at different times on other spacecraft, including a

Russian Soyuz capsule. Wilmore and Williams are expected to

continue doing science experiments with their crewmates.

Five of Starliner's 28 maneuvering thrusters 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 cFompanies.

Boeing ( BA ) will recover the Starliner capsule after its

touchdown and continue its investigation into why the thrusters

failed in space.

But the section that housed Starliner's thrusters - the

"service module" trunk that provides in-space maneuvering

capabilities - detached from the capsule as designed just before

it plunged into Earth's atmosphere.

The service module bearing the faulty thrusters burned up in

the atmosphere as planned, meaning Boeing ( BA ) will rely on simulated

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