Boeing’s Starliner deemed too risky for crew returns to Earth leaving astronauts behind

WASHINGTON – Boeing’s Starliner spacecraft landed uncrewed in a New Mexico desert late on Sept 6, capping a three-month test mission hobbled by technical issues that forced the astronauts it had flown to the International Space Station (ISS) to remain there until 2025.

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 10.04am GMT (6.04am Singapore time) on Sept 6, beginning a six-hour trek to Earth using manoeuvring thrusters that Nasa in August deemed too risky to be used with a crew on board.

Starliner returned to Earth seemingly without a hitch, a Nasa live stream showed, nailing the critical final phase of its mission.

The spacecraft re-entered Earth’s atmosphere at orbital speeds of roughly 27,400kmh. 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 Harbour, a 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 in August to keep astronauts off the capsule over safety concerns threw the spacecraft’s certification path into uncertainty, despite the clean return Boeing executed.

Mr Wilmore and Ms Williams, stocked with extra food and supplies on the ISS, will return to Earth via a SpaceX spacecraft 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 400km in space, has seven other astronauts on board who arrived at different times on other spacecraft, including a Russian Soyuz capsule. Ms Wilmore and Ms Williams are expected to continue doing science experiments with their crewmates.

Five of Starliner’s 28 manoeuvring thrusters had failed with Mr Wilmore and Ms 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 pressurise the thrusters.

Despite successfully docking on June 6, the failures set off a months-long investigation by Boeing – with some help from Nasa – that has cost the company US$125 million (S$163 million), bringing total cost overruns on the Starliner programme just above US$1.6 billion since 2016, according to a Reuters analysis of securities filings.

Boeing’s Starliner woes have persisted since the spacecraft failed a 2019 test trip to the ISS without a crew. Starliner did a redo mission in 2022 and largely succeeded, though some of its thrusters malfunctioned.

The aerospace giant’s Starliner woes represent the latest struggle that calls into question Boeing’s future in space, a domain it had dominated for decades until Mr Elon Musk’s SpaceX began offering cheaper launches for satellites and astronauts, and reshaped the way Nasa works with private companies.

Boeing 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 manoeuvring capabilities – is designed to detach from the capsule just before it plunges into Earth’s atmosphere.

The service module bearing the faulty thrusters burns up in the atmosphere, meaning Boeing will rely on simulated tests to figure out what went wrong with the hardware in space.

Starliner, bearing a heat shield to survive its own re-entry, deploys a series of parachutes to slow its descent and inflates a set of exterior airbags moments before touchdown to cushion the impact. REUTERS