The landing of the capsule, which has no passengers on board, should take place at 6:49 p.m. US east coast time (2249 GMT), in the desert of the US state of New Mexico, on the White Sands base. .

Its descent will be slowed down by its entry into the Earth's atmosphere, then by large parachutes, and contact with the ground will be cushioned by large airbags.

The stakes are immense both for Boeing, which has been trying to make this test flight a success for years, and for NASA, which has invested several billion dollars in the development of the spacecraft.

In the future, it wishes to hire its services to transport its astronauts to the International Space Station (ISS).

A landing carried out without incident would allow the aeronautical giant to finally conclude a successful mission from start to finish, after a failure in 2019. And at the same time to restore its image a little, after being overtaken by SpaceX, whose capsule has already served as a NASA taxi since 2020.

On Tuesday, Starliner's hatch was closed by astronauts aboard the ISS.

The capsule must detach from the station to begin its return trip at 2:36 p.m. Wednesday (6:36 p.m. GMT).

The Boeing space capsule, Starliner, a few meters from the International Space Station, during an unmanned test flight on May 20, 2022 - NASA TV/AFP

She brings with her 270 kg of cargo, including reusable oxygen tanks, which will be filled on Earth and returned to orbit later.

If the landing is postponed, for example due to unfavorable weather conditions, a new opportunity is possible on Friday.

Repeated pitfalls

Starliner took off from Florida last Thursday, and docked with the ISS for the first time the next day.

In recent days, many tests have been carried out to verify the proper functioning of the vehicle once connected to the flying laboratory.

But the success of the docking on Friday, in particular, had represented a real relief for Boeing, after a first attempt in 2019. Starliner had at the time had to turn back earlier than expected, before managing to reach the station.

The Boeing space capsule, Starliner, a few meters from the International Space Station, during an unmanned test flight on May 20, 2022 - NASA TV/AFP

The landing hadn't been a problem.

After this first failed mission and a long period of adjustments, the test flight was to be retried in August 2021. But when the rocket was already on the launch pad, the capsule's valves were blocked at due to a humidity problem.

The ship had had to return to the factory for repairs -- for ten months.

This time, the flight to the ISS went well, despite a problem detected in the propulsion system: two of the 12 thrusters used by the capsule to place itself on the correct trajectory after takeoff did not work.

The Boeing Starliner space capsule Laurence CHU AFP

These thrusters will be ignited again for the deorbit maneuver on Wednesday, intended to bring the capsule back into the Earth's atmosphere.

But NASA assured that this bug would not be a problem.

Next manned test

After this mission, a second demonstration flight, this time with astronauts on board, will have to be carried out for the spacecraft to obtain NASA certification.

Boeing hopes to achieve this by the end of the year and then start regular missions to the ISS.

But the exact timing will depend on the analysis of Starliner's performance in recent days.

Dress rehearsal before the landing of the Boeing space capsule, Starliner, in White Sands, New Mexico, on May 23, 2022 NASA/AFP

The US space agency has signed fixed-price contracts with both SpaceX and Boeing.

By using two companies, it wants to diversify its options, so as never again to risk finding itself without American means of transport, as after the shutdown of the space shuttles in 2011. Until SpaceX, NASA was indeed reduced to pay for seats on Russian Soyuz rockets.

Elon Musk's company, yet a newcomer to the aerospace industry compared to Boeing, has already transported 18 astronauts to the ISS with its own capsule, Dragon - as well as four private passengers, during a space tourism mission.

© 2022 AFP

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