Another disappointment for Boeing in the space race. The American company was forced on Tuesday to postpone an unmanned test flight of its Starliner capsule to the International Space Station (ISS) due to a technical problem in the propulsion system.

The Starliner capsule was to be shipped from Cape Canaveral, Florida to 12 h 13 this Tuesday by an unmanned Atlas V rocket operated by the United Launch alliance – a partnership between Boeing and Lockheed Martin. But about 2 hours before launch, Boeing announced the flight’s cancellation on Twitter.

New Window Wednesday Not because of the capricious weather, explained Nasa, but due to “unexpected indications on the position of the valves of the Starliner propulsion system”. The next possible firing window is Wednesday at 12 h 57. The launch had already taken a bit of delay as it was scheduled for last Friday but was postponed for a few days following a temporary loss of control of the ISS, a Russian science module having unexpectedly activated its thrusters after being docked at the ISS, changing its orientation.

For Boeing, this test flight is crucial because the first test in 2019 came close to disaster . On a first attempt, a software issue caused a problem with the way the capsule ignited its thrusters.

As a result, Starliner did not have enough fuel to reach the ‘ISS and turned back to Earth prematurely. An investigation then showed that the capsule had almost experienced a serious flight anomaly on entering the atmosphere.

In 2011, the NASA has ended its space shuttle program. The American agency then turned to Boeing and Elon Musk’s company SpaceX to do without Russian rockets to reach the ISS. The Crew Dragon capsule, developed by SpaceX, has already made it possible to send a dozen astronauts into space, including the French Thomas Pesquet .