USA "Starliner" makes it back - space odyssey continues

The space odyssey of astronaut Suni Williams and astronaut Barry Wilmore could have been over already. Their spaceship "Starliner" landed safely on Earth - but the two are still on the International Space Station ISS. A return flight with the broken-down spacecraft was deemed too unsafe by the US space agency NASA. Now they are to spend eight months in space instead of eight days as originally planned.

When the capsule undocked from the ISS in a controlled manner and touched down gently in the desert of the US state of New Mexico, there was a huge sigh of relief at Nasa. "It's great that the Starliner is back," said Nasa manager Steve Stitch at a press conference. And many people wondered: couldn't the astronauts have been sent along in the capsule?

An engine also failed on the return flight

However, there were also minor inconsistencies on the return flight of the capsule, which was manufactured by the US company Boeing and took around six hours. Two of the 28 engines showed a slightly too high temperature, and one did not fire as planned on re-entry into the earth's atmosphere, explained Stitch. Communication had been tried in two different ways, but the engine had not responded. As the system was redundant, it was possible to control it in another way.

On the outward flight, five engines overheated and failed, and helium also escaped through leaks. The capsule finally docked with the space station. The return flight, originally planned for June, was postponed by three months. During this time, experts tried to get to the bottom of the problems. The engines were test-fired twice during the time on the ISS.

Safety first

In the end, the Nasa officials decided: The capsule would be returned unmanned. The flight path was also changed: The "Starliner" flew over and away from the ISS after undocking, making minimal use of its engines - to minimize the risk of a collision with the space station.

The experts from Boeing and NASA disagreed on how high the risk to the health of the crew would have been in the event of a manned return flight. There really were two camps, explained Nasa managers. When re-entering the earth's atmosphere, enormous forces act on space capsules. The heat shields have to withstand temperatures of up to 1650 degrees Celsius.

Analysis of the problems will take months

Numerous sensors on board the capsule were to measure what the conditions would have been like for people inside the "Starliner". The data will be downloaded in a week and the analysis will take some time, said manager Stitch.

The rest of the capsule will also be analyzed and ultimately improved. For example, seals would have to be enlarged and thus made safer. In addition, overheating of the engines is to be prevented in future. The next flight of the "Starliner" is no longer scheduled for February, but has been postponed until August 2025. However, Nasa officials emphasized that they will continue to work with Boeing.

Different company, different spacesuits

Williams and Wilmore, who were stranded in space, are to be brought back to Earth in a different spacecraft: the "Dragon" developed by the private space company SpaceX. NASA is keeping two of the four seats free for them on a mission to the ISS planned for the end of September. However, the return flight is not planned until February - so they will have to wait that long.

The two "Starliner" spacesuits worn by Williams and Wilmore, on the other hand, have already been flown back to Earth, as this Boeing equipment cannot be used in the SpaceX capsule. The new "Dragon" is to carry two SpaceX suits for the two of them.

Plan developed for an emergency on the ISS

But what if something happens on the ISS before the Dragon arrives? According to NASA, two temporary seats have been set up in the cargo hold of the Dragon, which is currently docked there, using items from the space station. These seats also worked without a spacesuit. In the event of an emergency, Williams and Wilmore could board there together with four other ISS space travelers and fly back to Earth.

Otherwise, Nasa managers explained at a press conference in the middle of the week, the two were now working as part of the science and research team on the ISS. "They have left their role as 'Starliner' test pilots behind and are now part of the expedition and work as part of the team on a daily basis," said Stitch. Manager Dana Weigel added that the fitness program had been increased and was now in line with that of other long-term space travelers.

Full commitment in space

In fact, both Williams and Wilmore have a lot of space experience. They have both been on the ISS for long periods before, have completed spacewalks and are familiar with robotics. Since their arrival in June, they have worked a total of more than 100 hours and participated in more than 40 experiments, said Weigel.

In the meantime, the two have also received personal items. The equipment had been sent up especially for the two of them on an already planned flight by the manufacturer Northrop Grumman.

SDA