After sealing the crack in a soyuz space capsule, experts research the cause of the leak. The capsule docked to the international space station ISS was probably hit by a micrometeorite, said a representative of the russian space agency roskosmos.
But other possibilities should also be investigated. Material problems could not be ruled out. German astronaut alexander gerst is also on board the ISS.
In the night to thursday in the russian capsule there was a crack of about two millimeters in size. He had triggered a pressure drop in the space station, which orbits the earth at a height of about 400 kilometers. The incident was not dangerous for the crew, roskomsos stressed. The spacewalkers had sealed the leak with a special adhesive-transeted cloth. "The air pressure is normal, no further cracks were found," it said.
German space expert ulrich walter doubted that a meteorite caused the damage to the capsule. "Maybe there was a production error and the russians didn’t work properly," he told "spiegel online". Cracks or holes could also be caused by mechanical stress in space.
In his opinion, the previous sealing is not sufficient to permanently seal the crack. "A rag is not quite airtight after all. It will keep the coarse airflow out, but it will still leak a little," said walter. Further repair work is therefore urgently needed.
Roskosmos stressed, however, that the leak was completely sealed. The crew has been checking for air leaks and other cracks in the capsule. This can be clearly ruled out, the agency said. No ejector deployment was necessary. But new covers were tested.
Normal ISS operations should resume as early as friday. The soyuz capsule, which is docked with the ISS and is supposed to bring the astronauts back to earth, can continue to be used without any problems, roskosmos explained.
"Yesterday showed again what our emergency training is good for," gerst tweeted. Together with the crew and the space agencies on earth, the small leak was quickly found and sealed. The astronauts will be meticulously prepared for possible accidents prior to their mission.
Leaks and cracks on the ISS’s aft wall are not uncommon. In 2014, a tiny splinter had penetrated a solar sail and narrowly missed an important ammonia-carrying tube of the solar module. The ISS has also had to dodge approaching space debris, such as parts of discarded satellites, on several occasions.