MOSCOW (Reuters) - The crew of the International Space Station (ISS) could have a rough return to Earth because their re-entry capsule has the same glitch that caused problems on the last two landings, a Russian space industry source said.
Russia’s space agency would not comment on technical problems but said the Soyuz-TMA capsule was safe to carry Russian cosmonauts Sergei Volkov and Oleg Kononenko and U.S. space tourist Richard Garriott back from orbit in October.
Concerns have been raised about the safety of the Soyuz because the last two re-entries have not gone to plan: they were so-called “ballistic” landings where the entry into the atmosphere was steeper than usual.
In the last landing in April, the crew of U.S. astronaut Peggy Whitson, South Korean Yi So-yeon and Russia’s Yuri Malenchenko landed about 420 km (260 miles) off course and they were subjected to twice the expected gravitational forces.
The space industry source, who did not want to be identified, told Reuters faulty bolts were suspected of causing the last two “ballistic landings” and they are also fitted on the re-entry capsule now docked at the ISS.
“There are explosive bolts which keep two modules attached to Soyuz capsules,” the source said. “They are supposed to go off right before the entry into the Earth’s atmosphere.”
“For some reason this didn’t work (on the previous two re-entries), although the unseparated modules fell off eventually. What is bad is that another Soyuz-TMA is believed to have this faulty device and is docked at the ISS for the return trip,” he said.
Roskosmos, the Russian space agency, declined to comment on any technical faults with the Soyuz. An inquiry has been launched into the problems with the last two landings, but its findings have not been made public.
Roskosmos spokesman Alexander Vorobyov said even if there was a repeat of the “ballistic” landings, the crew would be safe “due to the high reliability of the Soviet-era spacecraft”.
Vorobyov said he had spoken to Vladimir Solovyov, flight director for the Russian section of the ISS, “and his opinion is as follows: this Soyuz is indeed safe for return”.
“He said that in any case, even in the event of a ballistic landing, these explosive bolts burn down due to high temperatures (on re-entry), and then the descent -- even if is not so gentle -- won’t be life-threatening for the crew.”
U.S. space agency NASA has said it has confidence in the Russian space program, and that there was still time to fix any problems with the Soyuz before it was used next.
Space sources have said when the modules failed to separate from the capsule on the last two “ballistic” re-entries, the capsule was pulled off course and tilted so that its heat-resistant shield was not facing the direction of travel.
As a result the capsule heated up and its antenna burned, sources in the Russian space program have said.
South Korea’s first astronaut Yi So-yeon said after April’s rough landing she thought she might die. She suffered back problems and had to undergo treatment at home.
Space tourist Garriott, a 46-year-old video game designer, wrote on his blog at www.richardinspace.com that he was closely following “possible hardware concerns” with the Soyuz.
“I am confident every effort is being applied to diagnose this issue,” he wrote. “This issue will be resolved and I have every confidence in the ship, the crew and the Soyuz team.”
Editing by Mark Trevelyan