MOSCOW -- Initial analysis of data from flight recorders installed on board the Soyuz-TMA-1 that returned the Expedition Six crew to Earth on May 4 indicates that a technical glitch rather than human error caused the capsule to veer off and land far from the designated area on the wind-swept Kazakh steppe, a senior Russian space industry official said.
Soyuz-TMA-1 was shipped on May 6 to Rocket Space Corporation Energia in Korolev, where the spacecraft was designed and built, so engineers can retrieve data from the flight recorders. It will take some three to four days to analyze the data and possibly pinpoint the glitch, a senior Energia designer told SPACE.com.
The designer, who asked not to be named, said in a May 8 phone interview there could have been a glitch in Soyuz-TMA's control system or computer that could have led to the ballistic trajectory descent. In addition to being able to accommodate larger size crew members, the Soyuz-TMA has an advanced computer and control system compared to its predecessor Soyuz-TM.
Having accessed the Soyuz-TMA-1, Energia engineers analyzed the audio records that contain every single word which Soyuz-TMA-1's crew of Russian cosmonaut Nikolai Budarin and U.S. astronauts Ken Bowersox and Don Pettit pronounced during the descent, the Energia designer said.
The crew members are required to describe out loud each command they enter during their flight back to Earth, said the designer, who asked not to be named. The audio records indicate the crew played by the book. Nonetheless, a thorough analysis of the flight record data will be done to prove whether it was a human error or, indeed, a technical glitch that led to the steep descent, he said.During a May 6 press conference in Star City, the Expedition Six crew said they did not believe they had entered any wrong commands.
One minute before the controlled descent was to have started, Soyuz-TMA's control system activated the so-called ballistic trajectory mode and sent the capsule into a steeper and far less comfortable dive to the Earth, Budarin said.
During the rough descent, the crew lost contact with mission control after the communications antennae got torn away along with the parachute stripe it was attached to, Budarin said.
As a result of this loss of communications, Russian and U.S. space officials and the crew's relatives and friends endured an uneasy two hours before the rescue planes finally located the trio and their capsule nearly 325 miles (500 kilometers) away from the initially designated area in Kazakhstan.
NASA administrator Sean O'Keefe said the wait gave rise to memories of the Feb. 1 loss of shuttle Columbia and its seven member crew.
Russian space chief Yuri Koptev, meanwhile, noted that O'Keefe's decision to travel to Russia for the landing was symbolic.
"This is evidence of the fact that Russia and U.S. are united in this project and that both countries carry the main burden of this program," Koptev told journalists at a post-landing press conference he held jointly with O'Keefe on May 4.
O'Keefe and Koptev held a separate meeting in Moscow on May 5 and agreed that the meeting of chiefs of space agencies involved in the International Space Station (ISS) project should be postponed from May to September, Sergei Gorbunov, spokesman for the Russian Aviation and Space Agency said.
The two space chiefs also agreed that Russian space companies should be allowed to participate in NASA contracts, according to Gorbunov.
Speaking of the Soyuz TMA-1 descent, Energia president Yuri Semyonov told reporters in Chkalovsky, Moscow region, on May 4 that the capsule's onboard computer "simply went nuts" causing the spacecraft to go into an uncontrolled ballistic dive towards the Earth.
In remarks broadcast by Russian television, Semyonov said one of the crew members "pushed a wrong button." Semyonov said the button is used to activate a system that automatically steers Soyuz-TMA towards ISS for docking.
The senior Energia designer confirmed that one of the two US astronauts did "push a wrong button" when Soyuz-TMA was still in orbit, but insisted that this error could not have any impact on the re-entry.
The Energia designer said the astronaut -- whom he refused to identify -- entered a command into the Soyuz-TMA's Argon onboard computer to activate the Kurs system used to automatically steer the craft towards the space station for docking.
The error was made some 30 minutes before the craft ignited its engines to slow down and enter the atmosphere, the Energia designer said. The Flight Control Center in Korolev noticed the error and corrected it.
He noted that Argon is located in the so-called instrument compartment which separates from the descent capsule and remains in orbit as debris while the capsule itself goes down. Thus, a wrong command entered into Argon could not have had any impact during the re-entry as the capsule has its own control system.
The May 4 landing was the first time a Soyuz-TMA was used to bring a crew back to Earth. Its predecessor Soyuz-TM's have logged dozens of successful controlled landings. There was only one descent along the rough ballistic trajectory of this craft, but that was an unmanned craft launched for test purposes, according to the Energia designer
Also two crews of the Soviet-era Salyut space stations went down along the ballistic trajectory in their Soyuz capsules, which are predecessors of Soyuz-TMA, in April 1979 and May 1980.
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