Avi Blizovsky
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NASA announced on Thursday that the second of the four gyroscopes of the International Space Station Hal has stopped working, but the station and crew members are not in immediate danger.
The fault is in the electrical system and it requires the flight controllers to rely on the two remaining gyroscopes to direct the structure in orbit.
The first gyroscope broke two and a half years ago as a result of a fault in its carrier. Two others are working - the minimum necessary, but one of them has already experienced electrical problems and vibrations in the last year. If another gyroscope is hit, boosters on a cabin of a Russian supply spacecraft attached to the space station and on the space station itself will be used to regain control of the massive structure on the station for about a year.
"It's not an alarm situation for the crew, it's something we're trying to fix," said Mike Suffredini, director of operations for the International Space Station on behalf of NASA. "There are a few more faults that may happen before we can control the vehicle.
The latest problem began to develop at 23:18 p.m. Israel time, less than a day after the new crew, astronaut Michael Finke and cosmonaut Gennady Padalka, arrived at the space station. Five people, including the two former crew members, and a Dutch astronaut from the European Space Agency currently live on the station.
On Wednesday night, the controllers watched the gyroscope slowly fade away. To stabilize the station, the Soyuz engines were activated five times to maintain the desired direction of the station while the other two gyroscopes - wheels rotating at a speed of 6600 revolutions per minute - were activated.
NASA believes that an electrical circuit that is in remote control mode has stopped working. This caused a mechanical problem after the engineers were unable to detect an electrical discharge or erratic movement of the device. The scientists say that under oxidized inside the circuit was broken and led to the malfunction.
The agency is expected to send two astronauts on a four-hour spacewalk to solve the problem. Inside the station there are two spare parts suitable for repairing the power supply system of the gyroscopes, but Superdini estimated that this will not happen in the next month. The astronauts will have to disassemble the screw on the outside of the station and replace the fuse box that serves the gyroscope. Eventually NASA hopes to replace all four gyroscopes with new models.
The repairs are complicated because it is not possible to use the space shuttles, which have been grounded for a year since the Columbia disaster and will not fly again before 2005. The 4-meter-long gyroscopes are too large to fit even the unmanned Progress spacecraft that arrive every six months to resupply the station. The ninth crew is not expected to return to Earth for the next six months. The eighth crew will return to Earth on April 29 together with the Dutch Kuypers that arrived with the members of the new crew. Progress 14, the next supply spacecraft, will lift off to the space station in May.
The previous report: The new crew arrived safely and NASA decided not to switch to one-year shifts in the meantime
For news on CNN
Yadan International Space Station
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