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Last Updated: Monday, 18 June 2007, 10:29 GMT 11:29 UK
ISS computer woes concern Europe
By Irene Klotz
Cape Canaveral, Florida

Artist's impression of ATV (Esa)
The ATV will launch to the ISS early next year

The same computer systems that crashed aboard the International Space Station (ISS) last week are also incorporated into two new European contributions to the orbiting outpost due to be launched around the year's end.

The Columbus laboratory is scheduled to fly on shuttle Atlantis' next flight in December.

The Automated Transfer Vehicle (ATV) - a huge supply vessel - will make its maiden voyage atop an Ariane 5 rocket early next year.

As a result of the ISS's computer shutdown, which raised concerns that the outpost might have to be temporarily abandoned, the European Space Agency (Esa) has now launched an investigation to see if similar problems could hit the systems incorporated into Columbus and the ATV.

The ISS's primary computers, which are located in the Russian command module Zvezda, were supplied by EADS Astrium Space Transportation in Bremen, Germany, under contract to the European Space Agency.

In exchange, Esa received equipment from Russia to dock the ATV at the space station.

Gyro overload

Esa set up a team that joined the around-the-clock, multi-national effort to recover the ISS computers and figure out the cause of the crash.

"The team will look at the relevance of this situation to the ATV (which has identical computers) and Columbus (which has similar machines), to ensure that corrective action, if any, is taken well before flight of the two European elements," the agency said in a statement.

Astronauts on spacewalk (Nasa)
The station's changing shape may be at the root of some problems
So far, engineers have not been able to pinpoint the specific cause of the computer malfunction, which shut down the rocket-steering system the station needs to correct its alignment in space so that solar wing panels can track the Sun for power.

The thrusters are also used to keep the station properly positioned for warming or cooling various elements, and to point antennas toward Earth for communications.

Most of the time the station uses the US gyroscopes, which spin to maintain position, but the thrusters kick in to counteract stronger motions, such as those caused by the attachment and release of visiting spaceships, or when the station has to be manoeuvred around a piece of orbital debris.

In addition, the computers also automatically control life-support equipment, though these can be manually operated as well.

Field change

The computer problems started as spacewalking astronauts from shuttle Atlantis last week hooked up a new metal beam that holds a huge pair of solar wings.

ISS

The US space agency (Nasa) and Russian engineers believe the most likely cause of the crash was a change in the electrically charged plasma field the station flies through as it orbits 350km (220 miles) above Earth.

The theory is that the plasma field shifted when the station's shape changed with the addition of the new truss segment.

"As the station gets bigger, this potential will continue to grow," Nasa's space station programme manager Mike Suffredini told reporters.

"The Russians have noted some changes in their systems as we have grown," he added.

"I think we're going to find there's some sensitivity to the noise that is created as we change the space station."


SEE ALSO
Astronauts end fourth spacewalk
18 Jun 07 |  Science/Nature
Repairs ease space mission woes
16 Jun 07 |  Science/Nature
Computer crash hits space station
14 Jun 07 |  Science/Nature
Nasa to carry out shuttle repairs
12 Jun 07 |  Science/Nature
Astronauts end second spacewalk
14 Jun 07 |  Science/Nature
Shuttle heads for space station
09 Jun 07 |  Science/Nature
Europe set for bigger station role
17 Jul 06 |  Science/Nature
In graphics: Space Station
30 Apr 07 |  Science/Nature

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