The US space shuttle Atlantis finally landed on earth. However there were tense moments in the last few days of the mission with the computers in the International Space Station (ISS) failing to reboot as also the damage in the shield of the shuttle. Fortunately, both these faults have been repaired successfully within the shortest possible time.

However, for the computer failure at ISS, there are a few concerns which will have to be addressed. The problems arose in the six computers supplied by the European Space Agency (ESA) to the Russian part of ISS called Zarya. These command and control computers were responsible for the control and navigation of the space station in orbit as also for running systems that remove carbon dioxide and ensure fresh oxygen for the crew. These computers have been running fine since the year 2000, when it was first deployed. The real cause of the glitch is yet to be ascertained but it is suspected that a new solar panel that was fitted to the station could have been the cause. The ISS repair crew, which included members from NASA along with the Russians, had actually bridged a

protection circuit which got four of the six computers working. They also

reloaded the operating software. Further, as a precaution, all spare computers and computers meant for the ESA’s Automated Transfer Vehicle (ATV) for launch early next year, were checked.

Although back-up systems had been worked out, including the worst-case scenario of all astronauts abandoning the station, the incident has highlighted the criticality of having computers available and functioning. In most countries which have their own the space programmes, the security and availability of computer systems is of prime concern. They also demand strong back-up and disaster recovery procedures. Also vital is the ability of computer engineers from various countries to handle different operating

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