» Top 10 IT Disasters of All Time
Who would have thought that such a trivial coder’s mistake could blow up rocket ship?
3. The explosion of the Ariane 5 (1996)
In 1996, Europe’s newest and unmanned satellite-launching rocket, the Ariane 5, was intentionally blown up just seconds after taking off on its maiden flight from Kourou, French Guiana. The European Space Agency estimated that total development of Ariane 5 cost more than $8bn (£4bn). On board Ariane 5 was a $500m (£240m) set of four scientific satellites created to study how the Earth’s magnetic field interacts with Solar Winds.According to a piece in the New York Times Magazine, the self-destruction was triggered by software trying to stuff “a 64-bit number into a 16-bit space”.
“This shutdown occurred 36.7 seconds after launch, when the guidance system’s own computer tried to convert one piece of data — the sideways velocity of the rocket — from a 64-bit format to a 16-bit format. The number was too big, and an overflow error resulted. When the guidance system shut down, it passed control to an identical, redundant unit, which was there to provide backup in case of just such a failure. But the second unit had failed in the identical manner a few milliseconds before. And why not? It was running the same software,” the article stated.