A camera caught the massive bolt as it hit the tower at Florida’s Kennedy Space Centre during an intense thunderstorm, sending 100,000 amps of current through the conductor system.
Nasa later discovered an irregularity in the shuttle’s electrical circuit. An explosive bolt that separates one of the hydrogen venting lead to Atlantis was also left charred by the strike. They also want to check if the solid booster rockets were damaged by the storm.
Nasa launch director Mike Leinbach said he believed the lightning strike, on Friday, was the strongest ever to strike pad 39B. Atlantis was not itself hit. But lift-off, which had been due today, was immediately postponed by at least 24 hours so that engineers could carry out a thorough safety check.
Atlantis is sister ship to Discovery which returned to space last month carrying British astronaut Piers Sellers after the fleet had been grounded for a year. The crew of mission STS-115 consist of Commander Brent Jett, Chris Ferguson, Heidemarie Stefanyshyn-Piper, Joseph Tanner, Daniel Burbank and Canadian Steve MacLean.
Nasa are keen to launch regularly in future to complete building of the International Space Station before the shuttle fleet is retired in 2010. During the mission, a major new truss and a second set of solar arrays to generate power from sunlight will be added to the orbiting outpost.