NASA has delayed Sunday's planned launch of the space shuttle Atlantis for 24 hours to assess possible damage from a lightning strike on the ship's Florida launch pad, the US space agency said on Saturday.
Postponement of the launch until 3:04 pm EDT (1904 GMT) on Monday would give managers more time to analyse data from shuttle systems and ground support equipment that may have been affected by the lightning bolt that struck on Friday, NASA spokesman Bruce Buckingham said.
There was no apparent damage from the lightning bolt which struck a thick wire at the top of the shuttle's seaside launch pad at about 2 pm EDT (1800 GMT) on Friday, said Jeff Spaulding, a NASA launch supervisor, in a news conference on Saturday.
The wire is part of the launch pad's lightning protection system. "So far it looks favourable," said Spaulding, adding that equipment evaluations remained under way.
Forecasters on Saturday predicted a 60 percent chance that weather would delay Sunday's liftoff, but the outlook for Monday is for just a 20 percent chance of a weather-related delay.
Any rain when the shuttle blasts off from its launch pad could damage the spaceship's heat-shielding tiles, and a lightning strike could knock out the computers that control the ship. Even some kinds of thick, high clouds make launch precarious.
Atlantis' mission is the first with a primary goal of working on construction of the space station since the 2003 Columbia accident, and another accident or serious problem would likely ground the shuttles permanently. NASA is also keeping a sharp eye on Tropical Storm Ernesto.