The launch attempt came after meetings Monday where NASA managers pondered whether a 12 centimeter long crack in the external fuel tank's foam, which caused a seven centimeter piece of foam to pop out on the launch pad, posed a threat to the shuttle during liftoff.
The patch of foam fell off an area that covers an expandable bracket holding a liquid oxygen feed line against the huge external tank. NASA engineers believe ice built up in that area from condensation caused by rain Sunday.
If Discovery gets off the ground Tuesday, it would be the first manned launch by the United States on the country's national holiday, the first launch in almost a year, and only the second launch since the Columbia disaster killed seven astronauts in 2003.
NASA scrubbed launch plans Saturday and Sunday because of weather.
NASA managers decided to go ahead with the attempt Tuesday because they are confident enough foam still is on the bracket to prevent a large piece of ice from forming, they don't believe the area will be exposed to extreme heat during ascent, and the area of foam where the piece dropped was still intactm according to the AP.
Subscribe to Pravda.Ru Telegram channel, Facebook, RSS!