Shuttle Discovery launch

NASA successfully launched the space shuttle Discovery Tuesday, after two previous launches were scrubbed due to bad weather in the southeastern U.S. state of Florida.  The launch begins the latest mission to help finish the development of the international space station.  It also allowed NASA to breathe a sigh of relief, after more concerns arose about foam insulation on the shuttle.

Discovery blasted off the launch pad Tuesday afternoon, on its way to a rendezvous with the International Space Station. Plans call for a 12-day mission to deliver supplies to the space station and repair some of its equipment. The flight began despite concerns about foam insulation possibly tearing off during launch.

Monday, NASA engineers found a 10-to-12 centimeter crack in the external fuel tank's foam insulation.  They also found a seven-centimeter piece of insulation had broken off a bracket holding a fuel line in place.

Insulation problems have plagued the shuttle program since the loss of Discovery’s sister ship Columbia in February of 2003. That spacecraft broke apart during re-entry over the southwestern U.S. state of Texas, killing the entire crew.

Investigators determined a piece of foam insulation from Columbia's external fuel tank broke off during launch, creating a hole in the shuttle's heat shields.

NASA engineers put a camera on a long pipe to give them a closer look at the problem area. They eventually decided to go ahead with the launch.

Bill Gersteinmaier, NASA's Associate Administrator for Space Operations, explains. "Those views show the foam is structurally intact, it shows that the gaps that are supposed to be there between the two pieces of remaining foam are clear of debris, there's no loose foam in there, it all looks fine and the structure is in good shape."

NASA grounded its shuttle fleet following the Columbia tragedy. It spent more than one billion dollars trying to correct insulation problems. Tuesday's launch was just the second since Columbia. Discovery flew about a year ago. The shredding of foam was greatly reduced on that mission -- but still occurred. NASA responded by removing more than 15 kilograms of foam and making other changes.

Discovery's latest mission is crucial to NASA, because President Bush has stated his goal to retire the shuttle fleet by the year 2010.

NASA Administrator Michael Griffin overruled a recommendation by two NASA safety inspectors against Discovery's launch. He said Tuesday that NASA’s mission must go forward.  "It's an important step toward completing the international space station. We're halfway done. We have 400,000 pounds of hardware on orbit, we have another 400,000 plus to go."

The first of 16 additional shuttle flights to complete construction of the space station could fly as soon as late August -- if Discovery's current mission is a success.