Discovery is set for the first planned night launch in four years after two technical issues, one with the shuttle’s electrical system and the other with an adhesive used in the ship’s solid rocket boosters, that were resolved of course. But the clouds of concern gathered for Thursday night’s liftoff of the space shuttle Discovery as NASA downgraded launch chances to 60 percent due to bad weather.
The shuttle is expected to lift off at 9.36pm Thursday local time (1336 AEDT Friday).
Concerns about clouds over the Kennedy Space Center and strong winds had put the launch in doubt, but NASA is pressing ahead as scheduled. The primary goal of the 12-day mission is to rewire the International Space Station’s electrical and cooling systems. The seven astronauts are also delivering a 2-ton addition to the station and replacing one of the station’s three crewmembers.
This cannot be denied that on any given day, the launching window is extremely narrow, about 10 minutes, as the Kennedy Space Center falls within the orbital plane of the International Space Station. If conditions do not allow a launching in that window, the opportunity for the entire day is lost.
Weather conditions have to be promising not only here, but also over at least one of the three sites, two in Spain and one in France, that NASA has chosen for emergency landings in case the shuttle cannot reach orbit.
Since the Columbia disaster in 2003, NASA has preferred daylight launches to ensure good photography of the external fuel tank. Foam breaking off the tank at liftoff caused the damage that lead to the Columbia disaster.
Via: NYTIMES
