Space Shuttle Endeavour Launch Postponed

The much-awaited final launch of the space shuttle Endeavour has been put on hold for 48 hours. Mission STS-134's launch was to be attended by Shuttle Commander Mark Kelly's wife Rep. Gabrielle Giffords, President Obama, and an estimated 700,000 spectators. It was scrubbed due to an issue with "Auxiliary Power Unit 1 heaters." Up until minutes ago, the mission was deemed "Go" by NASA, and a launch time of 3:47 p.m. EDT was planned. Please refrain from sending hate mail to Auxiliary Power Unit 1, it tried its best. More info after the jump. [@NASA]

UPDATE: From BoingBoing, Shuttle Launch Director Mike Leinbach's comments about the scrubbed launch:

"A thermostat on one of the fuel lines, one of the heater units, failed. We tried to get the line to cool down, to see if thermostat would kick in, and tried other methods to activate -- but failed. We have a hard failure. There was another heater also exhibiting funny behavior. We believe we have a problem in the LCA, load control assemblies, switch box. Maybe a problem in the box, or in the line leading in to the box, or out of the box. But we didn't want to commit to flight with only one of the heaters functioning. Need to be able to heat the fuel. Probably tomorrow afternoon they'll get hands on the assembly. Once we can get in to the avionics bay where the LCA exists, we can do troubleshooting, see if we need to change out that box. We've declared a minimum of 72 hours. Today the orbiter's not ready to fly. We will not fly before we're ready."

Space Shuttle Endeavour STS-134 launch: BB liveblog on-site, SpaceFlightNow webcast with Miles O'Brien [BoingBoing]

[ngreene@villagevoice.com / @nickgreene]