NASA Postpones Endeavour Shuttle Launch Again

BRUCE WEAVER/AFP/Getty Images(CAPE CANAVERAL, Fla.) -- NASA on Sunday postponed the final launch of the space shuttle Endeavour for the second time, putting it off until at least the end of the week to replace a switch box in Endeavour's engine compartment.

The six astronauts, including Navy Capt. Mark Kelly, the commander of the mission, traveled back to Houston from Florida.

"Things happen fast. We are now all aboard [a plane] for return to Houston. Be back in a few days. More to follow," Endeavour pilot Gregory Johnson said today on his Twitter account. Johnson and Kelly were to be joined on the Endeavour with spacewalkers Mike Fincke, Drew Feustel and Greg Chamitoff, and Italian astronaut Roberto Vittori.

On Friday the space agency pushed back Endeavour's launch because the heater on one of the shuttle's three Auxiliary Power Units -- devices that power the shuttle's speed brakes, elevons and landing gear -- malfunctioned as the astronauts were getting ready to board for liftoff.

The second delay is a disappointment for thousands of spectators who flooded the Florida Space Coast, hoping to catch a glimpse of Endeavour's last launch. Kelly's wife, Rep. Gabrielle Giffords, flew from rehab in Houston to see her husband go on what will probably be his last chance to travel in space.

"Bummed about the scrub!! But important to make sure everything on shuttle is working properly," Giffords' staff said via Twitter on Friday.

Giffords was shot in the head during a shooting rampage in Tucson in January that left six people dead and 13, including Giffords, injured.

The 14-day mission into space, when it happens, will be the last for the space shuttle Endeavour, and could yield new clues to the origin of the universe. The shuttle will carry a $2 billion alpha magnetic spectrometer, an instrument that will be installed on the space station. It could prove or disprove the Big Bang Theory of how the universe was formed.

Copyright 2011 ABC News Radio

NASA Postpones Space Shuttle Launch After Equipment Failure

NASA(CAPE CANAVERAL, Fla.) -- On Friday, NASA postponed the final launch of the space shuttle Endeavour for at least 72 hours to investigate the failure of a key piece of technical equipment.

The space agency said the heater on one of Endeavour's three Auxiliary Power Units -- a device which powers the shuttle's speed brakes, elevons and landing gear -- malfunctioned as the astronauts were getting ready to board for liftoff. The shuttle would not be able to land safely without three healthy APUs.

Technicians will now drain the external fuel tank, go into the bottom of the shuttle and diagnose the problem.

The six astronauts, including Navy Capt. Mark Kelly who commands the mission, were dressed in their orange jumpsuits and headed to the launch pad when the announcement was made. The launch had been set for 3:47 p.m. ET.

The 14-day mission into space will be the last for the space shuttle Endeavour, and could yield new clues to the origin of the universe.

Endeavour's launch has drawn widespread attention because it's the second-to-last for the U.S. space shuttle program, and it's commanded by the husband of Arizona Rep. Gabrielle Giffords, who was shot in the head during a shooting rampage in Tucson in January. Six people were killed and 13, including Giffords, were injured.

Despite her wounds, Giffords travelled to the Kennedy Space Center from her Houston hospital Wednesday. NASA said she would watch the launch in private. It's unclear whether Giffords will now remain in Florida.

The White House said President Obama and the first family would also be there, marking only the third time a sitting president has witnessed a shuttle launch.

Copyright 2011 ABC News Radio