Technical issues delay shuttle flight

CAPE CANAVERAL, Fla. -- The historic next-to-last space shuttle launch was scratched Friday because of mechanical problems, spoiling a visit from the president and dashing the hopes of the biggest crowd of spectators in years, including the mission commander's wounded wife, Rep. Gabrielle Giffords.

NASA hopes to try again Monday to launch space shuttle Endeavour on its final voyage.

President Barack Obama and his family stopped at Kennedy Space Center anyway, where he met briefly with the Arizona congresswoman before visiting with her husband, Mark Kelly and his crew. Giffords, who is recovering from a gunshot wound to the head, arrived in Cape Canaveral on Wednesday to attend her husband's launch.

Giffords had been expected to watch the liftoff in private -- as were the other astronaut families.

Endeavour was fueled and the six astronauts were heading to the launchpad when the countdown was halted, about 3 1/2 hours before the 3:47 p.m. liftoff.

NASA's silver-colored astrovan did a U-turn at the launch control center and returned the astronauts to crew quarters.

It would have been the first time in NASA history that a sitting president and his family witnessed a launch. As a consolation, Obama and his family got an up-close look at Atlantis.

It will make the last shuttle flight this summer as NASA winds up the 30-year program and retires the fleet to museums.

Launch director Mike Leinbach said the next launch try for Endeavour would be Monday at the earliest -- and hinted at an even longer delay. Technicians will have to crawl into the engine compartment to track a suspected electrical short in a power distribution box.

Travel plans for Giffords are still unsettled, said her spokesman, C.J. Karamargin. He said she is waiting until Sunday when NASA should know more about a possible launch date.