Countdown begins for next-to-last shuttle launch

CAPE CANAVERAL, FL Endeavour is set to blast off Friday afternoon on its final voyage. It will be the next-to-last space shuttle mission.

Navy Capt. Mark Kelly and his crew flew into Kennedy Space Center early Tuesday afternoon. The countdown began about an hour later.

Speaking on behalf of his five crewmates, Kelly expressed pleasure at seeing the astronauts' wives and children, who flew in a little earlier and gathered nearby.

Giffords was not among the crowd. She remained behind in Houston, where she is undergoing rehabilitation for a gunshot wound to the head. She was attacked Jan. 8 in her Tucson, Ariz., hometown.

"I'm personally looking forward to my wife, Congresswoman Gabrielle Giffords, getting here pretty soon, to be here in time for our launch on Friday," Kelly told the crowd of family members and journalists.

"It's something she's been looking forward to for a long time," he said. "She's been working really hard to make sure that her doctors would permit her to come. She's more than medically ready to be here, and she's excited about making this trip."

Her doctors announced Monday that she could travel to Florida. Kelly was greeted Tuesday by his identical twin, astronaut Scott Kelly. Both wore turquoise "Gabby" wristbands.

President Barack Obama and his family also will attend the liftoff.

NASA test director Jeremy Graeber said the presidential visit -- and Giffords' presence -- will not distract the launch team. It's exciting, though, to have so many people coming for Endeavour's final takeoff, especially first-time guests, he said.

Forecasters put the odds of good launch weather at 80 percent. Launch time is 3:47 p.m.

Endeavour will carry a $2 billion particle physics experiment to the International Space Station along with a load of spare station parts.

The 30-year shuttle program will end this summer with the flight of Atlantis.