Endeavour flight has high-profile cargo, commander

Mission Commander Mark Kelly climbs from his T-38 jet trainer as he arrived with the crew of space shuttle Endeavour's mission STS-134 at the Kennedy Space Center in Cape Canaveral, Florida, April 26, 2011.

CAPE CANAVERAL, Florida (Reuters) - Pioneering science and celebrity attention will give added lift on Friday to U.S. space shuttle Endeavour's final launch, in which the shuttle commander and his convalescent congresswoman wife will be in the spotlight.

President Barack Obama and his family will be at the Kennedy Space Center to watch Endeavour blast off at 3:47 p.m. EDT (2047 GMT) in what will be the second-to-last flight of space agency NASA's 30-year shuttle program, which is being phased out this year.

Watching too will be U.S. Representative Gabrielle Giffords, an Arizona Democrat who is recovering from a near-fatal shooting in January and whose husband, Mark Kelly, commands the six-member Endeavour crew on its two-week maintenance mission to the International Space Station.

"It is exciting to have the special guests," said NASA's Jeremy Graeber. But he added this would not be a distraction to the 134th shuttle mission, which will go ahead at the scheduled time if technical and weather conditions allow.

"We're very aware of the fact that we've got a job to go do," Graeber said.

Adding to the media buzz surrounding Endeavour's final launch is the $2 billion device it will be carrying which scientists hope can shed new light on knowledge of the universe by studying its little-known "dark matter".

The seven-ton Alpha Magnetic Spectrometer or AMS will analyze particles in high-energy cosmic rays, the first detailed look at this type of matter in space.

Doctors have given the recuperating Giffords a green light to attend the shuttle launch in Florida. She was shot in the head on January 8 outside a Tucson, Arizona, grocery store when a gunman opened fire, killing six and injuring 13 people.

The trip to see the departure of her husband and his colleagues marks Giffords' first extended outing from hospital during her recovery. She was due in Florida on Wednesday.

After the shuttle launch, Giffords will return to Houston to continue her rehabilitation,

"It's something that she's been looking forward to for a long time," said husband Kelly, who rejoined the crew in early February after a month's absence to oversee his wife's care.

Two days after Endeavour's launch, the shuttle is expected to arrive at the orbiting space station for a visit lasting 10-12 days. Sixteen nations, including Russia, are partners in the $100 billion space station project.

PROBING ORIGIN OF UNIVERSE

In addition to installing the Alpha Magnetic Spectrometer to the outside of the station, the Endeavour crew plans to conduct four spacewalks to help prepare the outpost for operations after the shuttle program ends.

They will use robotic cranes to install the AMS.

Telescopes and other space observatories, like the Hubble Space Telescope, measure light rays, not charged particles, which will be scrutinized by the new device.

Scientists expect to learn about exotic forms of matter that cannot be studied on Earth and perhaps answer long-standing questions about how the universe formed.

Endeavour also will deliver a platform loaded with large spare parts, in hopes of keeping the station running for at least the next 10 years.

On Endeavour's return, NASA will shift focus to the launch of shuttle Atlantis on the 135th and final flight, a supply run to the station currently targeted for liftoff on June 28.

Smaller cargo and crew supplies will be flown to the station on Russian, European, Japanese and eventually U.S. commercial cargo ships. With the U.S. shuttle fleet's retirement, Russia is taking over crew ferry flights, a service that currently costs the United States $51 million per person.

The price is going up to $63 million a seat in 2014. NASA hopes to break the Russian monopoly by helping U.S. private firms develop the capacity to fly people in space. It last week announced $269 million in partnerships with four firms.

Prime shuttle contractor United Space Alliance has told its 5,600 workforce half will be out of a job by early August.

The shuttles will be put into retirement. Discovery, which completed its last mission in March, will be on display at the Smithsonian National Air and Space Museum's Steven F. Udvar-Hazy Center outside Washington. Endeavour is promised to the California Science Center in Los Angeles.

Only Atlantis will stay near the launch site. Its retirement home is the Kennedy Space Center Visitor Complex.

(Editing by Pascal Fletcher)