CAPE CANAVERAL, Fla. - With wounded U.S. Rep. Gabrielle Giffords on hand to watch, the space shuttle Endeavour is poised to give the work week a roaring and historic start Monday morning, overcoming wiring problems that grounded it last month.

Giffords' arrival Sunday afternoon included a quick fly-by of Endeavour on the launch pad, then she bid Kelly goodbye at the bucolic beach house used by shuttle crews before launch.

"Gabrielle is excited for tomorrow's launch. Do you plan to see history in the making?" her staff tweeted. Later, her staff added: "Gabrielle & Mark said goodbye during visit before launch. Beach House made for picturesque setting."

NASA officials said conditions -- from weather to technical issues -- couldn't look much better for the scheduled 8:56 a.m. (1256 GMT) launch Monday.

Giffords, travelling on a NASA jet with the family of pilot Gregory Johnson, arrived shortly after the protective structure that surrounds Endeavour was moved out of the way -- a milestone in launch preparations that allows fueling to begin late Sunday night.

NASA was so ready to get the flight off the ground that they moved the protective scaffolding 15 minutes earlier than planned.

There was only a 30 per cent chance of a weather delay, mostly because of crosswinds.

The conditions were far different from last month's futile launch attempt. The protective cover wasn't removed for five hours because of storms, and the launch was scrubbed because of an electrical problem.

Because of the early morning launch, Endeavour's crew will be working odd hours, going to bed when most people are ready to eat dinner. Just before 5 p.m. Sunday, Endeavour astronaut Mike Fincke tweeted that he was going to sleep and then promised an early morning update to his more than 10,000 Twitter followers: "I plan to tweet until they take my phone away!"

Endeavour's pilot, Johnson, then tweeted that he couldn't sleep: "I'm a little too excited to hit the rack just yet."

NASA is expecting slightly smaller crowds -- 400,000 people instead of 750,000 people -- for the second attempt. The media horde is also slightly thinned -- even though the April attempt was on the same day as the royal wedding -- but includes television anchors such as Katie Couric of CBS, said NASA spokesman Bob Jacobs.

President Barack Obama and his family were among those who travelled to Kennedy Space Center last month hoping to see a launch. He met with the astronauts and visited with Giffords, but won't return Monday.

With the story of Giffords remarkable recovery from the January shooting having been the focus of media attention in April, now more people are paying attention to the other parts of Endeavour's planned 16-day mission. The shuttle's main goal is to haul a $2 billion astronomy and physics experiment to the international space station.

This is also the next to last flight for the 30-year-old space shuttle fleet. And it is the final flight of the shuttle Endeavour, NASA's youngest orbiter, which has flown 116.4 million miles (187.3 million kilometres) in 24 previous flights.

Giffords was wounded in the head in a mass shooting in January in her Tucson, Arizona, district that killed six people. Doctors have cleared her to travel to see the launch. She came for the April attempt, flew back to Houston to resume her rehabilitation work and even had dinner out with her husband.

People in campers and cars started lining up Sunday afternoon for the best viewing spots to see Endeavour lift off.

Along the Indian River lagoon in Cape Canaveral, Gary and Gail Isackson of Kansas City, Missouri, were looking forward to seeing the shuttle but worried that they might be chased off one of the prime viewing spots by police.

"I didn't spend all day sweating with love bugs to miss this," Gary Isackson said.

Beverly Haller of Spring Hill, Florida, and Owosso, Michigan, said she wanted to see Endeavour's last flight and her first shuttle launch. She worried that if the shuttle didn't launch Monday, she'd miss her only chance because she won't be able to see Atlantis in July.

"This is it," she said. "I mean I've got to see it. Don't over sleep anybody."