The space shuttle Endeavour STS-134 sits on launch pad 39A as the suns sets at the Kennedy Space Center in Cape Canaveral, Florida May 15, 2011. Endeavour and its six-man crew will deliver a unique astronomical and particle physics experiment to the orbiting outpost. [Photo/Agencies]

CAPE CANAVERAL, Florida - With wounded US 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.

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"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 am (1256 GMT) launch Monday.

Giffords, traveling 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 percent 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 pm 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 traveled 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.