CAPE CANAVERAL, Fla. -- The countdown to the launch of space shuttle Atlantis begins on Monday.

The seven-member crew arrived at Kennedy Space Center on Monday morning.

NASA officials said a bent radiator hose that was a concern last week was tested successfully over the weekend.

The hose is part of a cooling system that carries freon aboard the shuttle.

Atlantis has been on the launch pad since November, so the crew is eager to get it off the ground.

Atlantis' launch will kick off NASA's busiest launch schedule since 2002. Five launches are planned, including a flight to the Hubble Space Telescope.

The president announced a budget increase for NASA Monday, but the space agency still doesn't have enough money to fly the shuttle and prepare for the return to the moon, without a five-year gap that'll leave the United States dependent on Russia after 2010 to get U.S. astronauts into space.

"We can't wait to fly," astronaut Steve Frick said.

Preparations are under way at the launch pad Monday.

Technicians slowly closed the doors over the back of the shuttle. Inside the shuttle is a $1 billion lab built in Europe and intended for the space station -- a major expansion of the orbiting outpost. Spacewalking astronauts will attempt to attach it during the mission, a long-awaited event in Europe.

The shuttle weather officer is forecasting a 40 percent chance of good weather.

The countdown clock began ticking at 5 p.m. EST, and launch is set for Thursday at 2:45 p.m.