Cape Canavarel, Fla. ? The seven astronauts who will return the space shuttle to flight arrived in Florida Saturday to begin final preparations for this week’s planned launch.

Their message to the 100 or so journalists and well-wishers gathered at Kennedy Space Center’s shuttle runway was simple: It’s time for Discovery to fly.

“It’s been two and a half years since a crew stood here before you and that’s way too long,” astronaut Andy Thomas said. “And it is definitely time that we went back to flight and back to space.”

Thomas and six crewmates commanded by retired Air Force Col. Eileen Collins are scheduled to lift off at 3:51 p.m. Wednesday on the first shuttle mission since the fleet was grounded in the wake of the 2003 Columbia accident. The countdown for the long-awaited flight is set to start at 6 tonight.

STS-114 Japanese Astronaut Soichi Noguchi, left, shakes hands with Kennedy Space Center Director James Kennedy after arriving at the Kennedy Space Center Saturday in Cape Canaveral, Fla. Seven astronauts are preparing for Wednesday's planned liftoff onboard the Space Shuttle Discovery. NASA is moving forward with preparations for the planned launch of the space shuttle Discovery with weather conditions expected to improve considerably by mid-week as Hurricane Dennis moves away from the Florida peninsula.

Discovery’s astronauts originally had planned to arrive at KSC this morning aboard several small training jets. However, concern about Hurricane Dennis and bad flying conditions between Houston and Cape Canaveral prompted the crew to travel on Saturday afternoon instead aboard a larger Gulfstream business jet.

Collins thanked those at KSC and NASA’s Johnson Space Center in Houston who have spent the past 29 months preparing the shuttle for a safe return to flight. She hailed Wednesday’s planned launch as the start of a new chapter in space exploration.

“I’m very proud of this crew,” Collins said. “And I can tell you that they are very, very prepared and very ready to fly this mission.”

As Hurricane Dennis moves away from the Florida Peninsula, weather conditions at Cape Canaveral are expected to improve considerably by mid-week. Long-range forecasts suggest the weather could be favorable for launch attempts on Wednesday and, if necessary, Thursday.