The six astronauts talk to reporters after arrival on Thursday. Photo: NASA

The astronauts have arrived and NASA is ready to begin the countdown for the first human space adventure of the new millennium.

Launch of space shuttle Endeavour on an 11-day radar mapping mission of Earth is slated to begin at 1747 GMT (12:47 p.m. EST) on Monday. The available launch window extends for two hours and two minutes that day.

Preliminary weather forecasts show a favorable 70 percent chance of good conditions.

Veteran shuttle commander Kevin Kregel and his five other crewmates flew from Houston to Kennedy Space Center Thursday, touching down just after 1700 GMT (12 noon EST) in their four T-38 jets.

"I'm just really happy to be here. It is a beautiful day. We are looking forward to doing this mapping mission. Hopefully, we will have a beautiful day like today and the winds will die down on Monday," Kregel told reporters gathered at the runway.

The astronauts will spend the next few days reviewing flight plans, undergoing medical checks and spending time with their families.

The shuttle launch team will gather in Firing Room No. 3 of the Complex 39 Launch Control Center at 2200 GMT (5 p.m. EST) on Friday in advance of starting the three-day countdown. Clocks will begin ticking at 2230 GMT (5:30 p.m. EST).

Endeavour's flight will carry a sophisticated radar system to map a majority of the Earth's topography.

"The science on this flight is going to be spectacular," payload commander Janice Voss said to reporters Thursday. "The 3-D map of 80 percent of the surface of the Earth we think is going to be really a great product to bring back for everybody on this planet."

The astronauts are divided into two shifts, the Red Team and Blue Team, to conduct round-the-clock, 24-hour mapping operations once in space.

The Red Team is comprised of Kregel, flight engineer Janet Kavandi and German astronaut Gerhard Thiele. The Blue Team is led by pilot Dom Gorie, with Voss and Japanese astronaut Mamoru Mohri. The Red Team will be responsible for deploying the 200-foot long antenna mast during the early hours of the mission.