Millionaire adventurer Steve Fossett (search) took off Monday night on his attempt to become the first person to complete a solo trip around the world in an airplane without making a single stop.

Fossett, the first person to circle the globe solo in a balloon, launched his GlobalFlyer (search) from the Salina Municipal Airport shortly before 7 p.m., beginning a 66-hour journey by climbing northeast into a darkening sky.

Hundreds of spectators, braving a bitterly cold wind, gathered along the two-mile runway to watch the takeoff. Fossett hoped to return to Salina on Thursday morning.

The 23,000-mile flight had already been postponed several times because of shifting jet stream patterns or weather at the airport.

"I'm a bit nervous about takeoff," said Fossett, 60, who has logged about 30 hours in the jet-powered aircraft. "I will be the ultimate test pilot. I have a lot to worry about. It's a major endeavor."

Financed by Virgin Atlantic founder Sir Richard Branson (search), it would be the first solo flight around the world without stopping to refuel.

Branson watched the takeoff from the side of the runway with Fossett's wife. "It was obviously an emotional moment and the most dangerous part of the journey," he said. "It was an enormous relief when it actually came off the ground."

Aviation pioneer Wiley Post made the first solo around-the-world trip in 1933, taking more than seven days and stopping numerous times along the way. The first nonstop global flight without refueling by a duo was made in 1986 by Jeana Yeager and Dick Rutan, brother of Burt Rutan, designer of the GlobalFlyer.

Besides the nonstop record, Fossett will attempt to break seven other aviation records, including the longest flight by a jet aircraft. The current record is more than 12,000 miles, set by a B-52 bomber in 1962.

Mission control director Kevin Stass said Fossett would fly over Chicago, Detroit and Canada before heading across the Atlantic late Monday night. The route would then take him over Africa, the Middle East, India, China and the Pacific Ocean.

The flight plan was adjusted once more later Monday after Algeria closed a portion of its airspace, mission control director Kevin Stass said. The change, he said, would slightly reduce the overall length of the flight and save some of the 18,000 pounds of fuel aboard the single-engine jet.

Fossett planned to fly at an average speed of 287.5 mph and rely on the jet stream to stretch his fuel. The GlobalFlyer will have about 15 percent extra fuel to allow for weather conditions or other changes to the flight plan, said Jon Karkow, chief engineer for the flight.

There was a risk the fuel could freeze from flying in the cold at altitudes of 52,000 feet for such a long time.

Fossett will survive on diet milkshakes. "I just picked a bunch of flavors off the shelf at the store," he said.

Branson planned to follow Fossett in a chase plane for the first day of the flight and on the last leg. He gave Fossett his wristwatch, complete with emergency beacon device, to wear for the flight.

"We want you and [the watch] back in one piece at the end," Branson quipped.

Fossett became the first to fly a balloon solo around the world in 2002 after nearly dying twice in six attempts to set the record. He has also tried to break the world gliding altitude record for the past four years in New Zealand but has failed because of poor conditions.