SYDNEY -- U.S. adventurer Steve Fossett drifted across the vast Pacific Ocean on Wednesday, having covered more than one-sixth of the distance needed to become the first person to balloon solo around the world, Reuters reported.

In the early afternoon, the millionaire former stockbroker was about 1,400 km (900 miles) southwest of Fiji after passing New Zealand and Australia's Norfolk Island, where many of the descendants of the mutineers of the bounty live.

"Fossett is in high spirits," his mission controllers in St. Louis, Missouri, said on the expedition's web site at http://www.solospirit.wustl.edu/.

"He is currently using less pure oxygen than he was at the start of his flight," they said.

"He is also acclimatizing quite well."

At about 0300 GMT, Fossett was traveling at nearly 80 kph (50 mph) and his 50-meter (164-foot) high silver balloon, called Solo Spirit, was at an altitude of 7,300 meters (24,000 feet).

There was no sign of the fierce weather that wrecked a previous attempt in 1998 to balloon alone around the world, when Fossett's canopy was torn in a thunderstorm off Australia's northeast coast, sending him plunging 9,000 meters (29,000 feet) into the ocean. He survived unhurt.

His present track has carried him well south of where that incident occurred.

But slower than expected progress since taking off from western Australia on Sunday had meant Fossett's oxygen supplies were at risk of running low towards the end of the southern hemisphere circumnavigation, expected to take from 14 to 20 days.

"We are monitoring Steve's oxygen consumption and looking at strategies to conserve oxygen," mission director Joe Ritchie said, noting that opportunities to fly at lower altitudes depended entirely on atmospheric conditions.

"Steve is on a nice track and one that continues to look good downstream," Ritchie said.

Fossett is expected to travel over the ocean for the next five or six days as he heads toward Chile and Argentina.

The balloon is then expected to drift around the tip of South Africa before heading across the Indian Ocean.

By early Wednesday afternoon, he had covered around 5,000 km (3,180 miles) of the 27,000 to 29,000 km (17,000 to 18,000 miles) needed to complete the trip.

If Fossett makes it, he is likely to land back in Australia, where crowds from desert outback towns and the country music capital of Tamworth waved him on his way as he passed high overhead. But he has not set a landing site.