NASA's heavy-lift balloon, which took off from Wanaka airport in New Zealand last month, has come down early over central Australia because of a suspected leak.
The 4,000 kg 'super pressure' balloon, which is 90 metres in diameter, was meant to stay aloft 34 km above the earth's surface for 100 days but its flight was ended, after just 32 days, earlier this week, NASA has confirmed.
"While we hoped for more days at float, we exceeded our pre-established minimum success criteria of 10 days by threefold in the balloon's most demanding test yet," the balloon programme's chief Debbie Fairbrother was quoted as saying.
Controllers detected a leak developing and issued flight termination commands. It fell over a remote area near the Queensland and New South Wales (NSW) border just east of Sturt National Park.
A map of the balloon's progress showed it had been flying over the Southern Ocean before it tracked north to land, media reports said.
The flight was a test run to assess the viability of using such balloons in NASA's research programme after 15 years of development, and of Wanaka's suitability as a permanent launch site.
If Wanaka is confirmed as a launch site, future balloons will carry equipment to assess the effects of cosmic rays on the atmosphere and investigate the origins of the universe.