Nasa has successfully launched a super pressure balloon from Wanaka Airport to conduct near-space scientific investigations.
While winds looked set to thwart plans early this morning, conditions eased, allowing the launch about 11.30am.
Watch a livestream of the launch here
Tuesday's launch marks the fifth attempt to get the massive balloon airborne, with previous bids thwarted due to bad weather, Nasa said.
Long-duration balloon flights at constant altitudes play an important role in providing inexpensive access to the near-space environment for science and technology.
The 532,000 cubic metre balloon is expected to circumnavigate the globe about the southern hemisphere's mid-latitudes once every one to three weeks, depending on wind speeds in the stratosphere, Nasa said.
The aim is for it remain airborne for more than 100 days.
The balloon's operational float altitude is 33.5km and will be visible from the ground, particularly at sunrise and sunset, in the southern hemisphere's mid-latitudes, such as Argentina and South Africa.
Nasa's balloon experts at its Columbia Scientific Balloon Facility and Nasa's Wallops Flight Facility in Virginia will control balloon flight operations throughout the mission.
The balloon is expected to fall back to earth in South America.
The current record for a Nasa super pressure balloon flight is 54 days.
Tuesday's launch was the second super pressure balloon mission from Wanaka. The first occurred on March 27 last year, flying 32 days, 5 hours, and 51 minutes.