NASA's balloon is still flying high today, nearing Australia's west coast after a successful launch at Wanaka Airport yesterday morning.
The super pressure balloon (SPB) had lift off at 11:35am on what NASA is calling a "potentially record-breaking, around-the-world test flight".
It was fifth time lucky for the team after windy conditions hampered previous efforts. The balloon needed four knots or less to launch.
Two hours and eight minutes after lift-off, the 532,000-cubic-metre balloon reached its operational float altitude of 33.5 kilometres.
The team laying out the balloon yesterday in perfect weather conditions (NASA)
The purpose of the flight is to test and validate the SPB technology with the goal of long-duration flight at mid-latitudes. NASA is hoping the balloon will stay sky high for at least 100 days.
It's also carrying the Compton Spectrometer and Imager (COSI) gamma-ray telescope. COSI is a NASA-funded mission designed to probe the "mysterious origins of galactic positrons, study the creation of new elements in the galaxy, and perform pioneering studies of gamma-ray bursts and black holes".
As the balloon travels around the Earth, it may be visible from the ground to those who live in the southern hemisphere's mid-latitudes, such as Argentina and South Africa.
You can track the balloon here.