NASA super pressure balloon begins around-the-world journey

NASA has successfully launched a super pressure balloon on a potentially record-breaking, around-the-world test flight aimed at providing inexpensive access to the near-space environment for science and technology research.
The purpose of the flight is to test and validate the super pressure balloon (SPB) technology with the goal of long-duration flight (over 100 days) at mid-latitudes.
The balloon, launched from Wanaka Airport in New Zealand, is carrying the Compton Spectrometer and Imager (COSI) gamma-ray telescope as a mission of opportunity.
"The balloon is pressurised, healthy, and well on its way for this important test mission," said Debbie Fairbrother, NASA's Balloon Programme Office chief.

Two hours and 8 minutes after lift-off, the 532,000 cubic metre balloon reached its operational float altitude of 33.5 kilometres flying a trajectory taking it initially westward through southern Australia before entering into the eastward flowing winter stratospheric cyclone.
NASA estimates the balloon will circumnavigate the globe about the southern hemisphere's mid-latitudes once every one to three weeks, depending on wind speeds in the stratosphere.

This launch marks the beginning of the second SPB flight for COSI, which was developed by the University of California, Berkeley.
COSI is a 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. Long-duration flights are vital to these types of studies.

Another mission of opportunity is the Carolina Infrasound instrument, a small, 3-kilogramme payload with infrasound microphones designed to record acoustic wave field activity in the stratosphere.
Developed by the University of North Carolina at Chapel Hill, previous balloon flights of the instrument have recorded low-frequency sounds in the stratosphere, some of which are believed to be new to science.
It was the fifth launch attempt for the team; previous attempts were scrubbed due to weather conditions not conducive for launch.
The current record for a NASA super pressure balloon flight is 54 days.
As the balloon travels around the Earth, it may be visible from the ground, particularly at sunrise and sunset, to those who live in the southern hemisphere's mid-latitudes, such as Argentina and South Africa.