NASA super pressure balloon set to launch from Wanaka in early May

NASA is set to soar above Wanaka for the first time in five years with the return of the US space agency's Scientific Balloon Program to the South Island.

The flight is another test of the super pressure balloon (SPB) technology designed to support long duration science missions with flights of up to 100 days.

This will be the fourth test launch from Wanaka Airport since NASA first set flight in 2015, but the first since 2017. It is NASA's dedicated launch site for mid-latitude, long-duration balloon missions.

A proposed launch in 2020, which saw the team travel to Aotearoa to begin preparations, was cancelled due to the COVID-19 pandemic.

"We are on the cusp of perfecting our SPB balloon technology, which is poised to expand opportunities for all sorts of science and technology missions by providing relatively low-cost, near-space access for long-duration flight times at mid-latitudes," said Debbie Fairbrother, chief of NASA's Balloon Program Office.

"For certain types of science, we can achieve the same results on a balloon that could only otherwise be achieved by flying into space on a rocket. Certifying the balloon as a long-duration flight vehicle is key to supporting bigger and more complex science missions in the future."

The SPB is a massive 532,000-cubic-metre, pressurised vehicle designed to float at a constant altitude despite the heating and cooling of the day-night cycle.

When fully inflated with helium and at its operational altitude of 33.5km, the balloon is about the same size as the Forsyth Barr Stadium in Dunedin.

Past SPB flights have led to new processes and procedures for constructing the upper and lower fittings of the balloon to ensure the balloon stays pressurised during the expansion and contraction caused by temperature changes, NASA said.

The science and engineering communities have also identified long-duration balloon flights as playing an important role in providing inexpensive access to the near-space environment for science and technology.

The team in Wanaka is targeting early May for the balloon's launch.

After this year's flight, the team plans to return to Wanaka in 2023 for two super pressure balloon flights, each with its own dedicated science mission of opportunity, NASA said.