A second super pressure balloon has been launched from Wānaka Airport by NASA.
It comes just under a month after the first balloon was launched, and is planned to spend 100 days or more, flying in the Earth's upper atmosphere.
In a statement, NASA scientific balloon program chief Debbie Fairbrother said having two super pressure balloons in flight at the same time was a goal 15 years in the making.
"I'm so thrilled that on this day, we did it.
"I could not be prouder of our balloon and science teams for their accomplishment. With these two flights, we are setting ourselves up to support more and more advanced science in the coming years."
NASA said the Extreme Universe Space Observatory 2 (EUSO-2) was flying on the newly-launched balloon.
It was a science mission from the University of Chicago and aimed to build on data collected during a different mission in 2017.
"EUSO-2 will detect ultra-high energy cosmic-ray particles from beyond our galaxy as they penetrate Earth's atmosphere. The origins of these particles are not well known, so the data collected from EUSO-2 will help solve this science mystery," NASA said.
"Along with EUSO-2 being a science mission of opportunity, the overall goal of the mission is to test and qualify the super pressure balloon technology for flight."
NASA said the first balloon, which was launched in April, was performing as it should and was flying at about 108,000 feet.