It was a rainy day at the Esrange Space Center in Kiruna, Sweden, on Aug. 6, 2015. Instead of being able to perform the final comprehensive tests on BARREL’s six payloads, the team had to keep all their equipment indoors. This image is of the first flight train hang test as BARREL team members — including Robyn Millan, the principal investigator from Dartmouth College in Hanover, New Hampshire — look on.
The NASA-funded BARREL – which stands for Balloon Array for Radiation-belt Relativistic Electron Losses – measures electrons in the atmosphere near the poles and is a component of NASA’s Van Allen Probes. Such electrons rain down into the atmosphere from two giant radiation belts surrounding Earth, called the Van Allen belts. BARREL’s third campaign includes launching six balloons from the Esrange Space Center. BARREL is led by Dartmouth College. Credit: NASA/Dartmouth/Kathryn Waychoff