A NASA Super Pressure Balloon with the COSI payload is ready for launch from McMurdo, Antarctica.
A NASA Super Pressure Balloon with the COSI payload is ready for launch from McMurdo, Antarctica. The COSI, which stands for Compton Spectrometer and Imager, payload was flown on the developmental Super Pressure Balloon (SPB). Flight controllers terminated the COSI flight 43 hours into the mission after detecting a small gas leak in the balloon. Credit: NASA