In 2013, balloons were launched by NASA near the North and South poles to study X-rays in Earth’s atmosphere

In 2013, balloons were launched by NASA near the North and South poles to study X-rays in Earth’s atmosphere as part of the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission. The mission studied electrons falling from the Van Allen Belts, measured X-rays and electron precipitation, and supported spacecraft observations to understand radiation around Earth.