Delta II ICESat-2 Atlas Instrument Flight Door Opening

Inside the high bay of the Astrotech Space Operations facility at Vandenberg Air Force Base in California, a technician opens and checks the flight door for the Advanced Topographic Laser Altimeter System (ATLAS) on NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) on June 21, 2018. The satellite is being prepared for its scheduled launch from Space Launch Complex-2 at Vandenberg on the final United Launch Alliance Delta II rocket. ICESat-2 will measure the height of a changing Earth, one laser pulse at a time, 10,000 laser pulses a second. The satellite will carry ATLAS. ICESat-2 will help scientists investigate why, and how much our planet's frozen and icy areas, called the cryosphere, is changing in a warming climate.