At Vandenberg Air Force Base in California, NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) is inside the mobile service tower at Space Launch Complex 2, on Aug. 26, 2018. The satellite will be attached to the top of the United Launch Alliance Delta II rocket. Launch is scheduled for Sept. 15, 2018. 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 the Advanced Topographic Laser Altimeter System (ATLAS). ICESat-2 will help scientists investigate why, and how much our planet's frozen and icy areas, called the cryosphere, are changing in a warming climate.