Inside Building 836 at Vandenberg Air Force Base in California, one of the payload fairing halves for the United Launch Alliance (ULA) Delta II rocket is being rotated on its metal frame for securing on a work stand. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) is scheduled to launch on the final ULA Delta II rocket later this year. 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 a single instrument, the Advanced Topographic Laser Altimeter System. 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.