Inside NASA's Building 1555 at Vandenberg Air Force Base in California, the United Launch Alliance Delta II second stage is secured on the base of a transporter. The second stage will be moved to the horizontal processing facility at Space Launch Complex-2. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch later this year on the final 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 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