The second stage of the United Launch Alliance Delta II rocket is lifted high up at the Vertical Integration Facility, at left, at Space Launch Complex 2 on June 21, 2018, at Vandenberg Air Force Base in California. The second stage will be attached to the top of the booster, or first stage of the rocket, which is being moved out of the Mobile Service Tower, at right. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch 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.

United Launch Alliance workers prepare the first stage of the Delta II second stage to be lifted up in the Vertical Processing Facility at Space Launch Complex 2 on June 21, 2018, at Vandenberg Air Force Base in California. The second stage will be attached to the top of the booster, or first stage, of the rocket. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch 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.

The United Launch Alliance Delta II second stage is lifted high up at the Vertical Integration Facility at Space Launch Complex 2 on June 12, 2018, at Vandenberg Air Force Base in California. The second stage will be attached to the top of the booster, or first stage of the rocket. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch 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.

The United Launch Alliance Delta II booster, or first stage, with the interstage attached on top is moved out of the Vertical Integration Facility (VIF) at Space Launch Complex 2 on June 21, 2018, at Vandenberg Air Force Base in California. The second stage will be lifted up at the VIF. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch 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.

United Launch Alliance workers prepare the first stage of the Delta II second stage to be lifted up in the Vertical Processing Facility at Space Launch Complex 2 on June 21, 2018, at Vandenberg Air Force Base in California. The second stage will be attached to the top of the booster, or first stage, of the rocket. NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) will launch 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.