KSC-07pd0977

KENNEDY SPACE CENTER, FLA. -- On a runway at Vandenberg Air Force Base in California, the Orbital Sciences Stargazer L-1011 aircraft takes off at 4:26 p.m. EDT with its underbelly cargo of the Pegasus XL rocket-AIM spacecraft. The aircraft will release the Pegasus XL rocket at a drop point over the Pacific Ocean, 100 miles offshore west-southwest of Point Sur, Calif. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25. Photo credit: NASA/Tim Gordon