The third U.S. National Climate Assessment was released which took observations from NASA's fleet of satellites to help understand climate change in the United States. Also, NASA's Orbiting Carbon Observatory-2 spacecraft arrived at California's Vandenberg Air Force Base to begin final preparations for a scheduled July 1 launch. In Florida, the remaining flight hardware for the Delta IV rocket that will launch NASA's Orion spacecraft on Exploration Flight Test-1 in December arrived at Port Canaveral. At the Stennis Space Center, a cold-shock test for the RS-25 engine that will help power NASA's new Space Launch System rocket was completed.