A SpaceX Falcon Heavy rocket carrying 24 satellites as part of the Department of Defense's Space Test Program-2 (STP-2) mission is seen at Launch Complex 39A, Monday, June 24, 2019 at NASA's Kennedy Space Center in Florida. Four NASA technology and science payloads which will study non-toxic spacecraft fuel, deep space navigation, "bubbles" in the electrically-charged layers of Earth's upper atmosphere, and radiation protection for satellites are among the two dozen satellites that will be launched. The three hour launch window opens at 11:30pm EDT on June 24. Photo Credit: (NASA/Joel Kowsky)