The SpaceX Falcon 9 rocket carrying the Dragon spacecraft lifts off from Launch Complex 39A at NASA’s Kennedy Space Center in Florida on Monday, April 21, on the company’s 32nd commercial resupply services mission for the agency to the International Space Station. Liftoff was at 4:15 a.m. EDT. Dragon will deliver a variety of science experiments, including a demonstration of refined maneuvers for free-floating robots. Dragon also carries an enhanced air quality monitoring system that could protect crew members on exploration missions to the Moon and Mars, and two atomic clocks to examine fundamental physics concepts such as relativity and test worldwide synchronization of precision timepieces.