Launch of the United Launch Alliance Atlas V proceeded smoothly without any major issues.

Launch of the United Launch Alliance Atlas V occurred on time under a cloudless, pale blue sky. The countdown proceeded smoothly without any major issues. Five and a half-miles away at the Kennedy Space Center Apollo/Saturn V Center, a group of about 50 Planetary Society staff members and invited guests were on hand to send the spacecraft on its way.
OTV-4 denotes the fourth flight of the U.S. Air Force’s Orbital Test Vehicle, otherwise known as the Boeing X-37B spaceplane. Powered by a single RD-180 engine without the aid of solid rocket boosters, the Atlas V 501 rose slowly into the sky, taking several seconds to clear the lightning towers surrounding the pad. Boeing fact sheets list the vehicle’s weight at five metric tons, roughly 1,000 times heavier than LightSail.