Video: NROL-37 payload and Delta 4-Heavy rocket prepped for launch

Launch of an Atlas 5 rocket from Cape Canaveral with a U.S. Air Force infrared surveillance satellite was scrubbed Thursday evening after engineers encountered a balky valve associated with the first stage’s liquid oxygen system.

Riding the rails between its assembly building and the launch pad, an Atlas 5 rocket topped with a clandestine national security satellite was rolled out this morning for Thursday’s liftoff at 4:07 a.m. EDT (0807 GMT).

Under a brilliant moon, a United Launch Alliance Atlas 5 rocket flashed to life and vaulted away from Cape Canaveral late Sunday, boosting the European Space Agency’s $1.5 billion Solar Orbiter probe out of Earth’s gravitational grip toward a multi-year voyage around the sun that will give scientists their first glimpse of the star’s poles.