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

The Atlas 5 rocket that will send NASA’s Perseverance rover toward Mars next month aced a countdown rehearsal Monday at Cape Canaveral, helping ensure the United Launch Alliance-built rocket is ready for liftoff during the rover’s 23-day launch window.

America’s next Mars rover, a $2.1 billion nuclear-powered vehicle to search for evidence that life once existed there, will be launched to the Red Planet in the summer of 2020 by a powerful Atlas 5 rocket.

A United Launch Alliance Atlas 5 rocket fired into the night sky over Cape Canaveral just after midnight Wednesday, carrying the U.S. Air Force’s fourth AEHF communications satellite designed to enable secure voice, video and data links between U.S. and allied forces.