Video: Atlas 5 rolls out to launch pad with the Air Force’s AEHF 5 comsat (members only)

NASA has selected a SpaceX Falcon 9 rocket — flying with a reused first stage booster — to launch the Imaging X-ray Polarimetry Explorer mission from pad 39A at the Kennedy Space Center in Florida in April 2021, bypassing Northrop Grumman’s air-launched Pegasus rocket for the task.

The United Launch Alliance Delta 4-Heavy rocket, standing 235 feet tall and weighing 1.6 million pounds fully fueled, unleashes 2.1 million pounds of thrust from the three RS-68A main engines at 1:51 p.m. EDT (1751 GMT) today to launch from Cape Canaveral on NROL-37.

There’s a new launch being added to Vandenberg Air Force Base’s schedules — another Delta 4 rocket flight for the National Reconnaissance Office.