Video: Time-lapse of Atlas 5’s rollout for launch of GOES-S (members only)

Weather forecasters expect a 70 percent chance of favorable conditions at Cape Canaveral for liftoff of a United Launch Alliance Delta 4 rocket Thursday with a GPS navigation satellite, marking the last flight of the Delta 4’s single-core variant after 29 flights since 2002.

Launching the secretive NROL-61 payload for the U.S. National Reconnaissance Office, a United Launch Alliance Atlas 5 rocket thundered away from Cape Canaveral today at 8:37 a.m. EDT (1237 GMT).

A United Launch Alliance Delta 4 rocket lifted off from Cape Canaveral on Wednesday night with the U.S. Air Force’s eighth Wideband Global SATCOM communications satellite, lighting up the sky in these images taken from the nearby Kennedy Space Center press site.