Live coverage: Atlas 5 countdown and launch journal

The SpaceX Falcon 9 rocket slated to launch two NASA astronauts into orbit May 27 test-fired its nine Merlin booster engines Friday, May 22, on launch pad 39A at the Kennedy Space Center in Florida.

The first Ariane 5 rocket scheduled for launch in 2018 has been topped off with two communications satellites for SES and Yahsat, moving the European booster closer to liftoff Thursday from a tropical launch pad in French Guiana with payloads to serve commercial and scientific missions.

This photo gallery shows the classified National Reconnaissance Office payload, already encapsulated in the 18-foot-diameter nose cone, being lifted atop the United Launch Alliance Atlas-Centaur rocket at Vandenberg Air Force Base’s Space Launch Complex 3-East pad. This milestone was achieved on Aug. 27.