Videos: Replays from successful Atlas 5 launch of TDRS-M

A towering mobile platform for the agency’s Space Launch System arrived at launch pad 39B Friday at the Kennedy Space Center in Florida for a sequence of water and propellant flow tests, swing arm checkouts and other rehearsals that should conclude with managers declaring the spaceport’s ground systems ready to support the first SLS launch campaign by the end of the year.

SpaceX conducted a final Launch Readiness Review on Monday ahead of the scheduled liftoff Wednesday of NASA astronauts Doug Hurley and Bob Behnken on a test flight of the Crew Dragon spacecraft to the International Space Station. Launch remains set for 4:33:33 p.m. EDT (2033:33 GMT) Wednesday, weather permitting.

With Tropical Depression Eta forecast to restrengthen into a tropical storm and move toward Florida, United Launch Alliance moved an Atlas 5 rocket off its launch pad at Cape Canaveral Friday and delayed liftoff with a U.S. government spy satellite to Wednesday.