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.

The first of up to seven United Launch Alliance missions lifted off Jan. 19 from Vandenberg Air Force Base in California, where a Delta 4-Heavy launcher fired into orbit with 2.1 million pounds of thrust from three hydrogen-fueled RS-68A main engines with a U.S. government spy satellite.

A United Launch Alliance Atlas 5 rocket departs Vandenberg Air Force Base today at 10:30 a.m. local time (1:30 p.m. EST; 1830 GMT) to deliver the commercial WorldView 4 Earth-imaging satellite into polar orbit for DigitalGlobe.