Watch a replay of the launch of a Japanese navigation satellite

European engineers test-fired the world’s most powerful present-day single-segment solid rocket booster Monday in French Guiana, clearing a major development hurdle for the Vega-C and Ariane 6 launchers set for debuts in 2019 and 2020.

The first official launch weather outlook issued Tuesday by U.S. Air Force meteorologists predicts an 80 percent chance of favorable conditions for the predawn liftoff Saturday of SpaceX’s Crew Dragon spacecraft on a test flight to the International Space Station.

SpaceX teams working at Vandenberg Air Force Base in California were finalizing preparations Tuesday ahead of the launch of a Falcon 9 rocket Wednesday carrying a trio of Canadian-built radar observation satellites into orbit.