Watch the Falcon 9 launch from pad 39A

SpaceX called off a scheduled launch of a Falcon 9 rocket about a half-hour before liftoff from Cape Canaveral Monday due to strong upper level winds, and officials aim to try again to send 60 Starlink Internet satellites into orbit Wednesday after bypassing a planned launch attempt Tuesday due to poor weather in the offshore booster recovery area.

SpaceX launched a Falcon 9 rocket Sunday from Cape Canaveral with 143 small satellites, a record number of spacecraft on a single mission, giving a boost to startup space companies and stressing the U.S. military’s tracking network charged with sorting out the locations of all objects in orbit.

Two space station astronauts are gearing up for a planned six-and-a-half-hour spacewalk Friday to replace a presumably shorted out solar array voltage regulator that knocked one of the lab’s eight power channels out of action late last year.