After a brief tornado warning in Brevard County and lightning, SpaceX called off the attempt to launch its Crew Dragon spacecraft carrying NASA astronauts Doug Hurley and Bob Behnken about 17 minutes before the 4:33 p.m. liftoff.
President Donald Trump and Vice President Mike Pence tweeted they will be back on Saturday.
SpaceX has two more opportunities this week to try again. On Saturday, at 3:22 p.m. and again on Sunday at 3 p.m.
The 45th Weather Squadron is predicting a 60% chance of favorable launch weather Saturday.