Weather looks good for SpaceX launch Friday"

The forecast looks favorable for a 4:43 p.m. ET Friday launch of a SpaceX Falcon 9 rocket and Dragon cargo capsule bound for the International Space Station.

Meteorologists at the Air Force's 45th Weather Squadron anticipate a 90% chance of acceptable conditions during the instantaneous window at Cape Canaveral Air Force Station's Launch Complex 40.

The primary weather concern for launch is liftoff winds, the forecast reads.

SpaceX late Tuesday completed a practice countdown that culminated with a brief test-firing of the rocket's nine Merlin main engines, a standard pre-launch milestone, and said engineers were reviewing the data.

The company is launching its first Dragon spacecraft since last June, when its Falcon 9 rocket failed about two minutes after liftoff. No Dragon has visited the ISS since last April.

The launch will be SpaceX's fourth since December and third of an upgraded Falcon 9 rocket providing more thrust at liftoff.

Among the cargo the Dragon is delivering to the station is a prototype expandable module designed by Bigelow Aerospace, which over two years will test technology that could underpin a future space station or deep space habitat.

After the launch, SpaceX plans to try an experimental landing of the Falcon 9 rocket's first stage on a "drone ship" stationed down range in the Atlantic Ocean, a feat it has not yet achieved.

If there is no launch Friday, SpaceX will try again Saturday.

04:47