Video: Zoomed in view of ignition of Falcon 9 engines in prelaunch test (members only)

SpaceX fueled its next Falcon 9 rocket at launch pad 39A and ignited the booster’s nine Merlin engines at sunset Thursday, passing a major step in the launch campaign leading up to liftoff of the Intelsat 35e communications satellite Sunday.

The 32-story-tall mobile service tower at the Delta 4’s launch pad at Vandenberg Air Force Base in California was retracted away from the rocket Thursday in advance of a planned liftoff with a top secret National Reconnaissance Office payload.

Equipped with a robot arm, sample collector and return capsule, NASA’s asteroid-bound OSIRIS-REx probe emerged from its pristine factory and flew to the launch site in Florida on Friday.