SpaceX conducts engine test fire for communications satellite launch (members only)

The United Launch Alliance Delta 4 rocket, standing 217 feet tall and weighing 900,000 pounds, unleashes 1.8 million pounds of thrust from its main engine and four side-mounted boosters at 8:18 p.m. EDT Saturday (0018 GMT Sunday) to launch the ninth Wideband Global SATCOM satellite for U.S. military and allied communications.

Amazon has selected United Launch Alliance’s Atlas 5 rocket for nine missions from Cape Canaveral to deploy satellites for the Kuiper internet constellation, a fleet designed to eventually number more than 3,200 spacecraft, the companies announced Monday.

The touchdown of booster 1075 marked SpaceX’s 450th Falcon booster landing. Liftoff from pad 4 East happened at 3:32 p.m. PDT (6:32 p.m. EDT, 2232 UTC).