Photos: Atlas 5 rocket aims for International Space Station

A commercial Dragon cargo capsule wrapped up a four-week stay at the International Space Station on Monday with a departure from the complex at 12:01 p.m. EDT (1601 GMT). The spacecraft splashed down in the Pacific Ocean at 5:48 p.m. EDT (2148 GMT) with several tons of research specimens and equipment.

SpaceX’s second Falcon Heavy rocket is set for liftoff Thursday from NASA’s Kennedy Space Center in Florida, and the heavy-lift launcher will head on an easterly course over the Atlantic Ocean atop more than 5 million pounds of thrust.

A United Launch Alliance Delta 4 rocket went through a practice countdown and fueling exercise this week to prepare for its Aug. 19 liftoff to deliver a pair of orbital surveillance satellites into space.