Photos: Atlas 5 rocket aims for International Space Station

SpaceX is gearing up for the first commercial launch of its powerful Falcon Heavy rocket as soon as early April with a communications satellite for Arabsat, and the U.S. Air Force hopes the two side boosters from the Arabsat mission can be safely landed and reused for the military’s first Falcon Heavy mission this summer, an exercise officials said will help certify previously-flown hardware for future national security launches.

Flying for the first time this year, a Proton rocket streaked into space Thursday from the Baikonur Cosmodrome in Kazakhstan with two Russian Express communications satellites that will beam television, radio and broadband signals across the country.

A $1.1 billion science investigation involving four formation-flying satellites circling the Earth will share a single Atlas 5 rocket launch Thursday night from Cape Canaveral to probe explosions in the magnetic field with millisecond speed.