Live coverage: 400th Proton rocket takes off with Russian satellite

A pioneering Northrop Grumman-built satellite designed to dock with an aging spacecraft more than 22,000 miles above Earth, then extend its life with the aid of solar-electric thrusters, is set for launch Wednesday from Kazakhstan aboard a Proton rocket.

Russia launched a military communications satellite Wednesday, sending a data relay and broadcasting station to an orbit more than 22,000 miles above the equator aboard a Proton rocket and a Breeze M upper stage.

Poised to loft a Russian-German X-ray astronomy observatory into space Friday, a Proton rocket returned to its launch pad Tuesday at the Baikonur Cosmodrome in Kazakhstan after a three-week delay to replace a drained battery on the vehicle.