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

Russian officials have delayed until Saturday the launch of a Proton rocket from Kazakhstan with the Spektr-RG X-ray astronomy observatory, an ambitious mission jointly developed with Germany to probe dark energy.

Russia’s new Angara 5 rocket, the biggest Russian launcher since the end of the Cold War, made a pre-dawn blastoff from the wintry Plesetsk Cosmodrome on Tuesday on a successful first flight. See video and photos of the fiery liftoff from the snowy launch pad.

SpaceX performed a hold-down test-firing Jan. 20 of a Falcon 9 rocket at Cape Canaveral in preparation for a launch with 60 Starlink broadband satellites, but officials delayed the missions’s planned launch Tuesday due to extreme weather in the downrange recovery zone for the first stage and payload fairing. The next possible launch attempt is expected at 9:49 a.m. EST (1449 GMT) Monday.