Live coverage: Proton blasts off on return-to-flight mission

SpaceX and NASA launched a planet-hunting satellite Wednesday from Cape Canaveral, two days after calling off a launch attempt to conduct additional guidance, navigation and control analyses. Liftoff occurred at 6:51 p.m. EDT (2251 GMT), and the first stage of the Falcon 9 rocket successfully landed on a drone ship in the Atlantic Ocean.

SpaceX aims to re-launch the Falcon 9 booster Monday that catapulted astronauts Doug Hurley and Bob Behnken toward the International Space Station in May, this time carrying a South Korean military communications satellite while pursuing a record for the quickest turnaround time between flights of an orbital-class rocket stage.

SpaceX test-fired its next Falcon 9 rocket Friday ahead of a planned launch Monday from Cape Canaveral with 60 more Starlink Internet satellites, days after an international group sounded another warning about the effects of large satellite fleets on astronomy.