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

A previously-flown SpaceX Falcon 9 rocket booster conducted a test-firing Monday at NASA’s Kennedy Space Center in Florida, ahead of a planned launch Oct. 7 with an Airbus-built communications satellite made for SES and EchoStar.

The Russian government is investigating flaws found in Proton rocket engines, ordering all suspect components to be replaced before the heavy-lift booster can resume launches and promising penalties for those responsible for allowing substandard parts to slip through inspection.

The launch of a United Launch Alliance Delta 4-Heavy rocket from Cape Canaveral was aborted three seconds before a planned liftoff at 3:28 a.m. EDT (0728 GMT). The rocket was set to loft a classified payload for the National Reconnaissance Office, the U.S. government’s spy satellite agency.