Live coverage: Cygnus supply ship departs space station

A European Ariane 5 rocket delivered two commercial communications satellites to orbit Thursday after Arianespace’s ground team lost telemetry from the launcher during its climb into orbit, raising concerns that the mission might have failed. The SES 14 and Al Yah 3 satellites are confirmed in orbit and healthy, but the parameters of their orbits are unknown. Both were heading toward 22,000-mile-high geostationary perches over the equator.

Investigators believe a leak of propellant inside the Crew Dragon spacecraft’s propulsion system led to the capsule’s explosion April 20 during a ground test at Cape Canaveral, and a senior SpaceX official said Monday that delays are making it “increasingly difficult” to fly astronauts on the commercial spaceship before the end of the year.

SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral on Monday, heading due east over the Atlantic Ocean to deliver the JCSAT 18/Kacific 1 communications satellite into orbit around 33 minutes later.