Live coverage: Two satellites lift off aboard Ariane 5

Extra testing of the James Webb Space Telescope and delays in assembling the powerful observatory will push back the $10 billion mission’s launch by at least six months to early 2019, officials announced last week as the telescope successfully completed an extensive performance test inside a cryogenic vacuum chamber in Houston.

SpaceX’s Falcon 9 rocket disintegrated shortly after launch from Cape Canaveral on Sunday, dealing a blow to the entrepreneurial space company and NASA’s supply chain to the International Space Station.

The first Ariane 5 rocket scheduled for launch in 2018 has been topped off with two communications satellites for SES and Yahsat, moving the European booster closer to liftoff Thursday from a tropical launch pad in French Guiana with payloads to serve commercial and scientific missions.