Live coverage: Ariane 5 rocket soars with Sky Muster, Arsat 2

Ground crews at the Guiana Space Center in South America have spent the last few months preparing the BepiColombo spacecraft, a tandem mission with European and Japanese science orbiters bound for Mercury, for launch aboard an Ariane 5 rocket.

Four satellites designed to broadcast high-speed Internet signals to the developing world are mounted on top of a Russian-made Soyuz rocket for liftoff Thursday from the Guiana Space Center in South America. See photos of the quartet of satellites undergoing launch preparations.

The Canadian telecom satellite operator Telesat plans to launch two multipurpose communications spacecraft aboard SpaceX Falcon rockets in 2018, the company disclosed this week in a quarterly earnings announcement.