Live coverage: Proton soars into space with Inmarsat satellite

The countdown for a planned launch of a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida automatically aborted in the last second before liftoff Sunday after an on-board computer detected unexpected data during an engine power check.

A 180-foot-tall Ariane 5 rocket climbed into space from French Guiana on Thursday evening, but the mission ran into problems a few minutes later.

Lockheed Martin will build two communications satellites for Saudi Arabia’s Arabsat, and Arianespace and SpaceX will launch the commercial relay platforms under contracts valued at $650 million announced Wednesday.