Live coverage: SpaceX launches its fifth Falcon 9 flight of the year

The Falcon Heavy engine test firing at launch pad 39A seen in 4K high resolution video. The engines fired at 12:30pm EST (1730 GMT) on 24 January 2018 as part of a crucial pre-launch test.

For the second day running, computers automatically aborted a Falcon 9 launch countdown Monday at NASA’s Kennedy Space Center in Florida in the final seconds before liftoff with the Intelsat 35e communications satellite.

SpaceX chief executive Elon Musk will unveil his plans for human missions to Mars on Tuesday in a presentation at the International Astronautical Congress in Guadalajara, Mexico. Watch the speech live at 2:30 p.m. EDT (1830 GMT).