Update 4:20 p.m. ET: SpaceX has rescheduled the launch for Friday due to high winds today.
On Tuesday at 6:35 p.m. EST, Elon Musk's rocket company SpaceX will attempt for the fourth time in a week to launch its Falcon 9 rocket from Cape Canaveral, Florida, in order to deliver a commercial satellite into orbit. The mission has been thwarted in recent days due to poor weather and a ship that floated too close to the launch site.
About 10 minutes after liftoff, SpaceX hopes to land the rocket upright on a robotic barge off the coast of Florida. Previous ocean landing attempts have seen varying degrees of success, and a few explosions.
Read more about tonight's mission here, and watch the live stream below starting around 6:20 p.m. ET.