WATCH LIVE: A United Launch Alliance to Launch Delta IV Heavy Rocket #Pa...

A United Launch Alliance Delta IV Heavy rocket will launch NASA's Parker Solar Probe from Cape Canaveral Air Force Station in Florida at 3:33-4:38 a.m. EDT (0733-0838 GMT)

Liftoff window begins at 2:33 a.m. EST

Parker Solar Probe is humanity’s first mission to the sun. After launch, it will orbit directly through the solar atmosphere – the corona – closer to the surface than any human-made object has ever gone. While facing brutal heat and radiation, the mission will reveal fundamental science behind what drives the solar wind, the constant outpouring of material from the sun that shapes planetary atmospheres and affects space weather near Earth.