NASA and SpaceX are scheduled to launch astronauts Douglas Hurley and Robert Behnken on a mission to the International Space Station at 3:22 pm Eastern Time.
'Demo -2' launch marks the first flight of NASA crew from the US soil since 2011 and the first launch of a rocket owned by a private company: SpaceX, the commercial space company founded by Elon Musk.
NASA has assigned two of its most experienced astronauts, Behnken and Hurley to the upcoming SpaceX mission.
If successful, this would be a big win for SpaceX's first-ever crewed mission in the company's 18-year history.