PUBLISHED: 18:10, Sat, May 30, 2020 | UPDATED: 18:23, Sat, May 30, 2020
NASA and SpaceX were forced to delay the Crew Dragon launch earlier this week due to a tropical storm near the coast of South Carolina. NASA administrator Jim Bridenstine has now given the green light for Crew Dragon to launch once again with a 50 percent chance of another delay. If the launch goes ahead, it will mark the first flight of NASA astronauts from US soil in nine years.
NASA astronauts Bob Behnken and Doug Hurley were selected to lead the mission, dubbed Demo-2, as they blast off towards the International Space Station (ISS).
The astronauts arrived at the Kennedy Space Center's iconic Launch Complex 39A just after 5pm BST.
The same launchpad saw Apollo fly to the Moon and back as well as 82 launches of the Space Shuttle.
NASA said: "After the Space Shuttle was retired in 2011, NASA began the process to transform Kennedy Space Center from a historically government-only launch facility into a multi-user spaceport for both government and commercial use.
READ MORE: SpaceX launch at risk as bad weather threatens Demo-2
NASA launch time UK: The Crew Dragon will attempt to launch a second time today (Image: NASA/SPACEX)
NASA launch time: Astronauts Doug Hurley (left) and Bob Behnken (right) (Image: NASA TV)
"On April 14, 2014, the agency signed a property agreement with SpaceX of Hawthorne, California, for use of the launch site for the next 20 years.
"SpaceX upgraded and modified the launch pad to support its Falcon 9 and Falcon Heavy rockets."
Should bad weather get in the way of a safe launch, a second backup window will open on Sunday.
NASA said: "The countdown continues to go well for today's planned 3.22pm EDT launch of NASA's SpaceX Demo-2 flight test to the International Space Station."
The countdown continues to go well for today's planned 3.22pm EDT launch