US President Donald Trump plans to be on the Florida coast on Wednesday to watch American astronauts blast into orbit from the Kennedy Space Centre for the first time in more than a decade.
It will be the first time since the space shuttle programme ended in 2011 that US astronauts will launch into space aboard an American rocket from American soil.
Also new on Wednesday: a private company – not Nasa – will be running the show.
Elon Musk’s SpaceX is the conductor and Nasa the customer as businesses begin chauffeuring astronauts to the International Space Station.
The Nasa/SpaceX Commercial Crew flight test launch will carry Nasa’s newest test pilots, Doug Hurley and Bob Behnken, in a SpaceX Crew Dragon capsule on a SpaceX Falcon 9 rocket.
They are scheduled to blast off from launch pad 39A, the same one the Apollo astronauts used to get to the moon.
The shift to private companies allows Nasa to zero-in on deep space travel. The space agency is working to return astronauts to the moon by 2024 under orders from the White House, but that deadline appears increasingly unlikely even as three newly chosen commercial teams rush to develop lunar landers. Mars also beckons.
The White House portrayed the launch as an extension of Mr Trump’s promise to reassert American dominance in space. He recently oversaw the creation of the Space Force as the sixth branch of the armed forces.
“Our destiny, beyond the Earth, is not only a matter of national identity, but a matter of national security,” Mr Trump said in a statement.
Vice president Mike Pence, who is chairman of the National Space Council, also plans to attend the launch.