Elon Musk's private rocket company SpaceX was set for a repeat attempt at launching two Americans into orbit on Saturday from Florida for a mission that would mark the first spaceflight of NASA astronauts from USA soil in nine years.
As NASA reports, both the Falcon 9 rocket and Crew Dragon spacecraft "remain in good shape and stand ready for launch at the pad".
In the years since NASA ended its own Space Shuttle Program, NASA astronauts have had to resign themselves to traveling to Russian Federation to train on its Soyuz spacecraft.
Behnken, 49, and Hurley, 53, former military test pilots who joined the USA space agency in 2000, are to blast off from Launch Pad 39A.
SpaceX CEO Elon Musk was asked when his company's Starship super-rocket, which is now under development, could be expected to make its first flight around the moon. Saturday's weather cooperated, allowing a successful launch at 3:22 p.m. EDT (1922 GMT).
You can actually try out the manual control system that Behnken and Hurley used yourself - no spaceship required.
Asked why he felt it was important to be in Florida for the launch, given all that is going on in the country, Mr Trump said the launch was a "great inspiration" for the country.
Approximately 150,000 people also went to witness the historic launch on Wednesday, despite NASA's warnings to stay home to prevent the spread of the new coronavirus. The Crew Dragon spacecraft atop the rocket's upper stage separated 12 minutes later after achieving low Earth orbit. The success of NASA's Demo-2 brings the USA closer to eventually bringing astronauts back to the Moon, and then possibly on to Mars.
"For the first time in nine years, we have now launched American astronauts on American rockets from American soil". Trump said he plans to return for Saturday's retry. "I'm so proud of the NASA and SpaceX team for making this moment possible". In 2014, Boeing and SpaceX won Commercial Crew Transportation Capability (CCtCap) contracts to complete development and testing of their commercial crew vehicles and for initial flights to the ISS.
If Crew Dragon proves safe, it may ferry more than astronauts.
Waves and wind needed to be within limits in case the SpaceX Dragon crew capsule had to make an emergency splashdown on the way to orbit. The company has built and tested the capsule for the past six years.
NASA astronauts Doug Hurley, left, and Bob Behnken shake hands outside the Neil A. Armstrong Operations and Checkout Building at the Kennedy Space Center in Cape Canaveral on Wednesday.
"It's something we maybe dreamed about when we were new [astronaut candidates] - flying something other than the space shuttle", Behnken said. "I think it's kind of a culmination".