With the on-time liftoff by the 260-foot rocket, SpaceX, founded by Musk, the Tesla electric-car visionary, became the first private company to launch people into orbit, a feat achieved previously by only three governments: the U.S., Russian Federation and China.
NASA-SpaceX Demo-2 successful separation of the second Falcon 9 stage.
The Crew Dragon capsule is bound for the International Space Station, 402 kilometers (250 miles) above Earth.
Since then, NASA astronauts have had to hitch rides into orbit aboard Russia's Soyuz spacecraft.
Behnken, 49, and Hurley, 53, former military test pilots who joined the U.S. space agency in 2000, are to blast off from Launch Pad 39A.
The US space agency had given SpaceX and Boeing, which plans its first manned space flight next year, nearly $8 billion to develop the new American-made rockets.
"This is a great time in America to be able to do this again", Hurley said in comments May 20 when he and Behnken arrived at KSC for the launch, calling the development of commercial crew vehicles a "marathon" by NASA and SpaceX.
Behnken and Hurley were going through the same preparations Saturday that they went through on Wednesday.
Musk's success means that NASA won't have to concern itself with mundane lower space orbit travel and can focus on "gearing up for another trip to the moon and beyond", McDowell said.
Trump tweets are now labelled as "potentially misleading"
Trump reiterated his accusations of political bias by such technology platforms, tweeting: "Republicans feel that Social Media Platforms totally silence conservatives voices ".
Eastern Time, from historic Launch Complex 39A at the Kennedy Space Center.
Four minutes into launch, NASA declared that the mission had achieved main engine cutoff (MECO) and separation from the first stage.
Image Source: ERIK S LESSER/EPA-EFE/ShutterstockSpaceX founder Elon Musk jumps in the air inside the the Vehicle Assembly Building after the manned SpaceX Falcon 9 Crew Dragon Demo-2 mission lifted off from the Kennedy Space Center, Florida. "It's been nine years since we've launched American astronauts on American rockets from American soil, and now it's done".
Under its Commercial Crew Program that started 10 years ago, NASA has worked with the private sector to develop a successor to the shuttle program, awarding SpaceX and Boeing Co. contracts worth $3.1 billion and $4.8 billion, respectively.
Boeing is producing a launch system in competition with SpaceX. "One of the reasons I wanted to be here today, and I think any one of you would say, that was an inspiration to see right now".
The hatch on Crew Dragon is to be closed about two hours before blastoff, followed by the arming of the emergency escape system.
A SpaceX capsule exploded on the test stand a year ago.
Through live coverage provided by NASA, the two veteran American astronauts - Douglas Hurley, 53, and Robert Behnken, 49 - were seen ahead of liftoff wearing sleek white space suits while buckled up in front of touchscreen control panels inside the Crew Dragon capsule. "[He's] brought vision and inspiration", he said Friday at a NASA news conference.
SpaceX has been launching cargo capsules to the space station since 2012.