Between today and March 8, SpaceX will aim to prove the safety and reliability of the Crew Dragon before astronauts can take the helm in June this year. The capsule - which was developed to send astronauts to the International Space Station - is a major milestone for Elon Musk's spaceflight company, and a big step in reestablishing NASA's on-hold human spaceflight programme.
SpaceX's first crewed mission, which will fly NASA astronauts Doug Hurley and Bob Behnken, could happen by July, according to NASA's most recent schedule.
Since the Space Shuttle was retired in 2011, NASA has been unable to fly people to space and has been forced to rely on Russian Federation to ferry its astronauts to the space station, the orbiting laboratory about 250 miles above the Earth.
SpaceX is making history by starting a new era in American space exploration.
Bridenstine is optimistic about both SpaceX and Boeing capsules, saying astronauts should begin using them by this year's end.
NASA has awarded SpaceX and Boeing Co $6.8 billion to build competing rocket and capsule systems to launch astronauts into orbit from American soil for the first time since the US Space Shuttle was retired from service in 2011.
Chris Johnson's Forecast | Winter storm potential increasing
A Winter Storm Watch is in effect for much of the I-25 Corridor from Denver to southern Wyoming for Saturday and Saturday night . Accumulations of a trace to one inch of snow are expected from King County southward, the Weather Service said.
For SpaceX, sending an astronaut into orbit would be a culmination of years of hard work and high-risk investment.
If successful, the mission launched on Saturday and the upcoming manned launch will allow NASA to certify the new spacecraft for regular flights to the space station.
He said: "That is something we have to practise in preparation for crewed flight to make sure we're fast in the right spots, and have all the potential medical attention at the right time". While Falcon 9's have completed many successful lift-offs, today's was special because it is the first outing for SpaceX's new Crew Dragon module, created to take astronauts into orbit. But over the longer haul, Musk said, he'd like to open Crew Dragon to space tourists as well. Musk said the redesigned capsule has "hardly a part in common" with its predecessor.
Those Soyuz contracts were set to run out in 2019 and NASA recently moved to secure a couple more seats for late 2019 and the spring of 2020 in case Boeing and SpaceX aren't ready this year.
"We're going to take it day by day", Bridenstine said of the timeline. He marvels at how the Dragon has just 30 buttons and touch screens, compared with the space shuttle cockpit's 2,000 switches and circuit breakers.
"The next big leap in a new chapter of US human spaceflight systems has left the pad", NASA wrote on Twitter. NASA is providing eight billion US dollars for SpaceX and Boeing to build and operate these new systems. "That would be pretty cool, " he said.