The mission marks SpaceX's first "operational" mission for the Crew Dragon, the cabin which will carry the astronauts, from United States soil.
The crew for the flight to the International Space Station includes three American astronauts - Victor Glover, Shannon Walker and the mission commander, Mike Hopkins, a U.S. Air Force colonel who is to be sworn into the fledgling U.S. Space Force once aboard the orbiting laboratory.
Originally, the Crew-1 mission meant to start their journey on Saturday, but the launch has been pushed back to Sunday due to weather interference caused by Tropical Storm Eta.
Late Friday afternoon, the mission team made the decision to delay the launch by a day, due to the expected weather conditions during Saturday's launch window.
The schedule adjustment was made to ensure that the weather is suitable for the recovery of Falcon 9's first-stage booster following the launch.
Called Crew-1, it's SpaceX's first full-length mission for NASA.
The four astronauts on board will spend six months on the International Space Station. Six months after his historic flight to the ISS, it wants to U.S. company SpaceX by Tesla founder Elon Musk* This is the first time to send a manned rocket into space on a six-month routine mission. When asked by a Twitter user about his symptoms, he said he had those of a "typical cold".
Norm Knight, a deputy manager at NASA, said the guidelines are rigid for restricting access to astronauts before flight in order to keep them safe and healthy.
Although Crew-1 will be SpaceX's first full-length mission, the company launched people into orbit earlier this year.
The Crew Dragon is scheduled to dock with the ISS starting at about 11 p.m. ET on Monday.
The crew for the historic launch includes a Space Force colonel, a Black pilot leaving Earth for the first time, a woman who has logged almost 4,000 hours in space and a Japanese Aerospace Exploration Agency astronaut.
The timing of the tests appears to be linked to a SpaceX launch at which Musk was likely hoping to meet with the four astronauts involved, as he did with Robert Behnken and Douglas Hurley before the successful launch in May, as the New York Times reports.
Basically, the winds were expected to make a Saturday launch more hard, and the water surface conditions out on the Atlantic would have made recovery of the Falcon 9 first stage more treacherous.
Cape Canaveral: A SpaceX Falcon 9 rocket and Crew Dragon capsule is rolled into Launch Complex 39A. The company plans to reuse the first-stage booster for its next crew launch, next spring.
But SpaceX's success won't mean the USA will stop hitching rides with Russian Federation altogether, said Bridenstine.