Astronauts at the ISS have now boarded the capsule of the Dragon, which carried a dummy pilot and 90kg (200lbs) of supplies on its test flight.
Dragon's hatch is set to be closed at 12:25 PM EST (17:25 UTC) on Thursday, March 7.
The Crew Dragon is created to stay docked to station for up to 210 days, although the spacecraft used for this flight test will remain docked to the space station only five days, departing Friday, March 8. The three station astronauts had front-row seats as the sleek, white capsule neatly docked, a little early no less.
TV cameras on Dragon, as well as the space station, provided stunning views of one another throughout the rendezvous. Shortly after the docking, Ripley was joined by the three astronauts now living on the ISS who donned precautionary oxygen masks to check the atmosphere aboard.More news: China agrees on solution to Tesla customs issue
Behnken said he was "super excited" by the Dragon successfully docking at the ISS.
"We want to maximise our learning so we can get this stuff ready so that when we put crew on, we're ready to go do a real crew mission, and it'll be the right safety for our crews".
The mission was supported by NASA and culminated in the Dragon automatically attaching itself to the space station, almost 260 miles above the Pacific ocean, north of the New Zealand coast. Cargo Dragon must be manoeuvred with the station's robot arm.
Hours later, crew members are expected to open the capsule's hatch and hold a welcome ceremony for the craft. SpaceX's new crew capsule arrived at the International Space Station on Sunday, acing its second milestone in just over a day.More news: Richardson International barred from shipping canola to China
International Space Station's Harmony module forward port via "soft capture" at 5:51 a.m. EST while the station was traveling more than 250 miles over the Pacific Ocean, just north of New Zealand. Once they determined that the air inside the Crew Dragon was safe, they swung the door open and allowed it to mix with the air inside the space station.
The dummy pilot is a mannequin nicknamed "Ripley" after Sigourney Weaver's character in the Alien films.
It will spend five days docked to the orbiting outpost, before making a retro-style splashdown in the Atlantic next Friday - all vital training for the next space demo, possibly this summer, when two astronauts strap in. Engineers will be carefully watching sound, vibration and other stresses on the spacecraft, while monitoring the life-support, communication and propulsion systems. In the meantime, NASA is paying two companies - SpaceX and Boeing - to build and operate America's next generation of rocket ships.
After its shuttle programme was shut down in July 2011 following a 30-year run, Nasa began outsourcing the logistics of its space missions. NASA now pays $82 million per seat.More news: Indonesia, Australia sign long-awaited trade deal