It is the first crewed NASA mission aboard a privately built spacecraft.
A SpaceX vessel carrying four astronauts has docked with the International Space Station (ISS).
The three American and one Japanese astronauts on board the craft will stay among the stars until April 2021.
ISS astronaut Kate Rubins said “Oh, what a good voice to hear” when she first made radio contact with the Dragon’s commander Mike Hopkins.
The mission is the first crewed NASA flight to space aboard a privately built vessel, with Elon Musk’s SpaceX developing the capsule.
When a replacement crew is sent to the ISS in April, they too will ride aboard a SpaceX ship.
Boeing is also set to start providing transport for NASA in the future.