"We are so excited to have you aboard" - the crews of the dragon capsule and ISS meet
Although this was SpaceX’s third crew flight for NASA, it was the first to use a vehicle that’s flown before - an essential part of the billionaire's push to the moon and Mars.
The dragon capsule arrive at the International Space Station a day after launching from NASA’s Kennedy Space Center in Florida.
The Dragon capsule docked with the station 260 miles (420 kilometers) above the Indian Ocean.
SpaceX's recycled rocket docks with the International Space Station
The new arrivals, from the US, France and Japan, will spend six months at the space station.
They’ll replace four astronauts who will return to Earth in their own Dragon capsule on Wednesday.
It was the first time two SpaceX crew Dragons were parked there at the same time, practically side by side.
"We are so excited to have you aboard," radioed the space station’s commander, Shannon Walker.
The Dragon capsule was used for SpaceX’s first crew launch last May, while the Falcon rocket soaring Friday hoisted crew two in November.
Watch the SpaceX launch from Florida on Friday:
NASA astronauts Shane Kimbrough and Megan McArthur, the commander and pilot of the arriving Dragon, were on hand to take control of the docking if needed.
But the autonomous system did its job, much like a self-driving car, connecting safely with the space station.
Also checking is France’s Thomas Pesquet and Japan’s Akihiko Hoshide. Both have lived on the space station before, as has Kimbrough. It's a first visit for McArthur.
Pesquet is the first European Space Agency astronaut to ride in the Crew Dragon spacecraft.
For the next four days, the space station will be home to 11 astronauts, just shy of the record of 13 set during NASA’s space shuttle era.