A SpaceX capsule occupied by two NASA astronauts hooked up with the international space station on Sunday, marking a key victory in an emerging commercial partnership with the U.S. aeronautics and space agency.
"Welcome home," posted Jim Bridenstine, NASA's administrator on Twitter following the link up. "America’s two favorite dads in space have docked" to the space station.
The SpaceX Crew Dragon Endeavor spacecraft was carrying NASA astronauts Robert Behnken and Douglas Hurley, who lifted off late Saturday afternoon on the SpaceX’s Falcon 9 rocket from the Kennedy Space Center in Florida.
Docking at the station’s Harmony port shortly after 10 a.m. ET Sunday, the spacecraft was flying about 262 miles above the northern border of China and Mongolia, according to NASA.
The hatch between the space station and the Dragon Endeavour was then successfully opened at 1:02 p.m. ET, and Hurley and Behnken entered the station, joining astronaut Chris Cassidy, and Anatoly Ivanishin and Ivan Vagner of the Russian space agency Roscosmos.
“It was a tremendous day in mission control as we watched the Dragon approach and then dock, and the hatch open and have Bob and Doug come forward in the space station," said the station's director, Mark Geyer, later in the afternoon.
Sending astronauts to the space station marks a breakthrough in NASA’s commercial space program partnering with aerospace companies such as SpaceX and Boeing (BA) - Get Report to create and run a new spacecraft.
Connecting with the space station follows SpaceX's earlier success of docking on the station using an unmanned Crew Dragon spacecraft. It also comes months after SpaceX completed its launch-escape demo -- another important step that at the time contrasted with BoeingSpace's failed trip that mistimed an orbit.
“Today a new era in human spaceflight begins as we once again launched American astronauts on American rockets from American soil on their way to the international space station, our national lab orbiting Earth,” said Bridenstine in a statement over the weekend. He noted that the launch of the commercial space system is an "important step on our path to expand human exploration to the Moon and Mars.”
The test flight aims to "validate" the SpaceX crew transportation system, including launch, in-orbit, docking and landing operations, with the goal of certifying the craft for regular crew flights to the station as part of NASA’s commercial crew program, according to NASA.
Musk called the flight a "dream come true" in a statement over the weekend.
The mission not only marks the second arrival and "autonomous docking" to the space station for a Crew Dragon spacecraft, but the first time any commercially built craft has delivered astronauts to the "orbiting laboratory," according to NASA.
This story is being updated.