Wrapping up a two-day rendezvous, acaught up with the International Space Station on Saturday, bringing 5,000 pounds of equipment and supplies to the outpost including a new docking mechanism that will provide a second port for commercial crew ships being built by Boeing and SpaceX.
Sailing 260 miles above the southern tip of South America, the unpiloted Dragon pulled up to within about 30 feet of the lab complex and then stood by while astronaut Nick Hague, operating the station's Canadian-built robot arm, locked onto a grapple fixture.
Flight controllers at the Johnson Space Center in Houston then took over arm operations, remotely controlling the space crane to pull the Dragon in for berthing at the Harmony module's Earth-facing port. The hatch opening is expected Sunday, but the astronauts could move that up depending on their weekend schedule.
Launched Thursday from the Cape Canaveral Air Force Station atop a Falcon 9 rocket, the Dragon was loaded with 1,600 pounds of science gear and equipment, 830 pounds of spare parts and other station components, 600 pounds of crew supplies and another 440 pounds of spacewalk gear, including refurbished suit components.
The 1,170 pound docking adapter was carried into orbit mounted inside the Dragon's unpressurized trunk section. It will be removed by the station's robot arm later and attached to the Harmony module's upper port during a spacewalk next month.
With the Dragon capture complete, engineers and technicians at the Baikonur Cosmodrome in Kazakhstan will set their sights on readying a Russian Progress cargo ship for launch Wednesday that will bring another 2.7 tons of supplies to the station.
Liftoff of the Progress MS-12/73P spacecraft is planned for 8:10 a.m. EDT Wednesday (6:10 p.m. local time) with docking at the Russian Pirs module expected just two orbits later, at 11:35 a.m. The Progress is loaded with 2,611 pounds of dry cargo, nearly 1,000 pounds of water, 164 pounds of propellant and 110 pounds of oxygen.