The Dragon was on its way to a 30-meter (98-foot) checkpoint when the team at SpaceX's Mission Control in Hawthorne, Calif., ordered the spacecraft to retreat to a distance of 70 meters (230 feet). NASA's Mission Control said the SpaceX team wanted to correct bad laser sensor readings that the Dragon was getting from a stray reflector on the station's Japanese-built Kibo laboratory. To work around the problem, SpaceX narrowed the field of view for the laser sensor so that it wouldn't pick up light from the offending reflector. Dragon then returned to the 30-meter checkpoint and moved in for the final approach.
When the craft reached a distance of 10 meters (33 feet), NASA astronaut Don Pettit used the station's 17-meter-long (60-foot-long) robotic arm to grab hold of the Dragon's grapple attachment at 9:56 a.m. ET.
"It looks like we've got us a Dragon by the tail," Pettit told Mission Control. Applause broke out at NASA's Johnson Space Center as well as at SpaceX in Hawthorne.
Pettit joked that the operation went so smoothly it felt like a computer simulation. "Looks like this sim went really well," he said. "We're ready to turn it around and do it for real."
It took another couple of hours to pull in the Dragon and get it fully hooked up to the station's Harmony module. NASA and SpaceX refer to this operation as a "berthing" rather than a "docking," because the Dragon is being passively pulled in rather than powering itself into the docking port.
The completion of berthing at 12:02 p.m. ET put SpaceX in the company of four governmental space ventures — NASA, the Russian Federal Space Agency, the European Space Agency and the Japan Aerospace Exploration Agency — that have built vehicles capable of hooking up with the space station.