At 9:56 AM EST, the SpaceX Dragon capsule became the first commercial vessel to rendezvous with and be captured by the International Space Station. ”Looks like we got us a Dragon by the tail,” reported Pettit, as applause broke out at ISS and SpaceX mission control.
During its approach to a 30 m distance, Dragon ran into a small problem when it started seeing excess reflection off of the Japanese Kibo module. SpaceX was able to adjust the Dragon’s lidar field of view, narrowing it to exclude most of the reflection. Lidar is used for range finding so the vessel can measure the distance from the docking point.
Dragon then held at 30 m to ensure that the grappling maneuver would be completed when the ISS was in daylight conditions before proceeding to the 10m hold point from which ISS crew are able to snag the craft using a robotic arm. Astronaut Don Pettit did confirm with mission control that it was at their discretion whether to move forward with a grapple under night conditions.
With ISS mission control confirming every step along the way from Houston, and frequent status updates from Andre Kuipers aboard ISS, the operation proceeded smoothly and deliberately. Dragon closed to 10 m and the final go for capture was issued by mission control at 9:49 AM EST. ISS was advised that the Dragon was operating off on only one of its two lidar and any malfunction in that lidar would result in an automatic abort. No abort was necessary, however. Pettit reached out with the 17.7 m robotic arm, capturing the vessel at 9:56 AM EST.