At 1525 UTC, the command to maneuver to the pre-latch position was given. The solar arrays on the Dragon have to be turned to their zero position to allow the berthing.
Don Petitt is operating the Canadarm (SSRMS) and Joe Acaba is the Common Berthing Mechanism (CBM) operator.
At 1548 UTC, the command to proceed with first stage capture was given. Nominal 1st stage capture is complete. Go to take the SSRMS to “limp”. This takes the stress of the docking mechanism. With the SSRMS “limp”, GO for 2nd stage capture was ordered.
And at 1602 UTC, 2nd stage capture is complete and Dragon is officially secured to the International Space Station.
The first commercial spacecraft to be launched to the ISS has completed its berthing procedure.