The timeline in the press kit for the upcoming CRS-9 SpaceX launch says at about 11 minutes after launch, "Dragon's solar arrays deploy", and at 2 hours 19 minutes, "Dragon's Guidance, Navigation and Control bay door opens".
I can imagine that cameras for guidance would be protected behind a door, but it sounds like there is a lot more there!
What all is there in the Guidance, Navigation and Control bay that would need to be exposed to space after the door opens?
edit: I found some pics on line - is this the door in question? The gold structure on the inside surface of the door is different in the two pics - but they both look vaguely antenna-like. What are those?
Above: from SpaceX - click for full size.
Above: from SpaceX DragonLab Fact Sheet - click for full size, or just go see the PDF.