Another first for SpaceX

As I wrote previously, SpaceX used the Dragon spacecraft's unpressurized "trunk" to carry additional large cargo pieces to the ISS this trip.  The unpressurized trunk section is separated from the main, pressurized, section and is not accessible via the docking hatch.  So the space station's robotic arm had to be used to unload the cargo from the "trunk".  This represents another SpaceX mission first, and clears the way for addition cargo in CRS-3 and CRS-4 later this year and early next year.  Both of these have cargo on the manifest that will fly in the unpressurized trunk.
A really good article about the robotic unloading (and the mission as a whole) is here on the nasaspaceflight.com site.