Also, some cargo just isn't nice to have in your passenger compartment. (Bags of fertilizer or pieces of greasy machinery come to mind.) The Avalanche's bed is covered in a tough plastic lining, easily hosed out or just left harmlessly filthy.
The cargo ship was expected to automatically park itself at the Pirs docking compartment on the Russian segment of the space station the following day, but the attempt failed and the maneuver was aborted.
