A mobile surface cleaning robot including a robot body having a forward drive direction, a drive system supporting the robot body above a floor surface for maneuvering the robot across the floor surface, and a robot controller in communication with the drive system. The robot also includes a collection volume supported by the robot body and a cleaning module releasably supported by the robot body and arranged to clean the floor surface. The cleaning module includes a first vacuum squeegee having a first duct, a driven roller brush rotatably supported rearward of the first vacuum squeegee, a second vacuum squeegee disposed rearward of the roller brush and having a second duct, and a third duct in fluid communication with the first and second ducts. The third duct is connectable to the collection volume at a fluid-tight interface formed by selectively engaging the cartridge with the robot body.