Performing assessments is one way that human factors engineers conduct research. We build either physical or virtual mockups to study the subjects' body position, visibility, hand and tool clearance, reach issues, and translation paths. For physical mockups we try to find subjects that are 5th percentile female and 95th percentile male in stature. For the rocket, the designers are required to design components that meet certain human factors requirements. The HFE team works to ensure that the ground crew can do their jobs with minimal risk to themselves or to the vehicle.