Human Factors in Equipment Development for the Space Shuttle: A Study of the General Purpose Work Station

Abstract

NASA - Ames Research Center has recently developed a specialized Class II Biohazard contained working space for life Sciences experiments. This work bench, the General Purpose Work Station (GPWS), has been designed for use in the first dedicated Life Sciences Spacelab payload of the Space Shuttle. The experimenter's position and access to the work station directly impact the performance of the procedures. A series of science functional tests were developed by NASA-ARC to determine the capabilities of the GPWS and to reveal the critical points of operator interface. Four procedures were performed three times each by six subjects: mouse handling, a hematology experiment, a plant dissection, and a squirrel monkey observation. Data were collected via video taping and user and observer evaluation forms. Analysis of the voice comments, body posture and movement, and placement of equipment from the video tapes showed clearly the areas needing human factors improvement. The subjective evaluation forms with a five-point acceptance scale, were adequate in the assessment of the test. The user and observer evaluation forms collected information on the observed problems in one-g and the potential problems in zero-g. From the results of the data collected, it was concluded that various hardware features needed to be changed or modified. Immediate problems such as the electronic touch panel configuration were solved. The long term problems of zero-g work surface height and muscle fatigue need to be studied further. In order to answer some of the problems of muscle fatigue, the procedures to operate the GPWS can include appropriate rest and stretch time periods for the operators. In addition, plans are underway to study posture and muscle fatigue at work stations in underwater simulation of zero-g.