Biobot: Investigating an Alternative Paradigm for Planetary EVA

One of the biggest burdens on an astronaut when conducting planetary surface operations is the need to carry a portable life support system (PLSS). This unit is typically comparable in weight to the astronaut, and disturbs mobility by displacing the center of gravity of the human in the spacesuit aft and upwards. The additional weight leads to increased energy expenditures, as well as overall reductions in performance and duration. The motivation to minimize the loads on EVA crew served as the inspiration for the BioBot concept: a EVA-companion rover which carries life support for the spacesuit, and supplies the user via self-tending umbilicals. This paper outlines the design requirements for BioBot, and documents the results of a variety of trade studies, including providing self-contained suit life support for various periods of time for safety and local independence, and designs for BioBot configurations ranging from minimal rovers to incorporation into pressurized rovers. Probabilistic risk analyses have examined safety implications of the concept, including options for sharing of BioBots and the effect of extended durations in contingency situations. In addition to BioBot systems analyses and trade studies, a prototype BioBot has been developed at the University of Maryland using a Segway RMP440LE robotic vehicle and UMd MX-C suit simulators. Results of this testing will be discussed as well. The benefits of BioBot go beyond just reducing the mass that an astronaut would be required to carry, as it opens the possibility for using alternative suit components that could enhance mobility. In addition, BioBot could also allow for the use of potentially larger and heavier, but more efficient life support systems that normally would not fit in a PLSS, but could be mounted on a rover. Conclusions and future work will also be presented in this paper.