Wireless propagation measurements for astronaut body area network

Abstract

Existing space suits use conventional wired sensors that collect very limited physiological data to monitor health of astronauts during missions. Adding more wired sensors would involve significant modifications and complexity to the suit. Deploying a wireless body area network (WBAN) is preferred and would provide a number of advantages such as flexibility in sensor complement and positioning. This paper investigates the performance of intra-space suit wireless propagation using a full-scale space suit model that is built with electrical properties similar to that of a real space suit. The performance is characterized by quantifying the channel path loss at three frequencies: 315 MHz, 433 MHz and 916 MHz. Using a top-hat monopole antenna that is conformal to the human body and excites dominant coaxial waveguide modes, we measure path loss associated with various transmitter-receiver locations. The results demonstrate that the intra-suit environment is quite conducive to radio propagation, although there are substantial differences in path loss for the different frequency bands.