Wireless Compose-2: A wireless communication network with a Ballistocardiography Smart-Shirt experiment in the ISS Columbus module

This paper introduces Wireless Compose-2, which is an experiment for the International Space Station (ISS) in order to demonstrate the provision of a flexible and adaptable wireless network infrastructure integrated in a commodity item to conduct and execute low-power, low-weight and wireless experiments in the scientific and medical domain. Recent work revealed a great potential in utilizing wireless sensor networks (WSN) in space habitats; however, the focus was only placed on sensing in the narrowband Industrial Scientific and Medical (ISM) 2.45 GHz band. This work extends these capabilities by utilizing impulse radio ultra wideband (IR-UWB) for ranging and evaluates the use of internal light sources for energy harvesting to drive the sensor nodes. The focus of the Wireless Compose-2 experiment is on the operation of the scientific experiment BEAT (Ballistocardiography for Extraterrestrial Applications and long- Term missions), which is a demonstration of novel ballistocardiography (BCG) sensors to monitor important cardiovascular parameters in a microgravity environment. Integrated in a Smart-Shirt, it will form a Body Area Network and makes use of the IR-UWB communication to transmit the data to the network. This paper describes the operational scenario, and the hardware as well as software concepts are presented in detail. Finally, the expected results are outlined with the focus being on the analysis of the different aspects that will help to identify new applications for future space missions.