Fault-Tolerant Platform for Intra-Spacecraft Modular Wireless Sensor Network

Abstract

Wireless sensor networks are becoming ubiquitous in terrestrial applications. In this thesis we present a platform for wireless on-board spacecraft sensor networks with focus on the sensors that bring high 'added value' to existing space systems while becoming wireless. A novel multi-gateway architecture that uses dual hardware redundancy is proposed in this thesis. The concept of an autonomous (self-describing) modular sensor node (i.e. exchangeable sensors and power sources) is investigated and a general provision is made for future implementations. Electronic Datasheets (EDS) are considered as a way to allow fast self-reconfiguration of the sensor node and its energy device. Next, a survey on commercial off-the-shelf components (COTS) wireless sensor network hardware and protocols is conducted. A test with a Zigbee-based gateway switchover is performed and its impact on the wireless communication is investigated with or without check pointing. The results of this thesis show that current wireless sensor network systems can be adapted for several space-borne applications and can significantly shorten integration-test time (during spacecraft assembly) with the help of a modular based sensor system. Additionally, the limitations and future directions are discussed to provide possible future implementations of the next generation wireless sensor networks for intra-spacecraft applications.