Tino Schmiel

New Miniaturized and Space Qualified Gas Sensors for Fast Response In Situ Measurements

This paper gives a general overview of the development of new miniaturized gas sensors for in situ measurements of molecular and atomic oxygen, carbon dioxide, carbon monoxide and hydrogen applicable for space experiments and instruments. Due to space driven miniaturization and a reference-free measurement principle, these screen printed ceramic gas sensors enable in situ measurements of partial pressures and flow rates in physicochemical processes and environmental control systems (air renewal/control, fuel cells, control of medical/biological processes, human respiratory investigations, etc.). Also, first experiences have been gained in low pressure, under high vacuum and other extreme/unconventional environments, i.e. in pure hydrogen or pure oxygen conditions. The first space application is the space qualified sensor system FIPEX (Flux-φ(Phi)-ProbeExperiments) that has been in operation on ESA’s external platform EuTEF on the International Space Station for about 18 months. Based on some selected results, this paper is intended to illustrate the performed development steps and the broad applicability of these systems. Hence, measurement principles of the sensors, typical calibration characteristics and measurement ranges are presented for the different terrestrial and space related applications.

Characterisation of TEGs Under Extreme Environments and Integration Efforts Onto Satellites

Large heat flows through spacecraft structures, which are caused by the space environment or operational loads and radiated to space, could be converted into electrical power by a thermoelectric generator (TEG). TEGs are advisable for space application, since no moving parts for power conversion are needed. In this paper, we introduce a so-called ‘Assistance System’, which could be integrated into satellites to ensure communication to a ground station or a servicer satellite, delivering data for deorbiting manoeuvres of inactive spacecrafts. As spacecraft manufacturers and operators have to avoid space debris, this might be a promising solution. First, the system design, the operational states and the required power are described. Since commercial available TEGs based on BiTe were developed for terrestrial applications, an investigation of the electrical characteristics under exposure to typical space conditions is required to rate the potential of TEG-use for energy harvesting on spacecrafts. Our analysis shows that such an assistance system to ensure a rudimentary communication and execution of telecommands is feasible; the required power can be delivered by TEGs using environmental and operational induced heat loads within a satellite. This work is funded by the German Aerospace Center (support code 50RM1114). (Potential application and technology demonstration of thermoelectric generators for low power demands in space, 2012).