Carbon based atomic oxygen sensors

Carbon-based sensors have been developed to measure the atmospheric neutral atomic oxygen (AO) flux experienced by spacecraft in low Earth orbit (LEO). Thick- and thin film carbon sensor elements were deposited on an alumina substrate between thick film gold tracks and silver palladium solder pads. A 0 flux is deduced by measuring resistance changes as the carbon film erodes, and applying a simple theory. Measured resistance increases during exposure in a ground-based AO facility compare favourably with theoretical predictions. These sensors appear to offer a number of advantages compared with similar silver-based sensors that have been flown previously, particularly for small satellite missions with significant mass/power constraints.