Studying Tardigrades as a Biological Payload Onboard A 3U Nanosatellite in Low Earth Orbit

摘要

The University of Manitoba Space Applications and Technology Society (UMSATS) is developing a scientific payload to study the characteristics and survivability of extremophiles called tardigrades in low Earth orbit (LEO). Tardigrades are microscopic metazoans that are able to convert into a cryptobiotic state in the absence of water, thus enabling them to survive extreme environmental conditions including immense pressure and radiation doses up to six times more than what is lethal to humans. Several other space related studies have been conducted on tardigrades on Earth and in space. However, to date, no study has been conducted to test/observe the characteristics and survivability of tardigrades that are re-animated while in LEO after being exposed to the environmental conditions. We have created a method study tardigrades in LEO inside a 3U nanosatellite. Using Discrete Cosine Transform (DCT) algorithms running on an onboard image processing system, we detect the motion of tardigrades within a micro ecosystem consisting of bdelloid rotifers as food source and lichens as oxygen producers. The algorithm detects if the tardigrades have either aggregated near the provided food source, or if they are distributed throughout micro ecosystem (living chamber). Aggregation indicates directed movement towards the food source thus indicates the health of the tardigrade colony. In order to increase the robustness of the detection algorithms, the tardigrades are genetically modified using enhanced green fluorescent protein (EGFP) which will cause the tardigrades to fluoresce in the presence of ultraviolet light, making them easily distinguishable from other organisms and debris in the living chamber.