Design of Spaceflight Hardware for Plant Growth in a Sealed Habitat for Experiments on the Moon

Plant growth experiments on near-term lunar landers need to be relatively small, lightweight, and self-contained. Here, we report on the design of a ~1 liter volume (1U Cubesat size) hermetically sealed habitat suitable for plant growth experiments during the first 10 days of seedling development of Arabidopsis thaliana and Brassica nigra. Images from a single interior camera show germination and provide quantitative data on seedling height, leaf area, and circumnutations. After 10 days with illumination from LEDs, the photosynthetic area of Arabidopsis cotyledons per seedling reached 300 mm². Seedling height, inferred from the overhead camera using reference markers, reached was 15 ± 5 mm. Robust circumnutation in seedlings was observed. CO₂ increased as expected due to respiration in the seeds during germination reaching levels of 5000 ppm after 3 days before declining to 3000 ppm on day 10 due to photosynthetic uptake. No CO₂ was added to the sealed chamber during the experiments. These results show that fundamental studies of germination and initial growth can be conducted in a small volume (1 L) hermetically sealed unit with only an overhead camera and CO₂ sensor. Hardware based on this approach would be suitable for lunar experiments on robotic landers.