An Advanced Scheduling Model for Crop Production in Bio-Regenerative Advanced Life Support (ALS) Systems

In this work, a mixed-integer linear programming (MILP) model is developed for advanced scheduling of crop production in bio-regenerative ALS systems. The main objective of the model is to meet the edible biomass demand of the crew diet. In the meantime, it tries to minimize the variation in oxygen generated by crops via controlling planting areas and the planting timetable of the crops taking into account the variability in oxygen released by crops arising from different photoperiod requirements. The model tries to minimize the cost of regulating the level of oxygen and carbon dioxide within the tolerable range in the crew cabin. If, for example, there is excess oxygen in the crew cabin, then it should be removed at a cost, which may/should be different than re-supplying oxygen if there is a deficit. A similar scenario will apply for carbon dioxide. The model is also capable of keeping track of the loads of other key elements, including energy, humidity due to crop growth, etc., without taking them into account in deciding the schedule, as a first-cut model.