Performance of the CELSS Antarctic Analog Project (CAAP) crop production system.

Regenerative life support systems potentially offer a level of self-sufficiency and a decrease in logistics and associated costs in support of space exploration and habitation missions. Current state-of-the-art in plant-based, regenerative life support requires resources in excess of allocation proposed for candidate mission scenarios. Feasibility thresholds have been identified for candidate exploration missions. The goal of this paper is to review recent advances in performance achieved in the CELSS Antarctic Analog Project (CAAP) in light of the likely resource constraints. A prototype CAAP crop production chamber has been constructed and operated at the Ames Research Center. The chamber includes a number of unique hardware and software components focused on attempts to increase production efficiency, increase energy efficiency, and control the flow of energy and mass through the system. Both single crop, batch production and continuous cultivation of mixed crops production studies have been completed. The crop productivity as well as engineering performance of the chamber are described. For each scenario, energy required and partitioned for lighting, cooling, pumping, fans, etc. is quantified. Crop production and the resulting lighting efficiency and energy conversion efficiencies are presented. In the mixed-crop scenario, with 27 different crops under cultivation, 17 m2 of crop area provided a mean of 515 g edible biomass per day (85% of the approximate 620 g required for one person). Enhanced engineering and crop production performance achieved with the CAAP chamber, compared with current state-of-the-art, places plant-based life support systems at the threshold of feasibility.

Solid waste processing in a CELSS: nitrogen recovery.

Life support technologies are being developed for long-duration space missions at NASA Ames Research Center as part of the Controlled Ecological Life Support System (CELSS) Program. The primary goal of the CELSS Program is to develop small-scale ecological systems, a CELSS, that mimic ecological systems on Earth. This small-scale replica CELSS can provide all of the necessary life support functions and recycle nearly 100% of the waste products. A CELSS will use plants to purify air, clean water, and generate food for a human habitat. Human and plant waste products will be converted to useful products and reintroduced into the plant and human habitats for consumption. Both physical/chemical and biological waste-processing systems may be utilized to recycle waste materials. Recovering nitrogen from waste products is a major concern because nitrogen is an important nutrient for plants and humans. This article will outline plant selection requirements and waste-processing requirements, characterize waste streams, and discuss the potential physical/chemical waste processors used to process the wastes and the fate of nitrogen as a result of the process employed.