<div class="htmlview paragraph">The most important CELSS engineering parameters are, in order of decreasing importance, manpower, mass, and energy (<span class="xref">1</span>). The plant component is a significant contributor to total system equivalent mass. In this report, a generic plant component is described and the relative equivalent mass and productivity are derived for a number of instances taken from the KSC CELSS Breadboard Project data and the literature. Typical specific productivities (edible biomass produced over 10 years divided by system equivalent mass) for closed systems are of the order of 0.2.</div>