Current plans for long duration space missions anticipate the need for self-sustaining habitats, which would include plants for food and atmospheric reprocessing. Growth of food, in turn, necessitates a food processing element. A multipurpose fruit and vegetable processor (MFVP) was designed and built for this purpose by comparing potential technologies using equivalent system mass (ESM) impact, a NASA metric. As an example of selection and evaluation, the concentration sub-unit to produce tomato concentrate is reviewed. Evaporation, and integrated membrane approaches-microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO)-were compared for applicability. Direct RO was selected and tests evaluated operating conditions, maximum concentration and flux decline. Filtration performance parameters were obtained: permeate flux, volume concentration factor (VCF) and power usage. Pressure and temperature were the determining factors in performance and a maximum concentrate of 22.7 degrees Brix was projected. Increases in cross-flow velocity (CFV) added power demand and therefore was found to raise ESM. Added transmembrane pressure (TMP), on the other hand was found to offset power increases by reducing processing time. The study validated the use of ESM as a tool for selecting technologies and proved the usability of RO for the MFVP process. (c) 2005 Elsevier Ltd. All rights reserved.