Concept Evaluation and Selection

After the completion of the concept generation phase, each solution was evaluated to determine the standout concepts.

Initially, all ideas were evaluated on the safety of the astronauts using the machine in a lunar environment.  None of the ideas in the concept generation phase would be able to be operated safely and therefore did not need to be vetoed based on safety factors.  Next, several solutions from the Mindmap were removed based on ineffectiveness. The “non-water” solutions were the first to be ruled out.  Ozone, UV-light, and static/electric all have very low cleaning ability and were therefore determined to be unsuitable for cleaning soiled fabrics.  Chemical cleaning was ruled out because it uses a large volume of consumables.  Next, compression cleaning and compression drying were ruled out due to the “crushing” action on the clothes.  The rubber tubes and fittings present on astronaut’s cool-suits would be too easily damaged by any type of compression process.  Heating as a drying process was not considered because a heating element of any type is not allowable in the habitat’s oxygen-rich environment.  Steam was eliminated for this same reason.

Pugh Chart


Following the elimination of the non-practical solutions, a total of four water cleaning processes and three drying processes remained.  The combination of these resulted in twelve possible concept variants.  The “spinning-spinning” combination is already seen in both vertical-axis and horizontal-axis washers, so this appears twice for a total of thirteen variants seen in Table 2.