Oxygen production on Mars: A figure-of-merit approach

A new approach is described toward evaluating the overall system performance in space missions; the objective is to demonstrate a new quantitative tool that can effectively synthesize and display the big picture. It considers a large number of individual components and factors that influence the big picture. The approach was found to be valuable in evaluating various options that must be considered in choosing one or more final ones. The application is especially suited to evaluate missions that consider ISRU. The Figure-of-Merit (FoM) can be different for different missions. In fact, it should be different for different priorities. Simple mass at launch, mass at the moment of departure from LEO, the payback time, the mass returned to LEO, the overall life-cycle costs, etc. are possible indicators of the FoM. After mentioning all of these possible definitions, the FoM for various historical missions will be presented. The FoM of a simple Mars Sample Return (MSR) mission is next presented. It is shown that the FoM is not only higher for missions employing ISRU, but that even among ISRU missions, several mundane propellant combinations are more desirable than the highest-performance propellants.