ABSTRACT

This paper analyzes the three major approaches to the Mars Sample Return mission; direct return using propellants transported from Earth, Mars orbit or interplanetary rendezvous with all propellants transported from Earth, and direct return from the Martian surface using in-situ propellants. It is found that the direct return with terrestrial propellant fails on the basis of cost, while the orbital rendezvous approaches fail on the basis of risk. In contrast, the approach employing direct return utilizing indigenous propellants appears to be attractive on both a cost and risk basis. In addition, the in-situ propellant technology is found to offer maximum benefits for follow-on missions, including robotic Mars hopper science missions and human exploration missions.