From Mars with Love

1) Sample return missions from Mars are feasible in the 1980's. 2) The least expensive missions (direct sample return without sterilization) may be criticizable because of the possibility of back-contamination, although upgrading the handling and containment facilities could make unsterile return acceptable. 3) Sample sterilization decreases the total scientific value appreciably, depending on the measurements to be made. Geology is least affected and biology and organic chemistry are most affected. 4) Quarantine in earth orbit, in the same sense as for the lunar samples, would not be feasible without very large increases in cost. Orbital quarantine facilities, either automated or manned, would be very expensive, risky, and of limited use because of size limitations. 5) Orbital quarantine may be feasible if the sample is split, part of it sterilized and returned to the earth for study, and the remainder studied for pathogenicity in the automated mode as best we can in the limited space available in orbit. Ground studies of sterilized material plus "live" studies in orbit may convince us of the safety of returning the remaining sample to the earth under carefully prescribed conditions. 6) Additional unmanned, Vikingtype missions to Mars can add considerably to our knowledge about a martian biota, or its absence, and thus increase the likelihood of being able to return an unaltered sample safely to the earth.