Barry,

I have gone over how you have misinterpreted your "references" on numerous occasions. Your response usually consists primarily of talking about Mars Society Habs. That pretty much sums up how much you really know and understand about these topics. This latest post is another classic case of mindless cut and paste. Once again you missed some key contradictory comments while you thought you were supporting your case.

"The SSB proposed relaxing the planetary protection requirements for those Mars lander missions that do not contain life detection experiments, but maintaining Viking-like requirements for those missions that do contain life detection experiments."

It's quite obvious from this the focus is on not blowing the science of a life detection experiment, not overwhelming concern about Earth life contaminating Mars. The cat is already out of the bag there anyway if that were an issue due to Russian Mars probes. Mars Society Steering Committee member and PS director Chris McKAy has shown more concern about that issue while still supporting a manned mission.

Human missions do pose a risk of contamination, but they would also be far more capable than the robotic missions we send out to detect contamination. The protocols we use to ensure sample integrity on Earth for human work could be adapted on Mars. We would certainly need to be careful to conclude anything about existing life through sampling in the area of a human base. Robotic collection of samples suspected of containing life maintained under conditions to avoid contamination would probably be needed as controls. On the other hand humans would be free to look for fossil and chemical evidence of past life without concern for contamination.

It shouldn't take 100's of years to clear the entire planet for a human mission either even if people bought your argument. They could simply land near where a previous probe already landed and found no evidence of life.

One reason for human missions is to search for evidence of life where less capable robotic missions have failed to find it or to followup with more detailed studies if it is found. When we find unusual life on Earth we don't quarantine it. We send in biologists to study it. Even pathogens are cultured and studied. Your whole outlook on Mars life is at odds with how biological and medical research are conducted.

Regards,
Mark