I have no issue with being concerned over the back contamination issue. I have issues with demanding unreasonable measures to prevent back contamination. Nothing is foolproof. There is always some finite risk remaining. Civil, electrical, mechanical, aerospace, and chemical engineering all have to deal with meeting standards of acceptable risk in any task with associated risk (and most do have some risk). Given the very low risk assessment of experts on this topic it makes no sense to take extraordinary precautions vastly inflating the cost of the mission. It is particularly silly to engineer something with a lower risk of failure at one mission point only to increase it at others.

I also have issues with people with an obviously low understanding of science trying to dictate technical decisions. Do you honestly think BD's ability to follow a logical train of thought in microbiology is a whole lot better than his ability in physics? There is a huge difference between memorizing details and being able to understand their implications.

I'd also be thrilled if we find life on Mars contrary to the BS spouted by you know who. I think it will drive manned science missions to Mars even if it delays colonization and it is one of the two key reasons I'm interested in Martian exploration.

Regards,
Mark