Mark,

There's more people than Barry worried about this, so running him into the ground won't work. Mars supporters are faced with a dilemna: the search for life is one of the justifications for Mars expenditures, but if its found the back-contamination problem gets very serious.

(Personally, call it the romantic in me, but I'm hoping for something more than sludge in some sub-surface brine pool.
I kind of hope Sir Arthur is right about some kind of cacti.)

Since the problem remains hypothetical to a large degree, the other folks I listed are not that concerned. MSR is some 10 years away, and they have more pressing business.

Should the problem not remain hypothetical, as in the case of manned Mars flight, they will all make sure that they have sufficient power to take the steps which they feel necessary.

It won't take anything more than one statement to the press for them to ensure that they recieve that power, if they have decided that NASA's Planetary Protection Officer, whoever he is at that time, (remember, this is at least 10 years from now) is not doing his or her job.

As for time, I can't believe that I'm spending any time of this at all now. Mars Sample Return is no sooner than 2010.

Back-contamination, like radiation, is a real problem in the real world. But then so are impact events.

EP