NASA is not serious about sending men to Mars
If they were, they would have bought the artificially intelligent autonomous robotic vision system so that they could have cleared the back contamination problem.
They didn't, they haven't, and without it they simply can not get anyone in the health establishment to sign off on the risk.
Of course, this is all a non-issue for you "enthusiasts", but in the real world, and not the world of canvas "Mars suits", things are different...
But this is quibbling. In point of fact, NASA has also done too damn little to assure that man does not go the way of the dinosaur, and this is priority one.
ep