What is it that makes people think that a bacteria from Earth , having somehow gotten in contact with the MSL spacecraft, would be alive after a trip through space of many months, or...a trip through space of a minute, if not protected from that environment???
I mean, let me pick on someone alot bigger, say, YOU, and here's what I'll do.
I'll contaminate our next craft with you, and just tape you to the exterior surface, or maybe secure you in the battery compartment.
Then, you'll be launched into orbit aboard an Atlas V, and be boosted a couple hours later on a trajectory to Mars.
You wouldn't survive into orbit. You'd have been screaming for mercy in a minute, as the G load built up to suilly levels, and within a few minutes, would be so well up through the atmosphere that you'd pass out, and die in minutes as near vacuum and freezing cold attacked your body, as well as the 4-5 G load.
That's about the truth. So, think about that poor microbe "contaminating" the Rover spacecraft!!!
How's he making it, when you couldn't even get into Earth orbit???
THen the very,very,thin atmosphere of Mars takes hold of our intrepid traveler.
Go on !Its getting intresting.