Hah hah, that contamination thing is gonna bite them in the ass right quick. You'll see. Well, if you decide to continue the show.
They actually have a robot called the MALP they send through the stargate before any team goes through. It checks atmosphere, temperature, and many other variables. It of course, happens to fail on occasion, but it does it's treaded, robot-y best. Essentially, SG1 through SG20 visit the worlds that have been scouted by the MALP.
Sometimes they send a flying version through. UAV MALP. I think the UAV MALP is pretty neat.
Great CGI can't carry a show. if it did, actors would be out of a job.