Listening to the local talk radio this morning I heard the host interview a scientist that was involved in the lastest trip to Mars and he talked about Curiosity and all that had to be considered in the landing. Then he went on to talk about getting people to Mars in the future. This is still years off. I guess there is a "think tank" that discusses the whys and wherefores and many "ifs" about going to Mars. Getting there is a lot easier than getting back so one of the options is to go there and stay. The astronauts would never come back to Earth. At least the first couple trips would be one way. This is a serious consideration. Also, a big concern is bringing back bacteria or things for which there is no earthly deterent or none that we could forsee.