Fatal291 -<br /><br />I do not expect a human being to step on Mars until year 2100 or so. Which, given the advances in medicine, may well be in your lifetime if you are 18 now and live in the developed world. But I know this is not the answer you are looking for. <img src="/images/icons/smile.gif" /><br /><br />There are several reasons for my pessimism. The biggest one is this: NASA can not admit that space is dangerous. Normally in any dangerous activity, be it soldiering, firefighting, or test-flying airplanes, the people in charge decide what level of risk is acceptable, and plan their budgets, training, and operations accordingly. The lower is acceptable risk, the less operation can be carried out on a given budget, and vice versa. The risk level decisions are almost never publicized – on your local fire department’s website you won’t find “we expect X deaths and Y injuries over next decade”, - but you can be sure fire chief has that information, and brings it up at the next municipal budget hearing. And both fire chief and city council know that the only way to bring X (let alone Y) to zero is not fight fires at all. So fire departments balance expected deaths, expected number of fires and available money, and when someone dies they grieve, do their best to learn from the experience, and carry on.<br /><br />The quandary of NASA’s Office of Manned Spaceflight is that it is too much in the public eye, yet does not have a clearly defined purpose. A city can not live without a fire department; nothing drastic will happen to USA if Office of Manned Spaceflight closed tomorrow. Mike Griffin knows that space is dangerous and every once in a while people will die – but he wouldn’t last a week if he went before Congress and said “This mission architecture cost X dollars, has Y percent chance of landing on Mars on schedule, and Z percent chance of killing one or more astronauts. Double the X, and Y will increase such and such, and Z will decrease such and such.” Even though i