A leading critic of space exploration contends that it would be wrong, given current technology, to send a group of explorers to Mars, since the explorers would be unlikely to survive the trip. But that exaggerates the risk. There would be a well-engineered backup system at every stage of the long and complicated journey. A fatal catastrophe is quite unlikely at any given stage if such a backup system is in place. The reasoning in the argument is flawed in that the argument ['infers that something cannot occur merely from the fact that it is unlikely to occur', 'rejects a view merely on the grounds that an inadequate argument has been made for it', 'draws a conclusion about what must be the case based on evidence about what is probably the case', 'infers that something is true of a whole merely from the fact that it is true of each of the parts']