All previous attempts to send missions to Mars have been unmanned. Of the 40+ missions since 1960, about 40% could be deemed a success. Transporting humans to Mars obviously will add to the complexity. Everything about a Mars mission is more difficult: the time in space required, at least 24 months, means longer exposure to radiation for humans and hardware, longer opportunity for hardware parts to fail, larger amounts of stores including fuel and gases to carry, and the similar risks faced by the Apollo mission for landing on the planetary surface and subsequent take-off. Add to these the time and distance factors, making rescue missions extremely unlikely to be effective. Of the previous handful of Apollo expeditions carrying humans, one (Apollo 13) almost ended in disaster when an incorrectly-engineered part failed, and was saved only by ingenuity and persistence by ground and flight teams, and the integrity of the surviving systems. Even on the ISS, the excellent science and engineering invested in the manufacture of components does not prevent the failure of water recycling systems, ammonia pumps, solar panel bearings, spacesuit water containment systems, main bus switches, torn solar panels, and computers. Then there is the unlikely but ever-present risk of collision with high-relative velocity objects in space. Astronauts, some of the best and brightest, most committed, highly-trained, and adaptable folk, are ready for risk. But what of the ethics of sending people on such a risky mission? Has enough been achieved to significantly reduce that risk? I would argue not. Scientists and engineers approach difficult problems with good design, excellent materials and manufacture, testing and retesting, especially of integration of systems. Then they may add redundant systems, or backup. But to date, a single craft is planned for the mission. It works or it does not. Would it make more sense to send a small flight of craft, at least three, with interchangeable spare parts, crew exchange ability and redundant stores? With more than one landing craft for rescue of a surface crew if necessary, and each craft able to support the entire crew for a return journey to Earth, a super-redundancy can be achieved. The development costs for three craft are the same as for one craft, so that the extra costs are only for crew training, manufacture and launch (probably more processes are accountable). After all, Chris Columbus crossed the Atlantic and returned using three ships. What do Slashdotters think?"
The new finding is based on observations from NASA's Mars Reconnaissance Orbiter, which has been orbiting the Red Planet since 2006. Mars Reconnaissance Orbiter is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., for NASA's Science Mission Directorate in Washington."
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