The deuterium abundance is five times that of Earth. Even at present launch rates that would be a profitable business. Also, Mars has undergone the same hydrological and volcanic processes that we have, so it undoubtedly has large untouched reserves of gold, platinum, copper, silver - all the metals that are important to civilization and industry. Also, in the long run, the Martians will probably develop many technological advances, which will be driven by need, like the situation in America in the 1700s.

There is a gigantic amount of scientific justification. Mars is a fascinating world, with canyons, gullies, channels, tremendous volcanoes. It certainly had and may still have water. An amazing world with almost unlimited scientific possibilities.

As daver said, the Mars resources are the beauty of the plan. Before you leave Earth, you have a fully fueled ERV with several tonnes of water and air waiting for you on the surface. If there is a failure, you don't have to go. And there is a backup ERV if the first one fails or you land too far away from it.

With a functioning reactor and chemical plant, it is possible to produce 50 times the amount of oxygen necessary for breathing for all four crew members.



Congress.



On the contrary, that would be more than worth it. By discovering life on Mars, besides knowing that we are not alone and that Mars had an environment conducive to life in the past (or may still have one), it will let us know the differences between what Earth life is and what life is. This would cause revolutions in biology and probably aid in finding cures to disease.

A reasonable amount of time.

Totally disagree. The limitations of Mars robotic exploration have to be placed in context. Robots are fine on Mars for photographic surveys, seismology, meterology, and limited geochemical science. But searching for fossils, let alone extant life, requires intelligence and versality of an entirely different type. Fossil hunting requires heavy work - to do it for real, digging trenches and hammering rocks is required. So is fine work- splitting layers of shale to look for life between layers. It also requires complex perception. Sojourner and Athena have no manipulative capablities. Athena cannot travel over 100 meters a day. Both types of rovers, indeed, most any type of robot would be stopped dead by a boulder field or slope that would easy for a five year old.

Rovers and robots of other types are no substitute for real live scientists. You could parachute thousands of MER-type rovers onto Earth, and it is a fair bet that they might not find any fossils, at least not before the arrival of the next ice age, when they would be crushed by the glaciers which they would not be able to outrun.

Looking for extant life has much greater demands. No robot that will available in the next fifty years will be able to find groundwater or do any serious subsurface studies of Mars, where the life or paast life is likely to be found. First, a spot must be chosen with radar. Then a drilling rig must be set up - and the complex operations required to set one up totally rule out the robots which will be available for at least the next 25 years. And even if a robot could do this, it is doubtful that it could then analyze the life and the context of where it was found. But a human can easily do all of these, and more. A trained geologist's eyes are orders of magnitude beyond what a rover could tell us. Take the Mini-TES instrument on MER. It tells us of the composition of rocks. Now, a trained geologist could operate such an instrument (of far more complexity, owing to the 500 kilogram margin for scientific equipment) and tell us exactly what it was we are looking at. No robot could do that, because robots cannot think.

As a final example, take an Apollo mission, Apollo 15. The entire ALSEP would probably be too complex for modern robots to set up. Could these same robots than explore the region? It is doubtful that such finds as the Genesis rock or things like removing stuck drills from the surface could be done by robots. On Mars, humans will simply be so much better than robots that comparisons become useless. Even collecting samples and core samples on Mars (hundreds of pounds at least) would be far beyond the ability of robots. And could these robots also explore the region, take thousands of pictures, and generally perform all of the scientific functions that humans can?

In a word, no.

The Mars Direct plan which I have been talking about allows 7.7 metric tonnes of supplies. The multiple Saturn Vs may add complexity but decrease the risk greatly. If there is not a fully funcitoning, fueled EArth Return Vehicle on the surface of Mars waiting for you, you don't have to go anywhere. Plus there is one following you in case of trouble. The simply work out. Hard to believe, but true. The Hab carries about 3 years of supplies for the entire crew, enough time for a third ERV to be sent out even if both ERVs end up too far away from the Hab. Plus it carries a combustion-power pressurized rover that has a one-way range of 1,000 kilometers, and two open rovers. The scientific potential is tremendous. The fuel, as I explained, is made by the ERV. It's already there, on Mars. No need to haul it out with you. The total weight of the Hab, including the supplies, equipment, and crew, is about 28 tonnes. Within the range of a Saturn V-class vehicle to send out on a 180-day trajectory to Mars.

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"Too low they build, who build beneath the stars". - Edward Young, 1745