Setting aside the fact that it can take a space probe six months to reach Mars, and a space vehicle the size of the Mars Global Surveyor up to 10 months, could Man reach the planet and actually set foot on Mars today?
It’s smaller than Earth, at 6787km diameter, and a mass of only 6.42 x 10/23kg, but you could land on it. Time would pass rather slowly, a Martian year being 686.98 Earth days, and it might be a bit chilly, since the sun is 1.524AU away. But at least you could find your way around, since the highest elevation is Olympus Mons, about 24km above the surrounding lava plain.
Thanks to the Mariner, Viking and Mars Orbital Surveyor missions, we now know more about the Martian atmosphere, than ever before. It breaks down into 95% carbon dioxide, 3% nitrogen, and 1.6% argon. Using spectrographic and other observations, plus calculations of the seasons and sun angles, we can pretty much predict what the temperature is at any given time.
Average temperatures hover in the -60Centigrade range, with summer highs of 20, and polar ice cap lows to -120C. The atmosphere, which is comprised largely of CO2, is only 8 one-thousandths of Earth’s. The winter drop in temperatures over the polar regions, cause part of the atmosphere to turn into an ice cap. When temperatures warm, the “ice” doesn’t melt, but vaporizes and returns to its gaseous state. Any ice that is actually the product of frozen water, would have disappeared long ago, because the vapor pressure of H20 is so low. When the temperatures rose to melting levels, that too would vaporize.
Had you planned a Martian excursion for May 17, 2002, at 62.7 degrees N latitude by 147.8 degrees E longitude, with an elevation of -3887 meters, it would have been a balmy -102.1C (-151.8F) in early Spring.
Besides the cold, Man would be subjected to levels of ionizing radiation that are only slightly lower than those of space, or the Moon. In other words, you’d need a special space suit. But could a functional one be made?
First of all, it would need to protect the wearer from Mars’ low pressure, and ultra violet radiation. The only planetary landing suit manufactured so far, was the Apollo Lunar EVA suit, weighing in at 100kg (220lbs.). The Moon’s gravitational force is only 16% of Earth’s, which reduced the load to 16kg or 35lbs. Still, it was awkward to wear and move in. Mars’ gravitational force is 40% of Earth’s, making that same suit 40 kg, or 88lbs. Given its unwieldy nature on the Moon, and with no experience of what they might encounter on Mars, the wearer might be able to admire the scenery, but that would be about it. By comparison, the current Shuttle EVA suite weighs in at 130kg (286lbs.) with all its pieces and accessories. In 1981, 43 of the original suits and 13 life support systems cost $107 million. You could save a few pounds (and dollars) by removing the liquid cooling system, but it would still not allow for any functional mobility.
Are we then limited to life on Earth?
In 1999, Dr. Chris McKay, the NASA researcher who first discovered what appear to be elementary bacterial fossils in a Martian meteorite, addressed a conference in Toronto, Canada, on bringing life to Mars. He first covered its evolution, including the past existence of large bodies of water, which studies of Earth’s own evolution suggested would contain life, since it developed so soon after creation on our own planet. Even if Mars was now lifeless, it had only been dead 3 billion years. Was it possible to CPR Mars?
Since Earth in its pre-Cambrian period had an atmosphere much heavier than today’s, being very largely carbon dioxide, it was un-breathable for humans. Man is helping return it to that state, by increasing the levels of CO2. This pre-Cambrian atmosphere was likely on a par with Mars original atmosphere. Bringing back this balance of elements, would be good for plant and animal life, but not humans. We would need high enough levels of nitrogen to provide a buffer gas, keeping the CO2 level low, while maintaining a level of oxygen to make breathing possible. McKay hypothesized that bringing the Martian atmosphere back to what it was in the beginning, was technologically possible, and would make possible, the support of any original life forms. Making that atmosphere habitable by humans, poses the real problem. It becomes a question of two different “worlds”.
Moving the nitrogen mass from Earth, needed to revitalize Mars, is impossible. McKay calculated it at a million times a million space shuttle launches. Calculating instead, the amounts of carbon, nitrogen and water needed to create a biosphere, he then went on to suggest ways of finding those on Mars itself.
The present atmosphere has nowhere near the levels needed. It is also too thin to support a biosphere. But current theories propose that these elements all exist in the crust and polar ice caps, water trapped as ice, nitrogen as nitrates and carbon as carbonates. Release these elements and you can start restoring an atmosphere that could support life. But first you have to get them out of the ground and ice. That means warming the planet.
McKay discussed in detail, the various gases in the Earth’s atmosphere that cause warming, including ones like CF4, carbon fluoride. Mars is known to have sulfur, chlorine and fluorine. By combining the right molecules, and making sure the resultant gases are good greenhouse absorbers with long lifetimes (in the hundreds of years), the temperature of the planet would go up enough to start melting the polar ice cap, and the ice in the crust, releasing the necessary elements. With an atmosphere thick in carbon dioxide, the planet would stay warm. But Man couldn’t breathe. Reduce the production/recovery of CO2, and the planet would cool, since the oxygen atmosphere would be unable to hold the heat from the distant sun.
His suggestions for the technical rebirth of Mars are based on scientific reasoning, although they stretch the human imagination. But then, Man has been stretching the envelope of life outside our own planet, for a long time. Some day, it may stretch to Mars.