I've been involved in Mars Exploration, directly and indirectly. As a member of a Project Team at the Jet Propulsion Laboratory in Pasadena, I sat in the Mission Manager's site as the countdown was proceeding for the launch of the Mars Observer spacecraft in Fall of 1992.
As the countdown was proceeding, and as we came down to zero seconds remaining, I had the sense of things not being real. I am one of the group referred to as "baby boomers", and had followed with an ever-increasing sense of wonder how we had progressed from "sputnik" and "pioneer", to Apollo Eleven's and follow-on successful missions to the moon.
Of course, the next step is certainly Mars. Everything that has gone before points us toward the "red planet". This year, as you scan the eastern sky over North America in the evening, you can see Mars almost beckoning to us.
The point that brings me crashing back to a more analytic frame of reference is the question that has been nagging me ever since. Suppose we are successful in marshaling a mission to Mars, and suppose further that we're successful in returning the explorers to Earth. What next?
What next? What would be the purpose in human exploration and possible exploitation of Mars? The dangers of getting there and back are very numerous. Not insurmountable. But very numerous. For one, the space travelers would be en-route for ten or eleven months, with no possibility of rescue should something go wrong with their equipment. They would be exposed to prolonged radiation doses which would potentially be extremely dangerous. They would finally arrive, plant the flag of our nation, and hopefully those of other nations, collect some samples, and take steps to return to Earth. Another long period of time would be required to return. Remember, Earth and Mars are in position for interplanetary trajectories which permit relatively short travel between them every two years. Would the explorers have to wait that long to begin their return journey? Where could we go from there? To other planets in our own solar system? The distances from our own star to planets orbiting other stars are vast to the extent that they must be described in terms of light years. Three hundred light years is, I believe, the closest candidate star with a potential solar system. Three hundred should be thought of in terms of the time it would take light to travel that far. One light year is about six trillion miles. Three hundred light years is six trillion miles multiplied by three hundred.
Robotic exploration of Mars has been successful. Viking, Sojourner, Spirit and Opportunity, Phoenix, and Athlete to come will give us as much information as we'll need to determine why Mars is a dead world. No lives need be put at risk. We can explore the universe from the comfort of home.