I have been a science fiction fan since I was a teenager. I have always assumed that someday, the human race would explore the solar system. We have already walked on the moon and sent robot probes to the inner and outer planets. The planet Mars has held a fascination for the human race and, with the coming of the Twentieth Century, stories were written about the human exploration of Mars. As I write this blog post, we have a roving vehicle on Mars taking pictures and analyzing soil samples. There have been projects where volunteers lived for months inside an isolated environment to simulate a months’ long trip to Mars. In the past year, a group called for volunteers who are willing to take a one way trip to that planet and they got thousands of responses.
Unfortunately for those who dream of the human exploration of Mars, recent scientific findings suggest that the radiation in space would pose a major hazard to any human explorers who spend months of space travel to reach Mars. During its trip to Mars, the Curiosity Rover spacecraft measured the radiation it encountered and found that human travelers would be exposed to over three times the radiation from cosmic rays and energetic particles from the sun that astronauts now encounter in the International Space Station. With current technology, the minimum transit time for a one way trip to Mars would be about six months. There is a tradeoff between shielding materials that could protect against radiation and the fuel required to lift the shielding off the earth and propel it through space. It appears that current spacecraft designs would expose astronauts to sufficient radiation on a trip to Mars to significantly impact their health.
Fortunately for Mars exploration enthusiasts, NASA has been talking about the prospects for a rocket powered by nuclear fusion. Nuclear fusion has not yet reached the point where a fusion reactor will consistently produce more energy than it consumers. On the other hand, creating a nuclear fusion rocket engine should be much simpler than creating a fusion reactor for power generation. The rocket engine would just use the fusion reaction to produce a burst of energy for propulsion instead of having to sustain a fusion reaction for power generation. NASA is currently funding research into prototype fusion engines. One of these projects at the University of Washington calculates that a fusion engine could take a rocket to Mars in thirty days. This would reduce the radiation to a manageable level and also reduce the need for food and water for the passengers. Not only would such an engine bring Mars within reach but would also open up the whole solar system to human exploration and exploitation. For instance, a fusion powered ship would be able to reach Saturn in a couple of months.
One additional benefit of developing a fusion rocket engine might be to advance the general field of fusion research and bring us closer to a working fusion reactor for power generation. Nuclear fusion would be a way to help mitigate climate change without all the dangers and waste production of nuclear fission reactors.
Mars:
