Dr. Dennis Bushnell, Chief Scientist at NASA Langley Research Center, joins us to discuss the scientific and technical challenges faced by NASA in planning future manned missions to Mars and beyond. He describes the National Space Exploration Vision, which cites human expeditions to Mars, and indicates that cost and safety are the two major obstacles faced by NASA in realizing this vision.
According to Bushnell, hexavalent chromium in martian dust, interstellar radiation, and lengthy trips in a microgravity environment damage the immune system of astronauts and increase their risk for cancer, which is caused by both radiation and chromium VI. He indicates that the best probability for minimizing these risks comes from dust-filtration research currently being undertaken at NASA as well as in finding new methods of propulsion that should shorten trip times and therefore reduce radiation & microgravity exposure by astronauts.
Bushnell describes research into launch-assist technologies such as magnetic accelerators and the space elevator that may assist future spacecraft in reaching orbit with less fuel, and describes advanced propulsion technologies such as aneutronic fusion and antiproton drives that may provide higher specific impulse. By combining these technologies along with lean ground crews to reduce NASA’s “standing army”, Bushnell suggests that not only could the cost of space travel be cut substantially but safety could be improved as well.
In addition to aneutronic fusion research, Bushnell also describes recent interest by NASA in Low-Energy Nuclear Reactions (LENR), more commonly known as “Cold Fusion” as discovered by Pons and Fleischmann in 1989. According to Bushnell, experiments over the last 23 years have led to a substantial body of evidence that supports the existence of LENR effects, which he hopes may be harnessed to provide power for future spaceflight.
Bushnell also briefly describes robotic missions to Mars, and the idea of “Robots as Mankind’s Children” as proposed by Dr. Hans Morovec and popularized by Ray Kurzweil. According to Bushnell, the 21st century will be dominated by virtual telepresence, and advances in robotics may provide us with the ability to explore Mars remotely in a virtual environment so real that explorers wouldn’t be able to tell the difference. The only question remaining is whether robot exploration diminishes mankind’s achievement, which Bushnell doesn’t believe to be the case.