A significant difficulty for manned missions outside of the Earth's magnetosphere, including Mars missions, asteroid exploration, and space-based mining and manufacturing, is the hazard of crew exposure to particulate radiation. With the recent resurgence of interest in manned Mars missions, crew radiation shielding has again become an active problem for investigation
One solution to the problem of shielding crew from particulate radiation in space is to use active electromagnetic shielding. Practical types of shield include the magnetic shield, in which a strong magnetic field diverts charged particles from the crew region, and the magnetic/electrostatic plasma shield, in which an electrostatic field shields the crew from positively charged particles, while a magnetic field confines electrons from the space plasma to provide charge neutrality. Advances in technology might include high temperature LENR based superconductivity in Bose Einstein condensation. Since the dangerous particles involved are charged, an alternative solution to the problem of shielding is the use of active electromagnetic shields. The simplest such device is the magnetic dipole shield. The magnetic field of the Earth is a good example of a magnetic shield, and is responsible for the relatively benign radiation environment on Earth. A magnetic shield makes use of the fact that a charge particle's trajectory in a magnetic field is curved. As a particle enters the region of high magnetic field, its trajectory will curve away from the region to be protected. In essence, the principle is exactly the reverse of that involved in a magnetic bottle; in this case the intent is to trap the particles outside the region of interest, instead of inside. The advantages of a magnetic shield to crew safety and health are obvious. A crew bound for Mars could be placed inside a liquid metal cooled hollow ellipsoid LENR Ni/H reaction chamber that provides propulsion for the Mars craft. The LENR reaction will divert the positive particle radiation and neutralize it in strong electrostatic electron concentrations. LENR could open the door to safe space transportation and habitation in a hazardous radiation environment.
