Astronauts could one day be protected from harmful cosmic rays during a long haul spaceflight by a powerful magnetic bubble generated by their own craft.
A new project to investigate the possibility of fitting spacecraft with a “magnetosphere” of their own, underway at the Massachusetts Institute of Technology, US, recently received a cash boost from the NASA-funded Institute for Advanced Concepts.
This is a greater problem on the Moon and Mars and on a trip to Mars. In Earth's orbit the planet's magnetic field (a.k.a. magnetosphere which creates the Van Allen radiation belts of mostly proton particles captured around the Earth) provides some protection from cosmic and solar radiation. The atmosphere provides an even greater level of protection.
Humans can not live on the surface of the moon or Mars in structures that are only thick enough to contain atmosphere. A solar flare or burst in cosmic radiation would eventually kill humans unless a greater level of protection can be provided.
The amount of any radiation increase depends strongly on where one is located. If you are in a spacecraft outside the Earth's magnetic field, the radiation doses can be quite large (as much as tens of Gray—1 Gy = 100 rad), depending on how much spacecraft shielding there is around you. If you are in a spacecraft, such as the Space Shuttle or International Space Station, in Low-Earth Orbit, the doses are lower (up to tens of milligray)—specific values depending upon the altitude and inclination of the orbit and the amount of shielding provided by the spacecraft.
The creation of an artificial magnetic magnetic field powered by a mini-nuclear reactor or even by solar panels might allow humans to spend much longer periods of time on the surface of Earth's moon or Mars. Here is another reason to develop space nuclear reactors. More power is almost always useful.
|Share |||Randall Parker, 2004 November 21 08:59 PM Space Exploration|