British scientists are planning to see whether a Star Trek-style deflector shield could be built to protect astronauts from radiation. They argue that magnetic shields could be deployed around spacecraft and on the surfaces of planets to deflect harmful energetic particles. Scientists hope to mimic the magnetic field which protects the Earth. There are a variety of risks facing future space explorers, not least of which is the cancer-causing radiation from cosmic rays and solar flares that astronauts will encounter when they venture beyond the Earth's protective magnetic envelope, or magnetosphere. To create the deflector shield around a spacecraft or on the surface of a planet or moon, scientists need to generate a magnetic field and then fill it with ionised gas called plasma. The plasma would held in place by a stable magnetic field (without the magnetic field, the plasma would simply drift away). This shield could be deployed around a spacecraft or around astronauts on the surface of a planetary body such as the Moon. As energetic particles interact with the plasma, energy is sapped away from them and they slow down.
submitted by Shaun A. Saunders
submitted by Shaun A. Saunders
4 comments:
Considered from a perspective of space medicine, shielding from radiation is extremely important. Even astronauts working below the highly energetic van allen belts (i.e., on the shuttle) have reported flashes on their retinas when their eyes are closed.
But, an even greater challenge for any extended period in space is that posed by the effects of weightlessness in freefall confditions. This affects several systems in the human body:
* Fluid shifts within the body and loss of body plasma volume
* Loss of cardiovascular conditioning, bone mass, and calcium
*‘Space motion sickness’ and learning how to orient oneself and manoeuvre whilst weightless
*Disruption of visual cues
It is the 2nd category that is currently a 'deal breaker' and would effectively prohibit a trip to mars limited by curent enginmeering technology & space medicine.
That has been my contention for some time. Yes the radiation hazards are real but the worst impact to health is the long duration of weightlessness. What is truly needed is a .25g spin like on the Nostromo
In hindsight, I should have added that on a trip of short duration - such as to the moon - then radiation is the prime 'deal breaker'. Current space hardware does not have sufficient shielding, and even a moon base would require metres and metres of moon 'soil' to serve as effective shielding from solar flares and 'background' or usual solar radiation.
see, that lends itself to the question which is "what exactly is the plan for shielding in the much vaunted "permanent" shelters to be erected at the planed 2020 Moon bases?"
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