Thursday, November 6, 2008
Scientists believe they have found a way of protecting astronauts from a dangerous source of space radiation, clearing one of the hurdles towards sending humans to Mars.
The device has been developed by British and Portuguese scientists and appears in the journal Plasma Physics and Controlled Fusion .
Radiation is one of the greatest challenges facing a mission to the red planet, planned by the United States and Europe in the first half of this century.
The shortest round trip would take at least 18 months, and during this time, the crew would be exposed to sub-atomic particles that whizz through space. These particles are capable of slicing through DNA and boosting the risk of cancer and other disorders.
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The peril has been known for nearly half a century, but has seemed difficult to solve because costs and technological difficulty.
Some experts have toyed with the idea of shielding the crew with lead or massive tanks of water, but the price of lifting this load into orbit from earth is high.
Another idea would be to swathe the spaceship with a replica of earth’s own magnetic field, deflecting incoming cosmic rays.
According to previous calculations, the spacecraft would have to generate a magnetic field hundreds of kilometres across.
But such equipment would be huge and drain the ship’s energy supply and its powerful field could well harm the crew.
British and Portuguese scientists have taken a fresh look at this old concept and say the magnetic field does not, in fact, have to be huge – just a ‘bubble’ a few hundred metres across would suffice.
“The idea is really like in Star Trek, when Scottie turns on a shield to protect the starship Enterprise from proton beams – it’s almost identical really,” says Bob Bingham of the Rutherford Appleton Laboratory in the UK.
Their research uses numerical simulations also used by experts in nuclear fusion, in which hot plasma is kept in place by a powerful magnetic field.
This technology provides an accurate picture of how individual particles behave when they collide with a two-pole magnetic field.
As a result, the researchers have been able to devise a smarter, miniaturised model of magnetic protection.
Full story here.