Storm deflector: The Earth's magnetic shield naturally deflects solar radiation from the Sun (coming from the left of image). Now experts think the same principle could be used to protect spaceships too.
Credit: NASA
PARIS: Scientists believe they have found a way of shielding astronauts from a dangerous source of space radiation, thus lifting a major doubt clouding the dream to send humans to Mars.
Their breakthrough is reported this week in the journal Plasma Physics and Controlled Fusion – it takes forward ideas born in the golden age of science fiction, including a proton shield used in the TV show Star Trek, say the researchers.
Solar storms
Space weather is one of the greatest challenges facing a manned mission to the Red Planet. Even the shortest round trip (the distance varies between 55 million and more than 400 million kilometres) would take at least 18 months.
During this time, the crew would be exposed to sub-atomic particles that whizz through space, capable of slicing through DNA like a hot knife through butter, and boosting the risk of cancer and other disorders.
The peril has been known for nearly half a century, but has seemed insoluble 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 mind-spinning.
Another idea, born in the 1960s, would be to swathe a spaceship with a replica of Earth's own magnetic field. Our weak two-pole field deflects incoming cosmic rays, protecting life on Earth as well as astronauts in low Earth orbit.
Fresh take on an old idea
According to these 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.
Now, however, British and Portuguese scientists have taken a fresh look at the old concept and say the magnetic field does not, in fact, have to be huge – a "bubble" just 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," said Bob Bingham of the Rutherford Appleton Laboratory near Oxford in the United Kingdom.
"In 2001, a NASA study found
"In 2001, a NASA study found that at least 39 former astronauts suffered cataracts after flying in space, 36 of whom had taken part in missions beyond Earth's orbit."
Only crews of Apollo 8,10-17 left LEO, therefore 9*3 =27 (!)
astronauts had taken part in missions beyond Earth's orbit.
What about ones who have gone to Hubble?
What about ones who have gone to Hubble? Isn't that outside of low earth orbit? Just a guess...