How do astronauts suits protect them from Solar Radiation?

[Tokage]

I assume, that when in orbit, astronauts are still somewhat protected by the Earths magnetic field? However, what about when they're on the moon? Does the Earths magnetic field extend that far? If not, how do they protect their bodies from harmful radiation?

 

[Drakkith]

I don't know the particulars, but maybe this will help.
http://en.wikipedia.org/wiki/Space_suit

The various liners and layers of the space suit incorporate materials designed to absorb or block radiation and other hazards in space.

 

[Nik_2213]

Put bluntly, space-suits offer little protection from cosmic rays or a solar storm. Spacecraft such as ISS station must be designed with a 'storm cellar', an arrangement of equipment that will double as shielding when faced 'up-sun'...

IIRC, a massive solar flare occurred between the Apollo #16 & #17 missions which could have given an exposed crew a near-fatal radiation dose. It would certainly have made them very ill, perhaps incapable of flying the return leg of the mission...

This is why, although many artists' impressions of a moon-base show a cluster of pressurised modules, the real thing must add a thick topping of moon-dirt or have a 'storm-cellar' tunnelled several feet underground...

Similar problems apply to manned Mars missions, IIRC, as Mars does not have enough atmosphere or magnetic field to shield the surface...

 

[FtlIsAwesome]

Similar problems apply to manned Mars missions, IIRC, as Mars does not have enough atmosphere or magnetic field to shield the surface...

But Mars is farther from the Sun, so it would receive less solar radiation--how much less, exactly?

 

[Andy Resnick]

According to Buckey's "Space Physiology", the relevant dose rates are:

8d Shuttle flight 0.0053 Sv
5mth on Mir 0.16 Sv
Dose on Mir from October 1989 solar event 0.15 Sv
Trip to Moon 0.011 Sv
Trip to Mars (flight) 0.5 Sv/yr
Surface of Mars 0.12 Sv/yr

For comparison, a chest x-ray delivers 0.0001 Sv, and the galactic cosmic radiation background (no shielding, solar minimum) is 0.5 Sv/yr

As mentioned, shielding is required for spaceflight- the suit will protect against alpha radiation, but little else. Spacecraft can also protect against beta radiation. In the end, it's the gamma radiation that causes problems.