Re: Could the future spaceship be shielded from Ultrahigh energy cosmic rays?

Hello Yevgeniy,

Halfway through his answer, Ben writes on the damage caused by UHECRs here:

http://www.madsci.org/posts/archives/2005-04/1112438597.As.r.html

His suggestion, that no shielding might be better than some shielding is a good one, as it reduces the risks of spallation - a shower of dangerous secondary and subsequent particles - caused by a UHECR hitting the atoms within a dense shield.

However, it must be said that it is theoretically possible to provide enough shielding to protect a ship from all cosmic rays, providing we don't mind covering our ship with many metres of ray-absorbing materials. Ben suggests ten metres of rock is enough to stop a 200GeV proton.

Let's suppose that that's enough: every square metre of the surface of our ship would therefore need about 25 tonnes of shielding. In real terms this is not practical - an Apollo-type capsule, with a surface area of approximately 40 square metres, would need 1000 tonnes of shielding for its five-tonne mass.

I hope this helps,

Andy Goddard