Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Thursday, December 14, 2006

The 2006 Solar Radiation Storm

The astronauts of the International Space Station slept in unusual quarters last night, taking shelter from a solar radiation storm. When I heard that, even though I have worked in space life sciences for most of my professional career, I had to ask myself the question, “What exactly does THAT mean?”

We all have these images of alarms sounding and space ships bucking and rocking around and sweaty astronauts clinging to equipment in fear as the raging radiation storms buffets the ship. But, alas, it is nothing like that. In fact, had our solar observatories and satellites not reported it, they would never have known there was a solar event in progress at all.

And what kind of shelter are they talking about? Is there a hardened radiation bunker onboard the space station that they seal themselves up in and wait out the storm? And how bad was it And how bad can it get? And what are the contingencies for the entire scale of possible solar storms that might impact the space station?

Those are all excellent questions that have been asked before, of course.

The space station does not have a hardened radiation bunker. But last night the shuttle crews were ordered to sleep in the space shuttle’s middeck and space station astronauts were ordered to sleep in the aft ends of the space station's U.S. Destiny laboratory and Russian-built Zvezda service module which have greater densities of materials between them and space.

What’s the concern? Flight surgeons worry most about high-energy solar protons, which can penetrate deep into the body. Severe exposure can cause radiation sickness, increased cancer risks or death. Greater shielding - or in this specific case - more equipment, machines and specifically placed geometries and craft orientation were all used together as a "substitute" for hardened shelter shielding.

Has there ever been a significant worry in spaceflight history? Yes - an Apollo crew that walked on the moon in 1972 narrowly missed a potentially lethal dose of radiation from a solar storm that struck soon after the crew left.

If you are interested in such scientific facts in an exciting fiction setting, try reading my book, Quantum Storms which covers the full range of what the sun may be capable of doing in its worst moods!

Finally, if you would like an exhaustingly detailed but very interesting web based mini-book published by the National Academy of Sciences on this very topic, click here.