Dec 20, 16 21:40 UTC

Radiations  

Hello and welcome to the Space Health Hazards Forum!

The topic discussed here is all about Radiations It may involve but is not limited to Solar wind and Solar Particles Events Galactic and Cosmic high-energy Radiations Stochastic effect DNA damage effects Cancer Risk Immune, medication, nutritional status Genetic susceptibility Countermeasures Van Allen Belt LEO vs Outerspace

Let's have constructive and discerning exchanges together along with fun and friendlyness!

Jan 11, 17 17:01 UTC

Radiation can be a source of problems and a potential use. We could use solar radiation for power and for plants, but we also have to be able to detect flare activity well enough in advance to be able to protect all citizens (if they're not intrinsically protected already).

Jan 20, 17 04:55 UTC

I found an interesting article on the impact of radiation on astronauts' central nervous system: https://www.nasa.gov/mission_pages/station/research/experiments/137.html

Either we'll have to find a material capable of blocking radiation from reaching our citizens or be prepared for a very large number of cancer patients as our space based population ages.

Feb 3, 17 13:37 UTC

Hello, Asgardians...

FOR SURE, radiation is a subject that worries me a lot.

Greetings,

Leonardo.

Mar 21, 01 / Mar 18, 17 18:34 UTC

I can reduce the worry. The problem is "easy" to deal with.

First, a little about radiation. For a gross over-simplification think of a pool table setup to go and all the balls neatly in a triangle ready to break - this represents the contrsuct of an atom. Protons, neutrons and eletrons in a tidy little package. Should a stray particle of great speed impact this tidy little package - illustrated in this example by the white ball colliding the triangle on a break - it de-stablises the contents causing high speed particles to release.

The three major types of radiaiton - Alpha, Beta, and Gamma - are commonly ordered by "penetration depth" - long story short, density matters. The more dense an atom is, the more resistence it will pose to the high speed particles. Alpha is moving at the greatest speed, but has the least penetration depth - a few CM of air or a thick sheet of card can provide sufficient shielding. Your skin should be thick enough to stop it(although, it will absorb the damages and likely lead to things like skin cancer) and should require direct contact for long times to cause harm - swallowing it or breathing in a small particle however is likely fatal as it'll allow it to damage something important. Beta has a little more depth penetration going some distance in air a sheet of aluminium foil should be thick enough to absorb it. Gamma going many miles and taking a few inches of lead(denser than 80% of the periodic) to absorb.

Hydrogen, being atomically dense, is an excellent "barrier" - but has several drawbacks like being explosive and difficult to keep aligned in a useful pattern unless under pressure - and historically hydrogen and pressure don't tend to be a good mix. Water contains lots of hydrogen, and is dense as a substance whilst being significantly less volitile - however exposure will decay this to deutrium and reduce the supply of usable water which on the scale of it possibly isn't the most sensible resource to squander. To those thinking of just wrapping up in foil attention should be drawn to "secondary emittence" - to consider the pool table analogy, say the triangle is an aluminium atom... As the white ball(this time representing "cosmic rays") hits it and causes emittence, these would be recorded as X-rays. For something presenting minimal secondary emittences Iron appears to be quite good.

Iron is quite common, with most asteroids being quite heavy in their nickle and iron composition. To seriously entertain mass residence in the stars we'll need to be tapping resources in asteroids anyway - lifting the required mass is unfeasible as this would take thousands of years just to begin assembling pieces, at one launch per day using NASA's new SLS system comming online soon. Taking it from up there using exponentially expanding methods is the only way to get at such in a reasonably timeframe(and we're still talking decades) so naturally create megatonnes of nickle, and iron. Thusly, I personally would be creating an external barrier that clips to the external pressure hull of about five meters thick NiFe - This is largely overspec to requirements, with the nickle/iron composition providing for "sufficient" shielding from radiaiton at 1/5th of this thickness should any make it through the 7½CM of titanium it's skinned in.

I'd be comfortable sitting behind that, in a solar flare.

Aug 20, 01 / Sep 1, 17 20:19 UTC

NASA through the InnoCentive innovation platform hosted a challenge 3 years ago to try to solve the radiation issue.  There were 1142 active solvers of the problem but apparently no winning solutions as the challenge was later withdrawn (https://www.innocentive.com/ar/challenge/9933638).  I wonder if any of the proposed ideas involved the following.

Instead of an active shielding approach which would require massive amounts of energy, this is a passive shielding approach that also carries the side benefit of cleaning up all the space junk that exists around our planet.  Thick high density matter is well known for being able to stop cosmic rays and other energetic radiation sources in space so it makes sense we would want plenty of it to shield an Asgardian space station.  

The idea is to launch solar-powered autonomous "drones," each fitted with thrusters and an electromagnet.  The most promising pieces of space junk would be identified beforehand from those currently large enough to be tracked (https://www.nasa.gov/mission_pages/station/news/orbital_debris.html).  They would ideally be moving relatively slowly and in orbits that would come close to our space station at some point in the near future.  The drone would fly out to those pieces of space junk, using thrusters only for the purpose of changing trajectory.  Once it reached the junk it would use thrusters to match its speed and rotation so it can lock on with the electromagnet.  Then it would use thrusters again to nudge the piece of junk into an improved orbit that would have it coming close to the space station at some future point.  Then it would detach, recharge, and move on to the next promising piece of space junk.  Before the thruster fuel ran out it would make it back to the station for replenishment but otherwise these drones would be out doing their work.