The latest Carnival of Space is now available at the Mars Odyssey blog, where Nancy Houser has gathered space-themed materials from the past week, many of them dealing with the question of perchlorates on Mars and the implications of that possible discovery. I’ll send you straight to the Carnival for the perchlorate story, where many bloggers dissect it. My usual practice is to focus on Carnival items that connect to our theme here on Centauri Dreams — articles about deep space starting with the outer planets and moving to regions beyond. This week the entry that fits that bill is Brian Wang’s article in NextBigFuture on radiation shielding.
Although Brian couches this work in the context of solutions to radiation exposure following nuclear attacks, it’s also true that a drug that is 5000 times more effective at reducing the effects of radiation injury than the drugs we currently use has interesting space implications. The experimental drug, intriguingly named Nanovector Trojan Horses (NTH), is based on single-walled carbon nanotubes that are coated with antioxidant compounds commonly used as food preservatives. In this setting they seem to dampen the effects of serious radiation exposure.
The NTH work (led by James Tour at Rice University) raises the question of how useful radiation shielding becomes as we move out into the Solar System. It’s commonly assumed that a human presence on the large Jovian moons, for example, is all but ruled out by intense radiation there. But future breakthroughs in radiation shielding and treatment, perhaps one day leading to turbo-charged vaccines against radiation damage, could help change that picture and allow scientists to function in such settings. Boots on the ground in places like Europa may no longer be completely inconceivable, and given what we may find there or, perhaps, on Callisto or Ganymede, that could be useful news indeed.
Even if NTH vaccines do work out, are they a solution for long-term habitation in these places. It has always been my assumption that both the Jovian and Saturn large moons are effectively off limits to human habitation (even our robot probes have a hard time in these places), thus leaving only 3 large solar system bodies available for human habitation – Moon, Mars, and Triton.
All the more argument for Gerard O’neill.
Also, does anyone here know the latest info with regards to zero-g adaptation for Earth life? The latest paper I ran across suggests that long term exposure to slightly higher gravity (say 1.2-1.3 g or so) was actually better than 1 g, because it stimulated the self-repair mechanisms in biological systems.
Radiation hardening of humans with antioxidants has been known since the late 40’s, when simple experiments using Vitamins A and C were performed.
You can radiation harden yourself today. Much better anti-oxidants such as BHT and BHA (both used in Tour’s NTH compound) as well as CoQ-10 are available, with member discount, from the LEF at http://www.lef.org.
considering the time it takes for a nation to decide to visit the moon and mars, it will take even longer to commit to fly to Jupiter or Saturns moons. In my opinion the most interesting places in our solar system. Wouldn’t it make more sense to use the time to develop a radiation hardened human genome, with much better cell repair mechanisms?
And concerning habitation, there might be the odd asteroid inviting for longer sleepovers.
There are five/six main categories of radiation protection/technology that I can see that all seem to be improving.
1. The anti-radiation damage drugs of which the James Tour one is the highest potential. There are others.
2. Radiation immunity enhancement. Several gene therapy and drug treatments that could make what would have been 50% fatality down to 20% or less.
3. New physical materials. Like graphene and nanotubes with high hydrogen doping levels.
4. Electric, electro-static, magnetic shielding
5. Materials for converting radiation directly into electricity.
I think there is a possibility that metamaterials could guide certain wavelike radiation around objects. The metamaterials that they are trying to use to make objects invisible to light and sound.
Philip,
What you suggest is already be worked on as part of a more general effort to eliminate aging. I agree with you that this effort, as well as biotech research in general, is likely to be successful before we will settle the outer solar system, let alone undertake interstellar travel. There is reason why Keith Henson, the first president of L-5 Society, said in the late 80’s that all serious “spacers” are into life extension and cryonics.
Hi All
According to Bob Zubrin’s discussion in “Entering Space” an unprotected human on Ganymede would be subjected to about 8 rem/day on the surface, and 540 & 3600 rem/day on Europa and Io respectively. Thus the new drug might allow habitation on Europa – at least brief forays to the surface. Only a metre or so of ice would be enough to totally shield from radiation belt ions, and ~2 metres for cosmic rays. Ganymede and Callisto would be easy. But I do wonder about the damage wrought by cosmic rays. It’s rather more direct than the MeV protons in the radiation belts.
kurt9
I do not think rads are an issue for Saturn’s large moons. People, educate me if I’m wrong here.
kurt9,
I didn’t know it, but now I consider myself a serious spacer.
Thanks for the hint.
Philip,
No offense meant.
However, Keith Henson’s comments were spot on given that he made them at a cryonics conference in 1986 and that serious space colonization (where people like you and I live in space) is unlikely before, say, 2040. If one was 20 years old in 1986, the same person will be around 74 years old in 2040. Thus, without radical life extension, any person active in L-5 Society during its heyday will not be going into space, period.
Besides, I have always considered space colonization and radical life extension to be synergistic. The two naturally go together.
I’d guess the surface of Titan would be fairly well shielded from the radiation, no?
Not sure about how much shielding the magnetic field of Ganymede would provide though.
November 4, 2008
Ion Shield for Interplanetary Spaceships Now a Reality
Written by Ian O’Neill
Bubble chamber image of charged particles being deflected by a
magnetic field (CERN) British scientists invent “mini-magnetosphere”
to protect astronauts during solar storms.
Space travel during a solar storm just became a little less risky.
UK scientists working at Rutherford Appleton Laboratory near
Oxford and the universities of York and Strathclyde have tested
a “mini-magnetosphere” enveloping a model spacecraft in the lab.
It turns out that their prototype offers almost total protection against
high energy solar particles. By mimicking the natural protective
environment of the Earth, the researchers have scaled the protective magnetic bubble down into an energy efficient, yet powerful deflector
shield.
This astounding achievement is a big step toward protecting sensitive electronics and the delicate human body against the radioactive
effects of manned missions between the planets. It may sound like
science fiction, but future astronauts may well shout the order to
“RAISE SHIELDS!” if the Sun flares up during a 36 million mile
journey to Mars…
Full article here:
http://www.universetoday.com/2008/11/04/ion-shield-for-interplanetary-spaceships-now-a-reality/