

'Shrapnel' risk to future Moon surface missions - Zenst
http://www.bbc.co.uk/news/science-environment-26637231

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brownbat
Along with the dust. That stuff is apparently nasty. It's glass shards melted
around iron blasted by UV rays. So it has ridiculous static cling and the
consistency of sandpaper. It levitates up to a kilometer above the surface
because of these properties. Dust got in everything, and was an eye and lung
irritant on the entire trip back for Apollo missions that included a moonwalk.
(If too much gets in the lungs, an astronaut can face iron toxicity.)

NASA research presentation, lists many of the problems:
[http://isru.msfc.nasa.gov/lib/Documents/BenefWksp2010/presen...](http://isru.msfc.nasa.gov/lib/Documents/BenefWksp2010/presentations/Street_Living_on_a_Dusty_Moon.pdf)

NASA labs are working on dust mitigation, it's probably not an insolvable
problem. And some NASA engineers claim you might be able to do cool things
with it, like melt it glass roads without additional construction materials.
But mitigating all the nasty is still a damn hard engineering problem.

~~~
andrewflnr
How does the dust levitate? I would think the moon itself needed to have an
electric field to make that work.

~~~
brownbat
Funny you should ask, we actually have a Lunar module studying this question
right now:

[http://en.wikipedia.org/wiki/Lunar_Atmosphere_and_Dust_Envir...](http://en.wikipedia.org/wiki/Lunar_Atmosphere_and_Dust_Environment_Explorer)

The NASA dust lab slides claimed it levitated right after noting that the dust
particles had "charges approaching 10^4" (no units or context provided). I
assumed that was related. In hindsight, maybe it isn't?

Apparently, and I'm just learning all this right now, some scientists argue
the dust is primarily ejected from the surface during meteor events.

The earliest observations of "levitating" dust were from astronauts who
noticed rays of light during/after the lunar sunset, suggesting the sunlight
was bouncing off of something in the lunar "atmosphere."

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Sanddancer
While it is indeed a risk, it's something NASA, and other agencies, have been
working and designing suits around for years. Micrometeorites and the like
about the size of the objects this article talks about are also prevalent in
low earth orbit where the ISS is, and we've not had anyone seriously injured
in that environment. In fact, one of the pages on NASA's educational site
talks about issues very similar to this [1]. Plus, every space mission has
gone with a pretty extensive medical kit [2], and suit repair kit [3], and I'm
certain that anyone going to the moon would receive training as to how to
clean and dress a wound should someone get peppered from meteorite shrapnel.

[1]
[http://quest.nasa.gov/space/teachers/suited/9d2micro.html](http://quest.nasa.gov/space/teachers/suited/9d2micro.html)

[2]
[http://history.nasa.gov/SP-4029/Apollo_18-42_Apollo_Medical_...](http://history.nasa.gov/SP-4029/Apollo_18-42_Apollo_Medical_Kits.htm)

[3]
[http://airandspace.si.edu/events/apollo11/objects/apolloarti...](http://airandspace.si.edu/events/apollo11/objects/apolloartifact.cfm?id=A19791764000)

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ams6110
This seems like a significant problem. One possible solution is to build any
future lunar bases underground. That would protect them from most "shrapnel"
but there's still the danger of a direct meteor strike, which are much more
common on the moon since there's no atmosphere to speak of. You'd have to go
pretty deep to be safe from those.

~~~
fragsworth
Far enough underground (a few meters) and I think the risk is acceptable. The
one in the article made an 18m-diameter crater, so maybe 5-9m deep, but this
kind of impact is relatively rare and very unlikely to be in the location of
the base.

It's the shrapnel we are worrying about most, not the direct impacts.

~~~
Zenst
I agree underground would be the way, just to curtail radiation, which for a
moon base, long-term would be a consideration.

~~~
hga
As long as you can see the sun, you need that. And it's got to be thick enough
to stop secondary particles, a really thin shield can be worse.

The Apollo missions were timed for the part of the sun's cycle where activity
was low, and I've read that their early termination was due in part to the
schedule slipping and the last few planned missions edging into the period
where the probability of a solar storm killing the astronauts became
uncomfortably high.

