Mars Suit Outer Garment Fabric?

Hello Everyone,

I've been think about the requirements for the external garment worn
with a Mars Surface Spacesuit. Of course a TMG for Mars would be
greatly influenced by the type of suit under it whether it's a MCP or
soft or hard suit, still we should be able to narrow the types of
suitable fabrics for a TMG.

Typically Kevlar or Vectran are mentioned to me when a single material
is suggested and although they are in use in the space related
activities, Ortho-Fabric (Kevlar as rip-stop with Gor-Tex and Nomex)
of EMU and in the Pathfinder, MER and Beagle II Airbags (Vectran) they
quickly break down under UV.

Considering the possibilities of super peroxides, the abrasiveness of
the regolith, extreme cold environment, UV exposure and the long
duration these suits will be subjected to these conditions weaves of
several fibers maybe best. But these conditions will enviably expose
these weave's component fibers to things they don't tolerate well.
Anyway, for a variety of reasons I've been looking at current
sailcloths for the properties best suited for fabricating these TMGs
from. Some of my reasons being they spend lots of time looking for
performance characteristics similar to those need in a Mars Suit outer
garment. They require light weight, durable material with high
tenacity and flexure among other properties.

I think old standards of sailcloth making like Cotton Canvas, Nylon,
Dacron or Orlon might beat out such new comer as Spectra, Vectran and
Kevlar. Spectra is susceptible to creep, Vectran and Kevlar are
degrade exposed to UV and aren't as flexible.

So what material is your current favorite? What is your reasoning?

--Chris Vancil

beta cloth. It's well understood.

(MSu1049321) wrote in message ...
beta cloth. It's well understood.


Beta Cloth is made out of glass fibers. Some of the reasons that
Apollo era suits are now faling apart is Beta Cloth. It's primary
useful property is non-flammablity thus it's a good high temperature
flame barrier.

We need a fabric with many of the properties of heavy duty work jeans.
Kevlar and other High Modulus fabric are possible candidates. But
they need to be able to be stowed and folded and exposed to UV.

--Chris Vancil

Chris Vancil wrote:
(MSu1049321) wrote in message ...
beta cloth. It's well understood.


Beta Cloth is made out of glass fibers. Some of the reasons that
Apollo era suits are now faling apart is Beta Cloth. It's primary
useful property is non-flammablity thus it's a good high temperature
flame barrier.

We need a fabric with many of the properties of heavy duty work jeans.
Kevlar and other High Modulus fabric are possible candidates. But
they need to be able to be stowed and folded and exposed to UV.

Do 'we' have a good handle on how mars dust will behave?

Lunar dust is (IIRC) horribly abrasive, and gets in between woven
fabric fibers and starts to erode them, in addition to making sealing
difficult.

Is martian dust as bad, or does the presence of atmosphere and erosion
make it a bit less sharp?

--
http://inquisitor.i.am/ | | Ian Stirling.
---------------------------+-------------------------+--------------------------
All I want is a warm bed, a kind word and unlimited power -- Ashleigh Brilliant.

Ian Stirling wrote in message ...
Chris Vancil wrote:
(MSu1049321) wrote in message ...
beta cloth. It's well understood.


Beta Cloth is made out of glass fibers. Some of the reasons that
Apollo era suits are now faling apart is Beta Cloth. It's primary
useful property is non-flammablity thus it's a good high temperature
flame barrier.

We need a fabric with many of the properties of heavy duty work jeans.
Kevlar and other High Modulus fabric are possible candidates. But
they need to be able to be stowed and folded and exposed to UV.

Do 'we' have a good handle on how mars dust will behave?

Lunar dust is (IIRC) horribly abrasive, and gets in between woven
fabric fibers and starts to erode them, in addition to making sealing
difficult.

Is martian dust as bad, or does the presence of atmosphere and erosion
make it a bit less sharp?

The scientists that I've talked with on this subject are of two basic
opinions. One view is pretty much that the Moon's regolith is all we
know so we should assume it's like that. The other group see Mars
having erosion and say it is somewhere between Earth and the Moon.
The 64 million dollar question is where on a hypothetical erosion
graph does Mars regolith lay?

I will hazard a layman's unprofessional guess. It's at least as
eroded as ash from Mount St. Helens is now 23 years later.

There are ways to block the dust getting into the bearings of a
pressure suit, but more research needs to be done on this problem
before committing to a final choice of outer garment design. Still
picking fabrics that might be workable seem doable now.
--Chris Vancil

Duct tape.

In article ,
Ian Stirling wrote:

Henry Spencer wrote:
In article ,
Ian Stirling wrote:
Do 'we' have a good handle on how mars dust will behave?

Not a good one. Current guess is that it will be much like lunar dust,
but data is very limited.

Lunar dust is (IIRC) horribly abrasive, and gets in between woven
fabric fibers and starts to erode them, in addition to making sealing
difficult.

Correct. The Apollo suit joints were giving trouble after only three days
of exposure to it. The wear problems were reduced considerably by adding
expendable overgloves, but this wouldn't have sufficed forever.

Was it especially irritating to skin, or did it not often get that far?

It did work into the skin, and there was concern about irritation and
worse over longer time periods. I was told by a few astronauts they just
had to let their skin *grow* it out.

All in all, for stays longer than a month or so, I would demand
*someplace* to get in out of the dust and get clean. Our team's choice
for this, as our papers point out, is a lavatube cave as a base site,
far enough into the tube from the cave entrance that the base isn't
contaminated with lunar surface dust.

Regards,

Tom Billings

--
Oregon L-5 Society

http://www.oregonl5.org/

In article ,
Ian Stirling wrote:
Correct. The Apollo suit joints were giving trouble after only three days
of exposure to it. The wear problems were reduced considerably by adding
expendable overgloves, but this wouldn't have sufficed forever.

Was it especially irritating to skin, or did it not often get that far?

It got everywhere within the LM -- the LM crew were notorious for looking
like coal miners by the time surface activities were over -- but I don't
recall any mention of skin irritation.

There has been some speculation that Mars dust might be chemically active,
which would require more stringent measures to control it. (On the other
hand, there were speculations like that about Moon dust too, which proved
totally unfounded.)
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

Ian Stirling wrote in message ...
Chris Vancil wrote:
(MSu1049321) wrote in message ...
beta cloth. It's well understood.


Beta Cloth is made out of glass fibers. Some of the reasons that
Apollo era suits are now faling apart is Beta Cloth. It's primary
useful property is non-flammablity thus it's a good high temperature
flame barrier.

We need a fabric with many of the properties of heavy duty work jeans.
Kevlar and other High Modulus fabric are possible candidates. But
they need to be able to be stowed and folded and exposed to UV.

Do 'we' have a good handle on how mars dust will behave?

Lunar dust is (IIRC) horribly abrasive, and gets in between woven
fabric fibers and starts to erode them, in addition to making sealing
difficult.

Is martian dust as bad, or does the presence of atmosphere and erosion
make it a bit less sharp?

Or it is _worse_ than lunar dust? Erosion may make finer particles,
dry conditions keep them from re-bonding to soil, wind can drive them
deeper into fabric/joints, and they may be more chemically active. Do
any Mars probes (current or proposed) include means to collect data on
dust (size,amount, composition)?

(Bill Bogen) wrote in message . com...
Ian Stirling wrote in message ...
Chris Vancil wrote:
(MSu1049321) wrote in message ...
beta cloth. It's well understood.


Beta Cloth is made out of glass fibers. Some of the reasons that
Apollo era suits are now faling apart is Beta Cloth. It's primary
useful property is non-flammablity thus it's a good high temperature
flame barrier.

We need a fabric with many of the properties of heavy duty work jeans.
Kevlar and other High Modulus fabric are possible candidates. But
they need to be able to be stowed and folded and exposed to UV.

Do 'we' have a good handle on how mars dust will behave?

Lunar dust is (IIRC) horribly abrasive, and gets in between woven
fabric fibers and starts to erode them, in addition to making sealing
difficult.

Is martian dust as bad, or does the presence of atmosphere and erosion
make it a bit less sharp?

Or it is _worse_ than lunar dust? Erosion may make finer particles,
dry conditions keep them from re-bonding to soil, wind can drive them
deeper into fabric/joints, and they may be more chemically active. Do
any Mars probes (current or proposed) include means to collect data on
dust (size,amount, composition)?

Of coarse water wind erosion makes finer smoother particles. They are
very probably chemically active with peroxides. You want a very fine
weave or a possibly a solid barrier. I was hoping not to get into the
problems with the pressure suit itself by only focusing on the outer
garment.

Future testing of Mars' environment with a focus on manned visits:
MECA (Mars Environmental Compatibility Assessment)
http://mars.jpl.nasa.gov/2001/lander/meca/

--Chris Vancil