Human Exploration of Mars Design Reference Architecture 5.0

[Robotbeat]

1) perchlorate hazard is vastly overstated.
2) space is absolutely not the only place that has needed to have airtight seals in the presence of dust or other debris.
3) it is actually okay to clean stuff off before going through an airlock. You don’t HAVE to expose the airlock itself to massive amounts of dust. A mud room to brush off dust is already part of the design of Starship HLS.

I’m a little disappointed in some of the seeming inability to think of fairly practical solutions to dust and airtight seals. This is something that has been solved to various degrees by makers of wooden barrels since ancient times and watertight ships’ doors since the 1800s (and pressurized aviation, etc, yeah, even in deserts where dust might exist).

[lamontagne]

1) perchlorate hazard is vastly overstated.
2) space is absolutely not the only place that has needed to have airtight seals in the presence of dust or other debris.
3) it is actually okay to clean stuff off before going through an airlock. You don’t HAVE to expose the airlock itself to massive amounts of dust. A mud room to brush off dust is already part of the design of Starship HLS.

I’m a little disappointed in some of the seeming inability to think of fairly practical solutions to dust and airtight seals. This is something that has been solved to various degrees by makers of wooden barrels since ancient times and watertight ships’ doors since the 1800s (and pressurized aviation, etc, yeah, even in deserts where dust might exist).

Absolutely.  Almost all NASA airlck designs I've seen just use the Mud room paradigm, or the two stage airlock, to control dust.  I like the aircraft example as well.  It's not an airlock just because there are not two doors in sequence and no pump down sequence, but it's a great start for one.

[Eric Hedman]

Has anyone considered the possibility of disposable coveralls over space suits to keep them clean from dust in the first space.  3M makes protective Tyvek bunny suits to cover workers going into messy environments.  If you had a spacesuit partially or fully covered and you just tear that covering off before you go in, couldn't that mitigate the majority of the dist and dirt?

[BN]

Has anyone considered the possibility of disposable coveralls over space suits to keep them clean from dust in the first space.  3M makes protective Tyvek bunny suits to cover workers going into messy environments.  If you had a spacesuit partially or fully covered and you just tear that covering off before you go in, couldn't that mitigate the majority of the dist and dirt?

this could help if done in the mud room, and those can likely be easier to clean than a fully dusty suit.

is tyvek the best material for this? it does seem to be light, tear-resistant and slippery..


if this becomes a thing, expect some very wrinkly looking astronauts

[Twark_Main]

Has anyone considered the possibility of disposable coveralls over space suits to keep them clean from dust in the first space.  3M makes protective Tyvek bunny suits to cover workers going into messy environments.  If you had a spacesuit partially or fully covered and you just tear that covering off before you go in, couldn't that mitigate the majority of the dist and dirt?

this could help if done in the mud room, and those can likely be easier to clean than a fully dusty suit.

is tyvek the best material for this? it does seem to be light, tear-resistant and slippery..


if this becomes a thing, expect some very wrinkly looking astronauts

"Toughness and flexibility are retained down to the glass transition temperature of HDPE (-100 °F [-73 °C])."

https://www.dupont.com/content/dam/dupont/amer/us/en/microsites/tyvek-design/images/documents/EN-NA-Tyvek(r)-Graphics-Printing&Technical-Guide-2018.pdf


" Tyvek® is not considered UV resistant and we do not recommend Tyvek® for applications where constant sun exposure is expected."

https://www.dupont.com/tyvekdesign/design-with-tyvek/dupont-tyvek-faq.html


When I've talked about "Tyvek" anti-dust suits in the past I just use the name as a stand-in for some suitable analogous space-rated material.

Is flashspun Kapton a thing?? 

[Robotbeat]

Nomex would work.

[lamontagne]

Nomex would work.

Can we make tires out of Nomex?  Or flexible membranes for the airlocks? Or as a fibre and we would need a filer anyway, and that would break  down in the cold?
Did the Lunar rover need steel wheel due to the cold on the Moon, or the cold transportation temperatures?  How much heating would allow a tire to remain flexible, therfore allowing flexible tires on the Moon and Mars, rather than the rather akward steel mesh designs?

[Eric Hedman]

Tyvek breaks down under typical UV light for outdoor applications on Earth if coated properly in 4 to 6 months of continuous exposure.  Does anyone know how UV intensity on the surface of Mars compares with Earth?  It would be interesting to see what its life would be given how often astronauts would be going out on the surface.  Tyvek is also extremely light in the range of 1 to 3 ounces per square meter depending upon thickness.  So even if disposable, it might not be too big a deal if astronauts could get 20 r 30 uses out of each one.

[BN]

Tyvek breaks down under typical UV light for outdoor applications on Earth if coated properly in 4 to 6 months of continuous exposure.  Does anyone know how UV intensity on the surface of Mars compares with Earth?  It would be interesting to see what its life would be given how often astronauts would be going out on the surface.  Tyvek is also extremely light in the range of 1 to 3 ounces per square meter depending upon thickness.  So even if disposable, it might not be too big a deal if astronauts could get 20 r 30 uses out of each one.

uv exposure is much higher on mars. it's likely to be an issue over time for a range of equipment. don't expect any snazzy paint jobs to hold up on mars.

Nomex would work.

Can we make tires out of Nomex?  Or flexible membranes for the airlocks? Or as a fibre and we would need a filer anyway, and that would break  down in the cold?
Did the Lunar rover need steel wheel due to the cold on the Moon, or the cold transportation temperatures?  How much heating would allow a tire to remain flexible, therfore allowing flexible tires on the Moon and Mars, rather than the rather akward steel mesh designs?

UV would be an issue for rubber tires and for nomex. nomex is more of a fabric than a structural material anyway. stainless steel mesh is probably the best option, although even those would require somewhat frequent replacement. (carry a spare) no need to reinvent the wheel again.

[DanClemmensen]

UV would be an issue for rubber tires and for nomex. nomex is more of a fabric than a structural material anyway. stainless steel mesh is probably the best option, although even those would require somewhat frequent replacement. (carry a spare) no need to reinvent the wheel again.

Nomex and Kevlar are in the same chemical family (aramids) and synthesizing them on Mars will be approximately the same difficulty. They are both sensitive to UV and need to be protected, usually by coating. Nomex and Kevlar are also sensitive to abrasion. Kevlar is stronger and more flexible than steel, which is why it replaced steel in radial tires.

[Robotbeat]

Yeah, UV coatings are feasible.