Comments on: Building a Moon Base: Part 3 – Structural Design

By: Marcos Passarello

Marcos Passarello — Sun, 14 Sep 2008 22:32:51 +0000

I see the diagrams of how to obtain He3 from the moon studying the papers of
University of Wisconsin.The design of mining machine to do this process
that go to the moon, extract He3,
come back to earth and in the middle of the way process the he3.
The methodologyâ€ BIAâ€, a matrix of all problems that the machine
could have in the way to the moon and in the way to earth.
The Impact found simple problems that could have the machine in the way
To the moon, and criticals problems, always is high. The times, for develop
the mining machine. The last matter will be work in Bio-fuels-Diesel,
it could be good for the future analyses of how to process He3 fuels.
I work and develop since years a methodology of Risk Space Management
using standards 4360 AUS-NZ ,NIST -800-30 and in the end i am working
with ISO 31000, and 31010.

By: T. Ziegler

T. Ziegler — Wed, 03 Sep 2008 04:09:58 +0000

Is it possible to make a tunnel borer that can be reassembled on the moon or mars and use this to enlarge or/and straighten lava tubes to emplace inflatable habitats? What else should be looked into?

By: T. Ziegler

T. Ziegler — Wed, 03 Sep 2008 04:01:54 +0000

Those of you who are old hats at this may have seen the website from Caterpillar(R). Their site has a video of the tractor they’re developing for NASA. It combines a bulldozer/skiploder as well as a module transport. I would suggest you watch the video if you have not already seen it.

By: Mr.S.Muthusamy

Mr.S.Muthusamy — Mon, 24 Mar 2008 21:09:45 +0000

On a lighter side of things, how wouldthe first human (beings)colonists will get along with each other?

By: Building a Base on the Moon at AntiTerra

Building a Base on the Moon at AntiTerra — Sun, 23 Mar 2008 15:32:38 +0000

[...] associated with such an endeavour, we have looked at the structures available to us, we have even detailed a particular hangar-like structure that might use locally mined materials. Now, we look into the possible infrastructure elements that [...]

By: F. Ruess

F. Ruess — Fri, 29 Feb 2008 15:12:51 +0000

Nice to see that extracts of my work with Benaroya are published here!

Only some quick thoughts on Mr McClatchie’s comments:

Of course the ideal shape in terms of building a pressure vessel from a stress point of view would be a sphere or a tube with spherical ends.
BUT, spheres and cylinder tend to roll! Astronauts need a flat floor (we’re not at zero g like Bigelow in Earth orbit).
The presented structure tries to deal with these and many other issues. It has structural hinges at the intersection of arch and flat floor, so there is no issue with stress concentration at the corners.

So many people talk about compensating dead loads on the structure with internal pressure. From my point of view there are at least 3 main load combinations one has to consider and the structure has to resist all of them:
1. Pressurized with no dead load in place (just before the regolith cover is put in place)
2. Regolith cover + Internal pressure (main operating condition and only here you have a balancing effect).
3. Catastrophic decompression with cover in place. I don’t think we should completely rule that scenario out. The structure should at least work long enough for the astronauts to escape into the next airlock.

The presented design is by far the only or the best solution. I don’t think such a solution even exists. But there are very many boundary conditions (many, many more than I mentioned here) and an adequate design has to consider all of them.

Best regards,
F. Ruess

By: Iain McClatchie

Iain McClatchie — Thu, 28 Feb 2008 06:46:57 +0000

Your arch has a flat floor, so it has corners, which is terrible for a pressure vessel.

You probably want a cylinder, with spherical ends, just like Bigelow’s inflatables. Then, you want to bury this thing, probably by putting it into a preexisting ditch, tethering it into place, and then detonating a series of small explosives to slump the sides onto the module, a little bit at a time. You do this with a bunch of modules and then find out which ones survived.

One of the interesting things about 1/6 gravity is that 1 atm of air can support 21 meters (!) of 3 g/cc overburden. There is a lot of margin between the amount of material required for adequate shielding and the maximum you can dump on the structure without crushing it.

Also, 1 atm of air is not much mass, about 1 kg/m^3. So, if you want 120 m^3 per person, you need just 120 kg per person for the air necessary to support the structure. The carbon fiber necessary to contain that might weigh 30 kg. So, the balloon structure isn’t the difficult part here. The assembly will be difficult.

Finally, your pressure vessel will develop leaks, and these will have to be patched from the inside. You need a mechanism to find the leaks, probably a smoke generator.

By: Links for 27-02-2008 | Velcro City Tourist Board

Links for 27-02-2008 | Velcro City Tourist Board — Wed, 27 Feb 2008 03:21:48 +0000

[...] – Building a Base on the Moon: Part 3 – Structural Design “To achieve inexpensive construction, as much local material must be used as possible. The [...]

By: Darnell Clayton

Darnell Clayton — Tue, 26 Feb 2008 02:37:54 +0000

Great article! Although I figured we would eventually have to use lunar soil in some “form or fashion,” I never realized how tough the stuff would be once melted.

The only problem that I see is what do you do if a hole is punctured through one of these slabs? But I guess that is where Bigelow’s inflatable technology (lining the walls) could come in.

By: “Building a Base on the Moon: Part 3 - Structural Design” - Out of the Cradle

Mon, 25 Feb 2008 01:38:45 +0000

[...] O’Neill, Ian “Building a Base on the Moon: Part 3 – Structural Design” Universe Today 02/20/2008 On-Line Text [...]