A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Space Science » Science
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Make vs. buy for a Martian colony



 
 
Thread Tools Display Modes
  #1  
Old August 27th 18, 08:46 PM posted to sci.space.science
Thomas Koenig
external usenet poster
 
Posts: 47
Default Make vs. buy for a Martian colony

Make vs. buy (where "buy" has a likely lead time of anywhere
between six months and more than two years) decisions are going
to be hard for any Martian colony that has not developed a full
industrial base comparable with what we have today on Earth.

Even something simple, like an oil-resistant nitrile rubber O-ring
gasket, would require a long chain of manufacturing, starting out
with Butadiene (which requires something like a steam cracker),
Propene and Ammonia for the monomers, plus emulsifiers for the
emulsion reaction and large amounts of water which would end
up polluted. Also, rubber manufacturing is quite a specialized
process.

This would only give you the base polymer. In any useful rubber
compound, you are likely to find 20 to 30 different chemicals, from
fillers (carbon black, silica, plasticizers), a rubber protection
system (UV, oxygen, radiation, Ozone, fatigue, ... protection),
processing aids (lubricants, tackifiers, dispersion agents,
peptizers, oil), vulcanizing agents such as sulfur or peroxides,
activators, accelerators, scorch retarders), and probably others
I have forgotten. Each of these has their own synthesis route
and supply chain.

And you will also need specialized catalysts for making many
of the materials that will have to go into that simple gasket...

All of this for a part that will cost a few cents here and now.

So, it is likely that drastic simplification will be needed
to build up an industry on Mars, both in material selection
(don't try to use the best materials available on Earth
for that spacesuit) and in processes (accept inefficiency
that would bankrupt any company on Earth today).

And don't count on a Mars colony becoming independent from
Earth supplies any time soon.

What work has been done in what a Martian colony would be able
to produce for itself, work that addresses the complexity that
I have only given a very small part of?

Ads
  #2  
Old August 28th 18, 01:41 AM posted to sci.space.science
Alain Fournier[_3_]
external usenet poster
 
Posts: 356
Default Make vs. buy for a Martian colony

On Aug/27/2018 at 3:46 PM, Thomas Koenig wrote :
Make vs. buy (where "buy" has a likely lead time of anywhere
between six months and more than two years) decisions are going
to be hard for any Martian colony that has not developed a full
industrial base comparable with what we have today on Earth.

Even something simple, like an oil-resistant nitrile rubber O-ring
gasket, would require a long chain of manufacturing, starting out
with Butadiene (which requires something like a steam cracker),
Propene and Ammonia for the monomers, plus emulsifiers for the
emulsion reaction and large amounts of water which would end
up polluted. Also, rubber manufacturing is quite a specialized
process.

This would only give you the base polymer. In any useful rubber
compound, you are likely to find 20 to 30 different chemicals, from
fillers (carbon black, silica, plasticizers), a rubber protection
system (UV, oxygen, radiation, Ozone, fatigue, ... protection),
processing aids (lubricants, tackifiers, dispersion agents,
peptizers, oil), vulcanizing agents such as sulfur or peroxides,
activators, accelerators, scorch retarders), and probably others
I have forgotten. Each of these has their own synthesis route
and supply chain.

And you will also need specialized catalysts for making many
of the materials that will have to go into that simple gasket...

All of this for a part that will cost a few cents here and now.

So, it is likely that drastic simplification will be needed
to build up an industry on Mars, both in material selection
(don't try to use the best materials available on Earth
for that spacesuit) and in processes (accept inefficiency
that would bankrupt any company on Earth today).

And don't count on a Mars colony becoming independent from
Earth supplies any time soon.

What work has been done in what a Martian colony would be able
to produce for itself, work that addresses the complexity that
I have only given a very small part of?


I would expect that at first very few things would be made locally.
Maybe only O2 from CO2 and extract small amounts of water from the
atmosphere as a by-product of getting O2. But rapidly, colonist would
want to grow their own veggies or something else. After that more and
more stuff would be made locally.

Before the first colonists arrive at Mars, they would probably have some
sort of plan about when they will start doing this and when they start
doing that. But once there, they will change the plan according to their
needs. That doesn't mean that making the plan aforetime isn't useful.
You need to know all the prerequisites before you start trying to do
something and those prerequisites aren't always completely obvious. And
if, as I said above, you want to grow veggies quite soon, maybe you
shouldn't start by building greenhouses to grow them. Maybe your
priority should be to do something else which gives a fertilizer as a
by-product. Having a plan before leaving helps to know those kind of
links. But once the colonists are aware of those links, they will decide
on their own whether having a smelter is more or less urgent than
growing coffee.

I would also expect that Martian colonists will find solutions with
maybe less performance than what we have here on Earth but have the
advantage to be easier to do. So maybe your rubber O-ring which needs so
much infrastructure to make could be replaced by a much easier to make
O-ring. Then you organize things so it can easily be replaced every
week. If that isn't possible for some particular usage, order high
quality O-rings from Earth for a few more decades.


Alain Fournier

  #3  
Old August 31st 18, 01:55 AM posted to sci.space.science
Thomas Koenig
external usenet poster
 
Posts: 47
Default Make vs. buy for a Martian colony

Alain Fournier schrieb:

But once the colonists are aware of those links, they will decide
on their own whether having a smelter is more or less urgent than
growing coffee.


Making a smelter isn't all that easy, and even so, will the material
you produce actually be useful for anything?

The colonists will probably have to make steel if it is to be used
for anything useful, so you have a two-step process already.

The material should probably withstand the cold on Mars, it will have
to be austenitic steel. So, be ready to alloy it with Nickel,
Chromium and Molybdenum. You may be in luck finding Iron Nickel
metorites on Mars...

Then, have your factory ready to convert this into bar stock.
Next, it goes into the workshop.

Unfortunately, machining austenitic steel is quite difficult.
You need excellent tools and lots and lots of cutting fluid,
which needs to be pumped around. This, of course, needs pumps and
gaskets and... Also, you tools will of course wear out. So,
before you try to machine Austenite, better have your tool
steel production up and running... and make sure to get that
Carbon content right, or you will not succeed. Also, of
course, you'll need the hardeing...

Good thing that the lubricants for the machine tools have already
been manufactured, from the lubricant factory that was set up
before the first ever machine shop ran out of lubricants that
the colonists brought with them.

By the way, if the bearings on your mill break, did you stock enough
spares? Or are you going to set up a ball bearing production?

Etc, etc...

Long story, cut short: I see little problem getting a colony up
to ~ 1850 tech. But that is not going to help a lot in helping
survival on Mars.

At the moment, around 7700 chemicals are produced

I would also expect that Martian colonists will find solutions with
maybe less performance than what we have here on Earth but have the
advantage to be easier to do.


How many people do you think would be required for that?

So maybe your rubber O-ring which needs so
much infrastructure to make could be replaced by a much easier to make
O-ring.


"Maybe" is not good enough in this case.

What other material do you propose for an oil-resistant gasket?

Polychloroprene? Chlorinated Polyethylene? Nitrile rubber (well,
we had that one already)? Polyurethanes? Silicone?

There is no simple way to make an oil-resistant gasket. Each and
every method known to us needs many chemicals, and very many complex
processes that took decades and decades to bootstrap here on Earth.

And really, that gasket was only a random example of something
that we take for granted on Earth - just order it.

Take a look at what the moon spacesuits had for materials, then try
to come up with the supply chain for each of those. And please
don't skimp on the material quality, nor the UV absorber, of the
Polycarbonate helmet bubble. It's no fun wearing a spacesuit if
the helmet becomes brittle and starts cracking under UV radiation
while you are outside...

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Elon Musk is working on a Martian colony Robert Clark Policy 8 February 15th 13 07:17 PM
Elon Musk is working on a Martian colony Robert Clark Astronomy Misc 7 February 15th 13 07:17 PM
What We Do we make a living by what we get. We make a life by what wegive. &Winston Churchill .visit us at ali khanbaba Amateur Astronomy 0 May 31st 09 05:05 PM


All times are GMT +1. The time now is 01:55 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 SpaceBanter.com.
The comments are property of their posters.