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#1 2002-10-25 15:15:54

clark
Member
Registered: 2001-09-20
Posts: 6,362

Re: Lifetime of advanced machinery - How long can advanced machinery last?

How long can advanced machines last in hostile environments? What are the historical expereinces with our advanced machinery, and how long can it operate safely and reliably?

Any future martian society will be highly dependant upon advanced machinery, and the environement is pretty severe in terms of tempeture swings, radiation, and pressure differentials that will exsist between the environment and the habitable areas.

How long do our nuclear submrines stay in service? What kind of failure rate is acceptable for a *community* living on Mars and still be safe?

This is all part of the long term cost associated with living in space, so it should be addressed.

Anybody have some info or some ideas?

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#2 2002-10-26 10:27:49

Josh Cryer
Moderator
Registered: 2001-09-29
Posts: 3,830

Re: Lifetime of advanced machinery - How long can advanced machinery last?

Ahh, my kind of topic! Damn, I gotta do laundry. We'll probably continue this, though.

It's easy to figure out the life of advanced machinery once you realize why machines break down in the first place. The main reason is friction, and stresses. A machine with moving parts is definitely going to break down if its components are not very precise. Just imagine a gear made of steel that's made in someones garage with simple tools. If that gear deviates by a few microns, there will be stresses every revolution, and over time, that gear will eventually wear down. The key is to have little or no moving parts, and the parts that move, ought to be extremely precise, with care taken to reduce physical stresses related to moving about; you want to exhibit as little friction as possible.

There are coal mining machines in Germany that outlast their operators. And computers, given their few moving parts, are theorized to outlive their builders by generations. Just look at Voyager, or Pioneer, though, to get an idea how good we can build machines.

I have a few manuals from my brothers nuclear submarine from when he was in the Navy. You cannot imagine how utterly complex those things are. It makes me wonder what in the hell is going on there. I mean, their computing facilities are easily using 20 year old technology. When I toured the sub, they didn't let us see any of the consoles (?top secret), but once I acquired the manuals, I could ?see? what was beneath, anyway. I'll never get over it.

Is future technology going to be designed like a submarine? I certainly doubt it! They had one central computer with dozens of smaller ones (all still the size of a large desk, though). All connected with hundreds of countless wires. I expect the computing facilities of the future will be simply connected with a few ethernet wires or whatever. You can look at images of old servers, and new servers, and see that the ammount of wires is decreasing while the capacity to handle traffic and so on is increasing. With precision comes not only long life, but efficiency! I know what you're thinking... the more technological something is, the more complex it is. Well, that may be true from a certain perspective, but from a user perspective, it doesn't have to be. Most people don't likely understand the myriad of ethernet protocols, or how generic ethernet transport functions. But most people can plug an ethernet cord into a terminal!


Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
--------
The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.

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#3 2002-10-26 10:41:42

Byron
Member
From: Florida, USA
Registered: 2002-05-16
Posts: 844

Re: Lifetime of advanced machinery - How long can advanced machinery last?

Interesting topic...  My biggest fear of machinery in the Martian environment is dust, or "fines" as KSR described it.  Unlike Earthly dust, the Martian counterpart is extremely fine, as well as having all kinds of corrosive properties.  No matter how hard people seek to keep this nasty stuff out of the habs, rovers, etc, it's still going to get in there, and it'd eventually find its way into all the sensitive equipment inside the hab, cause static-energy buildup within critical electronic components, etc.  I can only only imagine some of the unpleasant things that could happen as a result of this dust infiltration, not to mention the potential health hazards of breathing that stuff.

And idea of how we'd be able to cope with this potentially very serious problem?  Sure, Voyager has lasted for decades, but it's in a complete vacuum, with not a speck of dust near it...Mars will not only be a harsh place for humans, but for machines as well... 

B

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#4 2002-10-26 12:31:31

turbo
Banned
From: Jacksonville, Florida
Registered: 2002-08-01
Posts: 76

Re: Lifetime of advanced machinery - How long can advanced machinery last?

The hardware is smaller greatly because of Surface Mount Technology, which is not known to be keen on vibration.  Maybe adding a layer of acrylic over the circuit boards will keep the fines away and make sure those components stay put during launch and landing.  Electrostatic filters may be able to deal with fines as well, but those filters would have to be kept well away from the circuitry. 

For the daily dealing with the fines, would it be possible to place electrostatic collection plates around the end of an airlock?  The suit radios would have to be well shielded, but better that than contaminated control circuits in the power or ventilation systems.

Mechanical parts?, sealed units where everything is immersed in mineral oil or hydraulic fluid I guess.  OR...sealed units connected only through magnetic force.

Where there's a will, there's a way
turbo

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#5 2002-10-27 15:33:34

Number04
Member
From: Calgary Alberta Canada
Registered: 2002-09-24
Posts: 162

Re: Lifetime of advanced machinery - How long can advanced machinery last?

About coating the circuit boards, if you ever have to repair anything, you are hooped. Also, heat may become a problem.

As for sealing off moving parts, there are some things that can't. If you have a piston that has to interact with the outside world, sealing if off would be hard. As well, you would need some kind of filter for the fluid incase it was contaminated. But I think that would be our best bet. It's not too complicated and is not at all radical from what we have now.

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#6 2002-10-28 01:46:01

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Lifetime of advanced machinery - How long can advanced machinery last?

As some of you know, I'm not convinced of the validity of the 'super-oxides in the Martian soil hypothesis". Accordingly, I'm not convinced that Martian dust is going to be dangerous to inhale.
    However, I'm not going to grind that axe today. ("Alleluia! And may the Lord be praised!", I hear you all shout!! )

    On the other hand, I am prepared to admit that fine dust is probably going to be a nuisance at best, and maybe dangerous at worst, if it affects vital equipment.
    Would it be feasible to build a valve into the airlock doors so that when the astronauts returning from excursions are dusting themselves off and removing their suits, air is constantly leaking out of the Hab into the airlock, and then out into the open air? In other words could we arrange for 'negative pressure' in the airlock, the way they do with biohazard facilities?
    At least this way we might be able to keep the vast majority of dust outside where it belongs!
                                         :0


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#7 2002-10-28 07:09:46

Byron
Member
From: Florida, USA
Registered: 2002-05-16
Posts: 844

Re: Lifetime of advanced machinery - How long can advanced machinery last?

As some of you know, I'm not convinced of the validity of the 'super-oxides in the Martian soil hypothesis". Accordingly, I'm not convinced that Martian dust is going to be dangerous to inhale.
    However, I'm not going to grind that axe today. ("Alleluia! And may the Lord be praised!", I hear you all shout!! )

    On the other hand, I am prepared to admit that fine dust is probably going to be a nuisance at best, and maybe dangerous at worst, if it affects vital equipment.
    Would it be feasible to build a valve into the airlock doors so that when the astronauts returning from excursions are dusting themselves off and removing their suits, air is constantly leaking out of the Hab into the airlock, and then out into the open air? In other words could we arrange for 'negative pressure' in the airlock, the way they do with biohazard facilities?
    At least this way we might be able to keep the vast majority of dust outside where it belongs!
                                         :0

Thankfully we have people like you who like to question the current paradigms of what the surface of Mars is like... wink ...I can only hope that your thoughts will be vindicated someday soon...

Anyhow, some of the ideas mentioned above seem like good ones, although they still have problems of their own and will add to the cost of early missions...  The idea of using "negative pressure" in airlocks would an exceedingly practical one, however, as that technique is currently used in today's hospitals, etc...no extra equipment would be needed, etc...it'd be just a matter of adjusting the interim air pressure in the airlock, and I suppose you could have a large fan that would shoot air from the ceiling to grates in the floor that would suck out the dust before the suited person enters the hab proper.

Another idea is having a "water lock"...a person would enter the airlock, batteries of water-jets would spray the spacesuited individual with a vigorous flow, like those auto-car washes you see all over the place, and powerful fans would kick in for a few minutes afterwards to evaporate the water afterwards...  I don't see this process taking much more than five minutes or so, and the water can certainly be filtered out and recycled for the the next person coming in from outside.  This way, virtually 100% of the dust would be kept outside, and the process would be automatic and painless for the astronants themselves, as well as never exposing them to the dust itself (I have problems with dust here on Earth...so breathing in its Martian counterpart is something that would be best to avoid as much as possible...why take the chance of 'Martian lung disease'...)

B

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#8 2002-10-28 16:13:35

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Lifetime of advanced machinery - How long can advanced machinery last?

Thanks, Byron! It's always nice to think one's ideas are well received.  smile

    The idea of using water is probably a better idea for cleaning up the 'fines', as it neutralises the potential problem of electrostatic charge. As we all know, dust moving around in an air current can become charged and tends to stick to surfaces.
    Blowing the dust off a table will get rid of maybe 95% of it, but you can't beat a damp cloth or sponge for really getting the surface clean!

    What I was hoping to do, though, was to keep to a very simple, low-tech solution to the problem. Adding the plumbing required for water based cleansing made me nervous!
                                                      ???


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#9 2002-10-28 16:17:54

clark
Member
Registered: 2001-09-20
Posts: 6,362

Re: Lifetime of advanced machinery - How long can advanced machinery last?

What about the wide fluctuations in tempertures that a hab will be exsposed to? What kind of lifetime can we expect or can materials with enough elaticity be used? What metals are best suited for a low pressure environment with huge temp differentials?

How long would glasss survive in this kind of environment?

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#10 2002-10-28 16:35:21

Number04
Member
From: Calgary Alberta Canada
Registered: 2002-09-24
Posts: 162

Re: Lifetime of advanced machinery - How long can advanced machinery last?

I don't know that much about the metals, but you can accommodate for the expansion of metals. I think glass would be allot harder. I think Plexiglas would have to be used. If you are talking about eye glasses, well, they should be on your face and hopefully out of harsh temperatures big_smile

I agree, the plubming needed to do a water bases cleaning system seems difficult to implement at first. Why not just leave the suits out side? Quarantine then from the rest of the hab?

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#11 2002-10-28 16:41:58

clark
Member
Registered: 2001-09-20
Posts: 6,362

Re: Lifetime of advanced machinery - How long can advanced machinery last?

Would a small coating of negativel charged particles (think magnet paint) be an option for repelling dust on Mars? Perhaps the gear that goes outside and inside (the suits) could have a special covering (thin suit condom) that is disposed of with every use (or specially cleaned). Just remove the thin suit, and problem solved.

My main cncern is the ware and tare on the actual base itself- what can be expected?

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#12 2002-10-30 19:26:13

Number04
Member
From: Calgary Alberta Canada
Registered: 2002-09-24
Posts: 162

Re: Lifetime of advanced machinery - How long can advanced machinery last?

I don't think temperature should be a big issue. A hab could be engineered with different layers on it with insulation to avoid any major problems. (In my mind)

Now, as for wind and dust, as long as it's somewhat aero dynamic, I think it should be fine. Keep the hab to 1 or 2 levels and make it long enough for the wind to pass over it.

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