Mars Colonization Discussion Thread

[tater]

38 minutes ago, DerekL1963 said:

Define non-critical...  I mean, the ice cream machine is certainly non-critical, but what about the refrigeration equipment?  Without it, we don't die per se, but we could lose almost all the electronics that support our reason for being there (refrigeration equipment chills the water used to chill the air used as a heat exchange mechanism).  The same equipment also chills the chill box (a giant refrigerator) and the freezer that holds most of our food...  Losing that won't kill us (we can always fall back on dry goods and dehydrated goods), but it will sharply limit mission duration.

It sounds silly, but it's a serious question.  There is a broad range of varying shades of grey between  white ("successful mission completion") and black ("everyone evacuates or dies").  A large amount of maintenance effort goes into maintaining systems that aren't critical to the immediate or short term goal of keeping us alive, but which are critical to completing the mission.   And that's not including the hours spent on routine housekeeping, inventory and tracking stores, on administrivia such as updating documents, etc... etc...

Those miscellaneous non maintenance tasks are why I keep hammering on the difference between "maintaining the station" and "performing maintenance on the station".  The two terms are not equivalent.  The latter is a subset of the former.

Yeah, this helps a lot.

In the context of Mars, and colonization, there would certainly be more frivolous stuff brought along, but given the difficulties and costs, I would expect very little. Losing the espresso machine might have to wait a few years, but any number of other systems less critical than the CO₂ scrubber (as an example) might well cause significant loss of wellbeing at the very least (going from living an OK life, to bare survival).

I made the mistake of conflating all that, but the level of routine work is pretty high, and for colonization might have to be reduced (5 person-hours per 747 volume is a lot times a whole town/city---of course what else are they gonna do, there is no Spice to gather or sand worms to ride).

4 minutes ago, kerbiloid said:

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So much efforts to justify an ice cream machine purchase?... Wow...

 

In WW2, the USN had a barge in the PTO (made of concrete, no less!) dedicated to providing ice cream.

 

 

[Green Baron]

Submarine and ISS can be evacuated should all go wrong. A submarine can also run to the next harbour or call for help should something vital happen, so vital has a much larger margin than a manned spaceship.

There is no such possibility for a ship that travels to Mars. If there is no redundancy then almost any larger failure can have grave consequences. An accident like Apollo 11 for example would mean death for everybody on board.

Many of the probes we sent have had failures, in the attitude control, the instruments on board, the propulsion, etc. I don't know the percentage, but it is significant. The only consequence is that the mission objective is adjusted accordingly. Electronics don't mourn. A manned ship would be as thoroughly built as possible but, as we know, bad things happen and cannot always be calculated, even in every day's course.

I see the next step as NASA has planned with the station around the mun, to check the technology, the influence of interplanetary environment. ability to plan and execute answers to unscheduled events. With more routine the picture will become clearer. Musk wants to skip these steps and go directly on the journey, which in my eyes is a recipe for disaster.

 

Edited November 9, 2017 by Green Baron

[tater]

To be fair, all the SpaceX Mars envisioning tends to include sending vehicles ahead to the landing site. Plural in the last presentation. Remember, I’m not a colonizing Mars person, so I’m not supporting it, but I think the counter arguments should be “steel manned.”

So a notional SpaceX Mars mission would involve 3 craft landing. Of course if 2 are cargo, there is not redundancy on a return trip, as those ships have no crew area. A more sensible version might have 1 cargo, and 1 crew sent ahead, then the people (a few to visit, not to stay) in a second crew vehicle.

[DAL59]

12 hours ago, Nibb31 said:

• If you have to live underground to protect yourself against cosmic radiation,
• If you have to decontaminate everything that comes in,
• If everything outside is sterile and toxic,
• If you have to rely on closed-loop technology to survive,
• If there is nothing of any inherent value in the environment,

1. The radiation is not actually that high, as debunked by Zubrin many times.

2. Suitports

3. There are subsurface glaciers.

4. You do not need closed loop life support.  You can extract water and air from the martian environment.

 

 

1 hour ago, PB666 said:

The Mass required to build just one of these and provide ambient non-inertial reference frame comparable to earth's surface is well beyond any serious proposal.

http://www.armaghplanet.com/blog/the-amazing-aldebaran-spacecraft.html

Also, asteroid mining.  

1 hour ago, Green Baron said:

I see the next step as NASA has planned with the station around the mun,

What is the difference in medical knowledge gained from a lunar orbital station than from the ISS?  The DSG seems to exist solely to give money to boeing and lockeed martin.

1 hour ago, Green Baron said:

any of the probes we sent have had failures, in the attitude control, the instruments on board, the propulsion, etc.

And many of those problems could have been fixed by humans...

Edited November 9, 2017 by DAL59

[tater]

36 minutes ago, DAL59 said:

1. The radiation is not actually that high, as debunked by Zubrin many times.

Then he literally has no idea what he is talking about.

 

36 minutes ago, DAL59 said:

What is the difference in medical knowledge gained from a lunar orbital station than from the ISS?  The DSG seems to exist solely to give money to boeing and lockeed martin.

DSG is make-work for SLS/Orion, to be sure. The radiation environment is far worse, and the proposed station doesn't mitigate that at all. I'm not a fan.

 

36 minutes ago, DAL59 said:

And many of those problems could have been fixed by humans...

At vastly greater cost than just sending more, and cheaper probes.

[PB666]

1 hour ago, Green Baron said:

Submarine and ISS can be evacuated should all go wrong. A submarine can also run to the next harbour or call for help should something vital happen, so vital has a much larger margin than a manned spaceship.

There is no such possibility for a ship that travels to Mars. If there is no redundancy then almost any larger failure can have grave consequences. An accident like Apollo 11 for example would mean death for everybody on board.

Many of the probes we sent have had failures, in the attitude control, the instruments on board, the propulsion, etc. I don't know the percentage, but it is significant. The only consequence is that the mission objective is adjusted accordingly. Electronics don't mourn. A manned ship would be as thoroughly built as possible but, as we know, bad things happen and cannot always be calculated, even in every day's course.

I see the next step as NASA has planned with the station around the mun, to check the technology, the influence of interplanetary environment. ability to plan and execute answers to unscheduled events. With more routine the picture will become clearer. Musk wants to skip these steps and go directly on the journey, which in my eyes is a recipe for disaster.

 

https://en.wikipedia.org/wiki/USS_Thresher_(SSN-593)

I suppose that the critical limit of a submarine a feather dropping on the floor could cause an implosion (or overheating Ice cream machine on the interior wall of a submarine).

The general opinion with regard to the Thresher is that the submarine program was being mismanaged with proper management the number of catastrophic events decreased so management strategies are something that needs to be take seriously even if they involve ice-cream machines.

Quote

"I believe the loss of the Thresher should not be viewed solely as the result of failure of a specific braze, weld, system or component, but rather should be considered a consequence of the philosophy of design, construction and inspection that has been permitted in our naval shipbuilding programs. I think it is important that we re-evaluate our present practices where, in the desire to make advancements, we may have forsaken the fundamentals of good engineering." Adm. Rickover

This I think is in line with the critiques of ISS management, that for a more safe and independent deep space voyage the systems need to be more robust. The problem with the Thresher was they were trying to do nuclear age stuff but with a legacy of WWII class submarine, which was a great improvement compared to early 1942 (Namely grossly malfunctioning torpedos).

[DAL59]

27 minutes ago, tater said:

At vastly greater cost than just sending more, and cheaper probes.

Which don't establish colonies...

28 minutes ago, tater said:

the proposed station doesn't mitigate that at all. I'm not a fan.

Me neither.  As Zubrin said, its like "shooting soldiers to study wound pathology"  

[tater]

You were replying to a comment about probes.

Robots would likely be better at colonizing Mars than people, actually. 

[Green Baron]

I suggest anyone who thinks a suitport is a handwavy thing embarks on a sailing trip, let's say 6 days on the Atlantic, in a 14m sloop (that's bigger than most Atlantic crossings can afford). Suitport is the head because no saltwater suit gets into the cabins or even behind the companionway. You'll never have dry clothes again otherwise. After 2 days the plastic suits start to smell, they are wet and they don't dry. After 3 days you start to hold your breath when taking the jacket on. But there are three more days.

And if it is your wake, you dress it and go out, in rain, sun, waves whatever. And there is breathable air, you can scratch your nose or your back if it itches.  Oh, and when your wake is over you enter down and hang your stuff between that of others.
 

58 minutes ago, DAL59 said:

2. Suitports

See above. Try it out, then judge it.

58 minutes ago, DAL59 said:

3. There are subsurface glaciers.

Source ?

58 minutes ago, DAL59 said:

4. You do not need closed loop life support.  You can extract water and air from the martian environment.

That is the dream for the far future. It is unknown if there is enough water and if it is obtainable. Air ? A source would be nice. And you need everything close (a few hundred meters), not water from the poles and air from equator ;-)

58 minutes ago, DAL59 said:

Also, asteroid mining.  

Doesn't exist. Is being thought (dreamed ?) about.

58 minutes ago, DAL59 said:

What is the difference in medical knowledge gained from a lunar orbital station than from the ISS? 

Trivial, the effects of interplanetary radiation as well as that of particles is largely unknown. "Hide between the stuff" is only a helpless excuse until more is known. Only a few people have been outside of earth's magnetic field for a few days.

58 minutes ago, DAL59 said:

The DSG seems to exist solely to give money to boeing and lockeed martin.

Eh ?

58 minutes ago, DAL59 said:

And many of those problems could have been fixed by humans...

Again, grammar matters: will have to be fixed by humans ;-) and for most the fixation will have to be researched :-)

 

[DAL59]

29 minutes ago, tater said:

Then he literally has no idea what he is talking about.

He has a phd in nuclear engineering

[Green Baron]

11 minutes ago, PB666 said:

https://en.wikipedia.org/wiki/USS_Thresher_(SSN-593)

I suppose that the critical limit of a submarine a feather dropping on the floor could cause an implosion (or overheating Ice cream machine on the interior wall of a submarine).

The general opinion with regard to the Thresher is that the submarine program was being mismanaged with proper management the number of catastrophic events decreased so management strategies are something that needs to be take seriously even if they involve ice-cream machines.

This I think is in line with the critiques of ISS management, that for a more safe and independent deep space voyage the systems need to be more robust. The problem with the Thresher was they were trying to do nuclear age stuff but with a legacy of WWII class submarine, which was a great improvement compared to early 1942 (Namely grossly malfunctioning torpedos).

Very good example, the Thresher tragedy. The investigation revealed major construction flaws like no clear difference between "inside" and "outside". A broken pipe of 2cm can fill a compartment in seconds under that pressure. Much was learned.

Having a similar disaster in space  with a BFS because some basic things weren't thought of would throwback space exploration for decades because public perception would suffer greatly.

Edited November 9, 2017 by Green Baron

[DAL59]

2 minutes ago, Green Baron said:

It is unknown if there is enough water

There is humidity in the air.  

2 minutes ago, Green Baron said:

Doesn't exist. Is being thought (dreamed ?) about.

True, but I meant that it could be used to make the orbital habitats you were talking about.  

3 minutes ago, Green Baron said:

Eh ?

 

4 minutes ago, Green Baron said:

Only a few people have been outside of earth's magnetic field for a few days.

We've sent radiation detectors into interplanetary space for years.  The amount of radiation is well known.

5 minutes ago, Green Baron said:

And you need everything close (a few hundred meters),

Why not go to a crater where there is a pool of ice in the middle?  

[Green Baron]

3 minutes ago, DAL59 said:

There is humidity in the air.  

Between 5 and 60% and it's almost nothing, absolutely spoken ;-) We've been there ...

[DAL59]

There's still enough to process into water for drinking.  In fact, its launching on the 2020 rover.  

7 minutes ago, tater said:

Robots would likely be better at colonizing Mars than people, actually. 

This could be true within the next few decades due to AI.  However, for the time being, the teleoperation time delay is a large hindrance.  

[PB666]

Just to repeat there is virtually no water vapor in Martian Air. The air is too cold and too low pressure.
Water was attracted to the Martian poles in the form of CO2 clathrates, because of the lack of sunlight water locked into the poles is more stable.

I think some folks are getting confused, seriously, about water. Yes there is water (brine) on Mars, but it does not exist everywhere, and where it exists is for a short time being pushed up from some geological process is then oozes right back down into the substrate. Its not a matter of this is a nice spot, lets scoop up water. Its more like yuo have to anticipate where the brine will flow, capture as much as you can, then convert it into pure water.

Nighttime temperatures of mars is -100'F close to -73'C. The vapor pressure of water at that temperature is 0.2562, the vapor pressure of Mars is 600 Pascals, the baseline proportion of water in Martian Air can never exceed p=0.00427, it can increase in the daytime, but over much of Mars there is simply no source for water. At 60% humidity (highest being at night) is p=0.000252 (in other words less than 2% of the mass of the air). Again 60% humidity is not likely near the equator. The pressure on earth 101,000 Pa in which 0.044 moles per liter. On Mars this would translate to 6.818x10-8Moles per liter. 

This translates to 0.0000012444 grams per liter of Martian air. To get a liter of water you would need to dehydrate 816 billion liters of air. In that process you would have to separated from several more magnitudes of toxic martian dust that you would also collect.

Edited November 9, 2017 by PB666

[DAL59]

There is still a lot of water ice in craters and at the poles.  

And in the soil. 

[tater]

Nuclear engineering != medicine.

You need to also remember that Zubrin is talking about a flags and footprints mission. A few handfuls of people in a space radiation environment for ~2 years each. Not colonists living in that environment for the rest of their (probably short) lives.

[PB666]

8 minutes ago, DAL59 said:

There is still a lot of water ice in craters and at the poles.  

And in the soil. 

Your power supply for living at the poles?

[DAL59]

The regolith can be piled on the habitats to block radiation.  

Just now, PB666 said:

Your power supply for living at the poles?

There's still ice in craters.

[Green Baron]

i am sure it is on the list of potential future landing and probing sites. Patience we must have :-)

[PB666]

27 minutes ago, DAL59 said:

The regolith can be piled on the habitats to block radiation.  

There's still ice in craters.

Thats not an answer.

[tater]

Buried habitats are clearly a good idea. My argument is with the idea that the radiation is unconcerninng. Docs I’ve listened to on the subject tend to disagree with Zubrin.

For flags and footprints it’s probably easy to find people willing to take a risk perhaps akin to being a smoker. The larger concern would be embryological I would think.

[Diche Bach]

5 hours ago, PB666 said:

What you showed [VIdeo of Cylindrical Habitat] is physically not possible based on current materials science.  A cyclinder even 1/10th that diameter (e.g. babylon 5-ish) is still difficult, I would argue. A larger cylinder is a larger target and asteroids traveling around at 20-70 km/second, the shielding on such an object would have to be massive. 

The third problem is that your source of energy would be entirely artificial since, 1. The ends hold up the floor and glass is not structural, but sheathing.  2. The length of the structure either has the light always coming in at an oblique angle or a reflector (not shown). The optimal structure is a much thinner disk where the light come in the center as is reflected to the sides by a mirror. This is much thinner and allows more colonies and less risk of a catastrophic failuer for each colony.

The Mass required to build just one of these and provide ambient non-inertial reference frame comparable to earth's surface is well beyond any serious proposal.

You must find a source of mass in space first and a means of converting mass into the basic elements required to build such structures.

We can think of it like this, The earth, the place you stand, coalesced over 5 billion years, the heat it gained during coalescence has been evolving also for 5 billion years, energy that has been lost to the earth. To create earth like environment in space you have to impart all the ambient (non-radioactive, no solar hv) heat that the Earth has lost during the 5 billion years.

Also, your gravity, is not what you think, If you drop a ball its on a sub-orbital trajectory. If the earth is not there (but somehow the energy is) it go into a orbit about that point a barycenter between the earth and the moon. If we take the briefest moment of motion you are in orbit, at the end of that moment the Earth steps in to force you back to where you were. It is the stacks of matter that are pushing you up. While it does not appear to be the case its a dynamic equilibrium that occurs between all objects on the surface in motion, the appearance of immobility is due to the way relative motion appears. An example of this dynamic are objects floating on the tides as the tides role around the Earth. If you read the articles on  the Cartesian coordinate system they point out the Z coordinates for all objects relative to the earths true center are always changing at least twice a day sometimes 4 times a day the motion changes. While the structural aspects of the Earth are able to resist most change, they cannot resist all changes. Because the motion is very slow its all but unnoticeable. This change is very minor with small spherical and compact objects in space that try to maintain a non-inertial g-force on the surface, but as objects get more massive these shifts in force become more apparent. If you have an extremely massive structure and you spin it to simulate earths surface gravity the sun (or other local bodies) will cause that structure to begin pulsing. IN order to prevent damage that structure would need to be heavily braced from its center. 

Lets imagine a cylinder 10 km across. To achieve 9.8 meters per second you need a velocity of W2R. 0.98/1000 = w² . omega = 1/31.6 radians per second (About 2 degrees). The entire structure making a revolution in about 3 minutes. If you were inside the structure you literally would hear it creeking and cracking, houses would be in a constant settling. Nails would not be used because they would eventually be pulled apart.

 

Interesting! I had no idea Professor O'Neill was quite such a quack! 

[DAL59]

Just now, Diche Bach said:

Interesting! I had no idea Professor O'Neill was quite such a quack

No!  It is a perfectly legitimate design and is structurally possible as long as it is less than a dozen kilometers in radius.  Also, nothing would vibrate if they inside a cylinder rotating at a constant speed.  Inertia.  

[Diche Bach]

6 hours ago, DAL59 said:

He has a phd in nuclear engineering

Which suggests he probably knows a lot about nuclear power plants and perhaps nuclear weapons, certainly the physics and chemistry surrounding nuclear power plants in general. Also it suggests he is a generally intelligent person.

It does not necessarily suggest he knows what he is talking about when it comes to the radiation exposure a human would experience on a two year stay outside of Earth's magnetosphere, with part of that time in interplanetary space and part on the surface/sub-surface of Mars. For that, I would sooner consult 2 or 3 post-doctoral fellows (all serving under different Master . . . erm, I mean "Advisers") preferably all of whom either know each other and share a mutual animosity or who do not know one another at all, and have no shared academic ancestry.

I have a Ph.D. in psychological anthropology. Doesn't mean I'm an expert on any specific psychological or anthropological topic, much less anything more far afield than that. Not to mention, many Ph.D.s are some of the least rational, opinionated and disagreeable people you will ever meet. The only thing acquiring a Ph.D. proves with some certainty is endurance!

One of my heroes, Freeman Dyson, on his views of the Ph.D. system

 

Edited November 10, 2017 by Diche Bach