Wednesday, October 8, 2014

Fixing Mars One

Starting w/ this analysis via Rand. I will select statements to comment on. My goal is to modify the Mars One plan to deal with justified criticism so the end result is viable and does work. Their analysis tool has some serious flaws which I will point out.
The establishment of a colony on Mars will rely on in-situ resource utilization (ISRU) and life support technologies that are more capable than the current state of the art.
Paragon life support is the state of the art. However, dependence on earth resupply of critical systems no matter how good they are, does make this a suicide mission. We can completely eliminate this risk. We will also know, before any human goes, the minimum ISRU production rate of water and power. Humans on site will increase this rate providing a resource cushion.
...resupply logistics and sparing will play a large role in the proposed colony, though the magnitude and behavior of these two effects is not well understood.
This is absolutely a mission risk. Which is why we should diminish the impact of resupply. Done correctly, it can be eliminated altogether and make colonization more viable and increase the potential for long term success.
If crops are used as the sole food source, they will produce unsafe oxygen levels in the habitat.
x
...the ISRU technology required to produce nitrogen, oxygen, and water on the surface of Mars is at a relatively low Technology Readiness Level.
x
A spare parts analysis revealed that spare parts quickly come to dominate resupply mass as the settlement grows: after 130 months on the Martian surface, spare parts compose 62% of the mass brought from Earth to the Martian surface.
x
The space logistics analysis revealed that, for the best scenario considered, establishing the first crew for a Mars settlement will require approximately 15 Falcon Heavy launchers and require $4.5 billion in funding, and these numbers will grow with additional crews.
x
Mars in-situ manufacturing will have a significant impact on reducing the mass and cost of Mars settlement architectures.
You bet it will. This should be our first assumption with cases to back it up.
ISRU is still at a relatively low technology readiness level and as such the mass, volume, and power required by these systems are quite uncertain.
We don't need to know these exact parameters. We just need to know a boundary they are contained within and make sure we go beyond that. Safety demands it. We eliminate the uncertainty that way.
This sparing analysis determines the required number of spare parts to provide a probability greater than 0.99 that enough spares will be available to execute all required repairs during the time between resupply missions.
This is a flaw in the analysis in that it does not consider on-site machinists and 3D printing to make spare parts rather than shipping them from earth. Mean Time Between Failures does not tell you which part will need replacing requiring all parts to have spares. Making only the parts that need replacing significantly reduces resupply mass and eliminates it entirely if a source on mars for materials can be found. This is why the first team needs to include both a chemist and machinist. Two of each preferably.
...there is a high uncertainty in the reliability and size of ISRU systems.
x
...there has been no announcement from SpaceX regarding the development of a scaled-up version[of a mars lander].
Perhaps not directly, but it certainly is their intention to land on mars. If the proposed lander (2,500 kg for $150m w/ up to 4 crew) does not become available that saves us all a lot of bother, doesn't it?
...there is much uncertainty in the ultimate sizing of the crop system for flight systems.
I have no idea why they mention 'flight systems.' Again we can eliminate uncertainty by not depending on any specific growth rate. A single lander can provide 2,500 kg of dry food or 400 man-days of food. This should be considered emergency back-up. Crop size is entirely scalable, limited only by how many hours they put into it. They will not be sitting around watching the plants grow.
The current operational paradigm for the International Space Station (ISS) relies on the availability of regular resupply from the ground.
Wrong paradigm then, isn't it? ISS can provide good parameters for life support issues, but we have to look elsewhere for the right paradigm (living off the land.)
No operational experience has been gained for long-duration human spaceflight missions (LDHSM) beyond low Earth orbit.
Misrepresents the truth. While there have been no actual LDHSM  to date, every aspect of such a mission has been experienced by humans. There is absolutely zero doubt that it could be accomplished. It's a shame Inspiration Mars lost their vision.
There are many areas (not covered in this analysis) that need to be investigated in detail in order to mature the Mars One mission architecture into an executable plan.
Absolutely and I will address some that I see.
These include the Mars entry, descent, and landing strategy, the power system architecture, and the surface-to-orbit communications strategy.
EDL is assumed. Otherwise what's the point? Power has been defined, although not enough (in more than one sense.) Communications has a vendor, just like other parts of the plan.
Comment on Fig. 1.
This is known as GIGO (garbage in, garbage out) as I will explain.
One of the first inputs into the Habitation Module is the assignment of a schedule to each crew-member.
Oh. My. God. They are going to live the entire rest of their lives on mars. Let me interpret... In order for our model to work we must remove all humanity and turn these people into our puppets. While it's useful to know if they have more tasks than hours in a day...this is extreme. They are trying to micromanage...
...resource consumption and metabolic exchange rates...
Simply allow for a cushion and be done with it.
...and handle varying crew metabolic waste loads as they move through a given habitat module. 
OMG!! It just gets worse. They want them to shit on schedule. Don't adults know how to do this without a task list? Yes, they need facilities. No, they do not need a schedule. The body has its own. I bet these kids at MIT are so very proud of how they thought of every thing!

Ok, this is good. They give some thought to failure modes...
Crew starvation, dehydration, hypoxia...
Let me step back and look from a higher perspective. These are going to be responsible adults that can do math. They will have access to both production and consumption rates. They will have backup on earth to check their math. They will know well ahead of time if they have to adjust their behavior to avoid resource depletion. They will have standard on hand levels. If they get hot, they will have a means of cooling. If they get cold, they will have a means of heating. They should always have too much power rather than not enough. This means on hand reserves. This means back up generators. This means on hand level of fuel for the generators. We provide them with more than they need and a means of increasing that. We remove the uncertainty and we do it with local resources. We don't send them with a fragile plan.
CO2 poisoning, Cabin underpressure, Fire Risk
Large living spaces mitigates this and other issues. Atmospheric issues should fail gracefully with plenty of warning, giving time to act. Everyone should have a basic understanding of the chemistry required to provide life support. We get them out of the cans ASAP and only use them for emergency back-up. If it comes from earth it is emergency back-up. Got it?
For each crewmember, 8 hours of sleep and 2 hours of exercise are budgeted per day.
Have I used up my full allotment of OMGs yet? I have to step back again and ask, "do these guys understand the colonists are going to be living on a planet?" Their model seems to make the error of treating this as a space ship. It is not. It is not a mission. It is life. Responsible adults can handle this as long as they have enough initial resources and this model isn't going to define that. Resources will be determined by effort and even by luck. Here's some real wisdom from Christopher McKay, PhD...
The crew’s success is a function of themselves, not their technology.
Back to the analysis...
Biomass Production System Crop Selection: The lack of BPS flight experience introduces significant uncertainty to the integrated behavior of the habitat.
Flight experience? I told you they have a mindset of a ship and not planetary home.
The main limitation of the MEC models is the limited number of crops that it can model. This is due to the lack of experimental data...
Do you see the mindset problem here? The colonists will produce the data. Our job as planners is to make sure they have enough resources to garden and learn by doing. Am I seeing this model on page eight correctly? Are they planning on using in-door artificial lighting? The sun shines on mars in just over a 24 hour cycle, They need plastic with UV protection. They can supplement that natural lighting if need be. They can't predetermine production rates... GIGO. We plan on no production with the assumption that will increase in time by a rate the colonists will tell us.

Nine crops? Are they kidding. Talk about driving people insane. Seeds are the best space travelers of all. Send hundreds of different food crops, if not thousands. That will give you your experimental data and you will not have to schedule the planting. Again, adults living a life can figure it out for themselves.

Uh, do they plan on sending live soil to mix with  mars soil or is hydroponics the only option? Each colonist grows their own food and trades with each other. That's how humans living their lives do it. They aren't puppets on strings. Try to make them such and watch how fast they revolt.
A first simulation of the baseline Mars One habitat indicated that with no ISRU-derived resources, the first crew fatality would occur approximately 68 days into the mission. This would be a result of suffocation from too low an oxygen partial pressure...
What, no hours, minutes or seconds? How absurd! We've already discussed how to avoid this. Basic math + responsible adults + consumption and production rates + on hand levels + sufficient initial resources (mostly power.) Rocks are made of oxygen which can be released with enough power. No ISRU derived resources is not a given condition. Water production is determined before any humans even depart. Do you think there might be a problem with this simulation? GIGO. Their simulation assumes that nobody is tracking the various gas levels and no corrective measures are taken. Like I said, absurd.
...supplying all food by growing plants in the same environment as the crew was found to increase the habitat relative humidity level beyond a comfortable limit.
Related to the previous issue. Both have the same solution as, "Doctor it hurts when I do this." To which Groucho would respond... "Don't do this." In other words grow food on the other side of an airlock not in your habitat proper.
Grow 100% of the required food locally, using a separate enclosed plant chamber to decouple the variations in atmospheric composition generated by the plants to those of the crew.
These kids are smart. I figured it out in five seconds. I wonder how long it took this team of whiz kids?
...each of these cases is analyzed in further detail...
I spoke too soon. Not so smart.  I dismiss the other case of bringing all food along (for lifetimes.) You supply complete emergency ration until local production and storage demonstrates they need less. You don't send more colonists until they've demonstrated sufficient production.

Skipping over option A. So on to B...
Introducing an “Oxygen Removal Assembly (ORA)” to transfer excess oxygen from the plant chamber atmosphere to the oxygen tank. This makes use of a valuable resource that would otherwise be vented. It should be noted however, that this technology does not currently exist.
Really? Perhaps these kids should visit grams at the old folks home more often. A portable oxygen unit that compresses oxygen out of the air costs about $5 grand.
...it was found that even though 100% of the food is grown in this case, some food still needs to be brought from Earth to support the crew over the period spanning between their first arrival, and the time at which the first crop batch matures.
I didn't even need a simulation to tell me that. Which is part of the emergency food backup I already discussed.  This is comical. Hey guys, you see these trees? They're part of a forest... just saying...
With the ISRU requirements derived for these two habitation case studies, the corresponding ISRU system can be sized to determine the total mass and volume of active equipment required for the Mars One mission.
Or, just spit-balling here... We give them the ability to increase their ISRU to any level they need so we don't have to guess for them? How about that? That would mean, instead of this absurd analysis to determine precisely how much they need; We instead figure out the tools and designs they need to make it for themselves including on hand reserves they should keep for emergencies. Enough to give them time to fix the problems. These would be individual reserves to avoid single points of failure. They would share because it's their community... not because someone is pulling their puppet strings.
Once the oven geometry/design was determined, a mass estimate was generated using aluminium for most structures and titanium for high-temperature applications.
Could an oven be made out of, I don't know... brick and clay? from mars itself. Do we have to limit them to things brought from earth?

Skipping over discussion of TRL as they obviously aren't aware of what is or is not available. The simple thing is you determine your basic production needs. Then go shopping. There are thousands of little office park shops that will build you anything you need if it's not already in some catalog.  We're talking chemistry which is pretty well understood. Not even chemistry. Getting water out of sand is something boyscouts do in the desert with a rock, a piece of plastic and a metal cup.

The important thing is to keep the designs simple enough for those on mars to reproduce even without a 3D printer which they will have several of. Which can self replicate.
Spares analysis...
They make their own spares. If that's a problem: redesign. I'm only halfway through, but it's the same mindset problem throughout so I'm going to skip as much as I can unless something is glaring. ...and here she be...
At the 10-year mark, the 5th crew is accompanied by over 100 tonnes of cargo, 64% of which is spare parts.
Am I good or what? I just answered this absurdity before asked. My plan says 1 ton per crew of personal property.
These mass savings indicate that using ISRU to support Martian settlements is a clear avenue to system mass reduction.
Considering anything else is a ridiculous waste of time. But they fail to make the next logical leap that the ISRU machinery itself should be producible by the martians.

Conclusions... perhaps I should have just started here?
First, our habitation simulations revealed that crop growth, if large enough to provide 100% of the settlement’s food, will produce unsafe oxygen levels in the habitat. As a result, some form of oxygen removal system is required – a technology that does not currently exist.
Based on the false assumption  that for 68 days nobody would be monitoring or take corrective action, then die. Correction action being as simple as not sharing your living habitat with your farm. ...and the technology is off the shelves although that shouldn't be used. The technology should be a design they can build themselves (although I don't know, perhaps the off the shelf technology is something they can build themselves?) It's mainly pumps and condensers.
Second, the ISRU system sizing module generated a system mass estimate that was approximately 8% of the mass of the resources it would produce over a two year period, even with a generous margin on the ISRU system mass estimate.
Based on the false assumption that the systems are not designed to be built by the martians. Life support fundamental requirement are known and simple... Power: not just solar panels and batteries (they can make more of both) but methane engines and generators in the short term and nuclear in the long term. Water: abundant, they need power and dirt. Oxygen: Water and power. Temperature control: simple heat pump design and power.
Finally, the space logistics analysis revealed that for the most optimist scenario considered, establishing the first crew of a Mars settlement will require approximately 15 Falcon Heavy launches costing $4.5billion, and these values will grow with additional crews.
Finally the most absurd conclusion of all which they disprove themselves.

1 comment:

carlyjj said...

Hey, there is a broken link in this article, under the anchor text - this analysis

Here is the working link so you can replace it - https://selectra.co.uk/sites/default/files/pdf/marsone.pdf