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Not being an engineer I do not know enough to really judge the technology of Boeing's plan. What I do know is there are a couple differences between Boeing and SpaceX that will determine what can be expected from them. SpaceX is a small company with something to prove and a name to make. Boeing is a large establish company who long ago made their name. They are currently more interested in maintaining market share than expanding their horizons. SpaceX has a single man in control of what their mission statement. This allows them maintain longer range goals and take greater risks. Boeing is run by a board of directors that for the most part will always choose short term profits over long term growth.
Though this reality frustrates me I do not blame Boeing for it because I suspect the same may be true of SpaceX ten years after Musk has passed away. Here is hoping Elon Musk lives to be very, very old.
I realized after making the post that I was referring to the wrong process. On the plus side it made for a much more interesting title.
One thing has occurred to me is that you would need to locate the well a safe distance away from the colony as if you continued the process eventually a sink hole would be created.
Yes a manually operated system with a little hand-turned crank could work just as well and might be the simpler thing. My thought was if were already running a lot of power to the LED's it's fairly simple to throw some servo-motors on-top of that and let it all be computer controlled. It comes down to the amount of crew time your willing to expend on working the garden though I guess the shelf adjustments do not really amount to much time if the system is easy to use (flip a locking lever, spin crank, re-lock lever). Lights should probably remain under full computer control as plants need to have a specific 'diet' of light through their growth cycle as well as their periodic 'sleep' darkness periods and it would be a waste of time to have people constantly making these little adjustments when they are so predictable.
The sides of the ladder were never what concerned me, it was the hard ground. If your putting an inflatable in contact with the ground as in the bouncy-castle (we have them here in the US too) I don't think it's got the mobility to go around the greenhouse anymore as I'd always imagined very narrow aisle of ~1m wide. Which brings up another point, why not compress that aisle space when not in use? Much like the large book-cases with cranks you see on the side at archival libraries. That would give yet another 100% volumetric efficiency improvement if the shelves and aisle are the same width (I think this means were at ~1% of the footprint of the sun-lit farm by now), though at the cost of significantly heavier ground railings and probably the need for a cement floor. Also at this density I'm quite sure that heat dissipation is a BIG problem, even if the LED's were perfectly efficient the inefficiencies within the plants chloroplasts themselves would be turn most of the input energy into heat which they must dissipate to the air generally by transpiration resulting in a sauna like environment. Their will need to be a lot of air-handling to take this greenhouse air out to the rest of the habitat where it can hopefully fulfill the heating needs their. It might even be more heat then the rest of the habitat can dissipate and we need to dump it (the heat not the air) too the outside environment. And on top of that you have moisture handling needs too, a big condenser is going to be needed to dry the air so the plants can be supplied with dry enough air for them to continue to transpire the water that they are being fed to from the condenser so at least we should be glad that it's a closed loop.
For the issue of the ladder, a number of commercial vertical farms us sets of rotating shelves. The reason for this is it simplifies watering the plants. Rather than having irrigation on each shelf you have a trough at the stack and each shelf rotates through it. I believe this is to provide a more natural cycle of saturation and aeration of the growth medium. This might make adjusting the shelf height more complicated but it may be possible to make a system that did both. With a rotating rack attention to any one shelf is easily done when it is near the floor.
For the heat issue, rather than venting atmosphere would it be more effective to pump it into a "basement" where the martian permafrost could act as a heat sink.
I think what I get from this is that my idea is basically sound. Water will likely not be as difficult as has been suggested for a colony. It appears most places on Mars you will be able to drill a well, apply heat and pull up enough water to sustain a colony.
Location is definitely an entirely different issue and I think I will take it up in a different thread.
I like the sounds of that first link, 3.5 km of permafrost. It would make mining a bitch but it would make getting water a non-issue.
I found an interesting link that talks about where to find the nitrogen. http://space.stackexchange.com/question … t-nitrogen
It seem once refining begins they will have all the nitrogen they need. Some type of solar furnace should do the trick.
This is a bit of a way out idea but I thought I would throw it out there. One of the bottle necks to the development of a colony on Mars is getting enough water and volatiles to support the colony. There is evidence from impact craters that there may be more than enough water but it may just be frozen underground. My idea is to use a processing similar to fracking to get at it. The key would not be so much to fracture the rock as to heat it. It might be possible to start the process simply by compressing the martian atmosphere and pumping it underground. Because of the limit on the actual amount of heat delivered by a gas it is likely this may only be used to prime the well and once the process is going a portion of the water drawn up would be heated and pumped back down. It is very likely the process would also bring up other valuable products like methane and other hydrocarbons.
So let me know how far of the reservation is this idea?
I think the idea that this is a 'plot' against SpaceX is seeing this backwards. I think NASA would like nothing more than to see Elon Musk succeed. The reason for this is once people "believe" space is someplace you can go their funding will grow exponentially. This is what happened with Apollo, everyone believed in it so the funding was there. Musk is already having this effect and that is what this plan is about. Boeing is not trying to beat SpaceX. Boeing will not begin this plan on their own dime. This is just a request to NASA to have them pay Boeing to do this. SpaceX is planning a private venture. Its goal has little to do with a few exploration mission but is designed to establish a viable colony on Mars. Boeing is not looking to derail SpaceX, they just want to get on the bandwagon so they can get their share of the gravy.
One of the overriding concerns with food crop on Mars will be the maximum output over time for the minimum space. For this reason I think the first farms on Mars will look similar to the commercial vertical farms that exist. Current vertical farms mostly produce greens. The obvious reasons for this is that they require a limited amount of space and provide constant output. I think on Mars it would also have the benefit of consistent oxygen production. Dark greens will likely be better choices not just for their nutritional value but also because the are likely require less sunlight. The drawback of greens is though their nutritional value is high in some areas it is also very narrow. They provide little or no proteins and calories.
Legumes will likely be a very good choice. They can be a good source of proteins, carbs, oils and fiber. Most will likely be fairly easy to cultivate in some type of vertical farm setting.
Mushrooms while they make a pretty good replacement for meat in a recipe does not replace much of the nutritional value of meat. Mushrooms do provide a good source some minerals uncommon in other foods and vitamin D. They also have the benefit of not needing sunlight at all.
Though I think initial settlements will have a very narrow range of crops I think expanding the variety of food produced will be a priority. This will not just be to add variety to the colonist's diet but to create a more stable farming environment.
I do not think any type of tree will be cultivated for a long time. It will be very expensive in terms of space and tends to be a long delay before output begins. I think grains will be uncommon as in general they are better adapted to open spaces than a greenhouse environment, much lest a vertical farm.
Some issues that I have not seen here. For manned exploration I believe making the first mission to be one to Phobos would "appear" to many to be not worth the effort. As much as I would like it to be otherwise appearances make a big difference on if a mission ever gets funded. If any manned mission was proposed to go to Mars that did not include landing it would never get approved. Also though much of the science that could be carried out on the martian surface could be done on Phobos much of the science could not be done on Phobos. In addition the result done on Phobos could not be as conclusive as results from research done on the surface of Mars.
The issue for a colony deal first with resources. All of of Phobos would only provide the same resources available 500 m down with 60 km of the colony. The resources available are likely to contain more water and other resources that will be essential to a colonies survival. This can be ensured by carefully choosing the colony site, something that will not be much of an option on Phobos. Making a colony economically viable on Mars is likely to be much easier than on Phobos. Finally the building of a colony on Phobos would likely deal with much bigger engineering challenges.
I think Phobos is a logical location to build facilities to support activities already ongoing on the martian surface but I do not see it as being the first stop.