China prepares to grow vegetables on Mars
google.com
google.com
On the plus side (for plants), the Martian atmosphere is about 95% CO2. Even though the total pressure of the atmosphere is much less than our own, the partial pressure of CO2 is still about 20 times higher (erring a bit on the generous side).
On the other hand, Mars is about 1.5 times as far from the sun, so the intensity of sunlight is less than half, and temperatures are correspondingly colder. Then again, if we're going to support human colonists, we probably need a nuclear power source anyway. So let's assume we rig up bright lighting to grow our plants.
There's some uncertainty about the soil, but at least some studies suggest that it could support life. There's probably frozen water there, so we'll use the spare heat from our nuclear reactor to melt some.
Humans need approximately 30g of Oxygen per hour, which is roughly 1 mole. A fast-photosynthesising plant can produce 30 umol/m2/s. Running the numbers, you'd need 9 square metres of leaf area photosynthesising at that rate per person - assuming it could carry on 24 hours a day. To supply food, you'd need rather more, because not all of the carbon fixed goes into edible parts.
This is actually a lot more feasible than I initially thought. You'd probably want to send robots ahead to construct the base and plant the plants, though. And you still have the problem of life support for the journey, which would be several months.
http://english.peopledaily.com.cn/90786/8044143.html
The experiment was a closed biosphere life support system, 36m^2 involving two subjects for 30 days. The article mentions the moon and mars. As I understand it, this thing would be a sealed capsule that you bring with you. This forms part of the ongoing field of CLESS (controlled ecological life support systems). All the references I've seen point to the Russian Bios-3 project as being the first public example of this.
I am also interested to hear more about your ideas regarding the feasibility of martian agriculture :)
A sealed chamber could be pumped up to around earth pressure, making it easier for the astronauts to go in - although with high CO2, they'd still need oxygen tanks. On the other hand, the pressure difference would require a much stronger capsule, so perhaps farmers in spacesuits is the way to go.
There is no air on the moon, so this doesn't seem likely.
The far side of the moon is awesome for science (the most ultimate radio telescope ever) but not so much for growing humans.
How much carbon/coal would you need to support a colony of say, 5 people (+plants)?
On the moon, you'd have to run pretty much ecological "closed system", perhaps with oxygen and water supplemented by industrial processes. However, rapid resupply is possible, and non-fatal mistakes correctable.
On mars you could get away with a lossier system (seems to me, easier access to outside air, water, nutrients), but resupply is so much harder...
Even better, this means you can get a significant portion of your mission hardware (including your return vehicle) ready and waiting on the Martian surface, having survived what is probably the most dangerous part of the mission (landing) before your humans launch.
(Two year launch window gives you time to make sure everything is working, and also gives various in-situ fuel production methods a chance to run their course.)
The only real place besides the surface of either planet where you would want to "dock" with something is the orbit of either planet.
You are right it probably isn't needed, was more just wondering if it were possible or would the speed differences make docking too hard. I guess the slower moving craft would run through a lot of fuel to bring its speed up enough when close to docking.
There are some faster and slower paths. More missions to Mars have taken an 8-month-or-so journey because it's easiest and lowest power, and all unmanned cargo are probably going to take that route.
But by using just a bit more energy, you can cut the travel time down to about 6 months.
Most Mars missions involve launching stuff to land on the Mars surface (or maybe in orbit) that would take the slower path while the humans take the faster path.
(If you really want a bigger craft than you can launch from Earth at one time, just link up in LEO.)
There's air, but not much. And I wouldn't want to try and breathe it.
Don't break out the nukes yet…
No cloud cover is going to push up the average insolation, plus a thinner atmosphere will absorb less. Dust will bring it back down some amount.
Temperature could be handled with insulation. Aerogel might be good here. A thin layer of glass sufficiently hard to survive the blowing dust and then a layer of aerogel to retain heat but still pass most of the light.
Break out the nukes ;-)
Sorry, but this is missing the point in as big a way as possible if you are using a nuclear plant. Even providing half intensity sunlight for large scale agricultural purposes is not feasible from an economic standpoint. Use the intensity of sunlight that's there. You just have to accept higher acreages and longer growing times. That would still enable civilization.
It would probably easier to oversize the powerplant (to generate oxygen, growlights, melt water, treat air and waste) than to try to bring along a whole biological ecosystem. On the first few trips at least...
The advantage with the powerplant approach is that you can live anywhere with rock and ice in the soil (most airless planetoids) or CO2 and water in the atmosphere (Venus, Mars or the gas giants).
Resupply from Earth is slow and expensive - especially when Mars is at the far end of its orbit. And as far as I know, we can't synthesise food artificially. Even if we could make some simple sugars, that will hardly keep the astronauts healthy. So I think growing plants would start to look quite inviting.
But I think the bigger challenge is getting anyone there in the first place. They'd need life support for months. I suspect you'd have to assemble something about the size of the ISS in Earth orbit, then send it across to Mars, and deploy landers to reach the surface.
There might be uses for burning CO on Mars, but not as the byproduct of CO2 splitting for breathable oxygen.
CO + O2 fuel would make more sense on Venus, where water would be more scarce (water is present in thin clouds of sulphuric acid in about 25% concentration). The surface, however, is another business.
More on Venus (a surprisingly appealing place to go): http://www.space.com/5653-cloud-cities-venus.html
And a story by Geoffrey Landis http://www.asimovs.com/2010_09/exc_story1.shtml
A simpler solution is something like that setups that the aquaponics folks run. [1] Basically if you've got electricity (nuclear power) and water (from the soil/ice) you can build pressurized grow room to make food. It would be interesting for these guys to build such a system underground to get an idea of how much external electricity it needed to function.
RTGs are becoming extremely rare since the US isn't making any more. :(
Other efforts, China in particular, seem to attract scorn. Especially in light of the fact that Elon Musk's original plan was to send a greenhouse with plants to Mars.
Perhaps I over-estimate the HN crowd.
Perhaps NASA will get more funding for Mars missions as a result of this. Everybody wins long-term.
It's a shame that it takes a threat of one-upmanship to get people off their asses rather than doing it for the sake of scientific endeavour, but that's human nature.
There's a whole lot to be skeptical about here, but even rumors can kick off a space race.
Perhaps this has something to do with China's absolutely atrocious record regarding:
1) The environment
2) The rest of the world
3) Human rights
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Is it really that difficult to understand that some of us have the foresight to realize that China's method of interfacing with its environment is not something that we want to see tarnishing a yet-untarnished planet?
Truly, an environmental catastrophe. They could render the planet uninhabitable. :(
If they accidentally unleash an Earth origin extremophile, it would have the potential to taint any any life that may already exist on Mars. This hypothetical life on Mars probably isn't of any real use to us, obviously it isn't megafauna or something, but it would be of unspeakable scientific importance. The chance to study live from an independent instance of abiogenesis.. I just can't find the words to describe how important that would be.
(Well, obviously contaminating Mars is itself panspermia, but not really of the interesting sort. A confirmed instance of "natural" panspermia would tell us a lot about what we can expect about the distribution of life throughout the universe.)
Present or not, we need to have some kind of strategy for how to survive there on a long term basic, either for a small-scale scientific mission or on a larger scale to terraform.
Besides, there are several other places in the solar system that have the potential to host life, such as Europa. I don't want we should spend so long sitting on our hands that another generation or more has to die without seeing the human race explore further. It irritates me that it's already 40 years since the last moon landing: http://xkcd.com/893/
What does it mean to "tarnish" a lifeless planet? Or even Earth for that matter? Every single kilogram of hazardous material on Earth was here long before humans evolved; all we're doing is moving around what occurs naturally. In the worst case, the same would be true of Mars.
2) What is China's absolutely atrocious record against the rest of the world?
3) This one is on the spot.
This is not to excuse China's poor record by any means, but your sanctimony is unwarranted.
I basically agree that the USA shouldn't be on a high horse with China regarding environmentalism, since China is doing precisely what the USA did when it originally industrialized. That doesn't make China's environmental travesties OK, but it does rob them of some moral impact, at least from Americans.
I don't want to go way off-topic with this, but it's a pet issue of mine because I think it's a human-rights disaster.
* Those incarceration numbers come from the Chinese government and haven't been audited by any third party (a perennial complaint about Chinese prison statistics)
* They don't necessarily capture every form of detention present in China, including forced labor camps, administrative detention, house arrest, and pre-trial holding.
* Speaking of which, Chinese police can (according to HRW) send people to "Reeducation Through Labor" camps for up to three years without trial.
* Something like 650MM Chinese live in rural poverty in the countryside; China also has a concomitantly low crime rate for its population. Another way to say this is that there are effectively two Chinas in a way there aren't two Americas.
* Not all incarceration is intrinsically bad. For instance, a recent survey of Cook County found violent domestic assaults made up a huge component of all offenders. China has rampant, endemic violent domestic abuse issues. If China is incarcerating fewer people in part because it's doing a worse job of protecting helpless people, that's not a great thing either.
* And of course, China imprisons people for political speech; it imprisons defense attorneys (for "obstructing justice") even in nonpolitical cases; it executes more of its citizens and for a much larger diversity of crimes; its citizens have far fewer due process protections (they can be held effectively indefinitely prior to trial even after recent reforms, they have no right to refuse interrogation, etc); it forcibly sterilizes women in prison; it harvests the organs of prisoners.
We should indeed imprison fewer people and of course end the war on drugs (already, we're seeing sharp drops in the number of people incarcerated for simple possession of cannabis) and our for-profit prison administration is fraught.
But let's keep perspective. It is ultimately pointless to compare criminal justice between a country that has the rule of law (even when that law is unjust) and one that simply doesn't have that. A comparison between the US and China is, unfortunately for both countries, unhelpful.
Really, I love Chinese humor. It's underrated.
This is why translated puns can sound very stupid. It's also why you're likely to sound stupid when you try to pun in Chinese.
And prestige? 1/3 of the Earth's land surface is covered by desert. If you could suddenly transform that from a life-hostile to a life-flourishing environment, you'd win as many Nobel Peace Prizes as they can possibly stamp out.
Adding lots of water is how California turned into an agricultural powerhouse.
Though we should also note that turning desert into (ideally) arable land could have disastrous unforeseen effects; consider how much of the Amazon is fertilized by the Sahara.[2]
“It’s the Gobi Desert,” said Wang Yu, the vice director of economic planning. “There’s not much other use for it.”
http://www.nytimes.com/2009/07/03/business/energy-environmen...
Competition from china is the only thing I can see spurring the USA into action.
Also, China tends to be a fast copier, not a leader. They seem to leave the bulk of development costs to someone else. So I think it's unlikely that they will front the resources it'll take to make a Mars mission possible.
As an aside, as a Non-US citizen of the world, I applaud any effort to get outside of our planet, even more so if they are as ambitious as this one.
What a huge generalisation. This appears to be true in the consumer electronics world perhaps, but look outside of that and it's harder to justify.
For example, China has been building a lot of infrastructure in the past few decades, including the longest and highest bridges in the world[0][1]. There was a story on HN a few days ago about a Chinese company's plans to build what will be the tallest building in only 90 days[2].
Granted there is a lot of press about these bridges falling down, and maybe their rocket will blow up half way to Mars. But you can't say that they aren't pushing things themselves.
[0]http://en.wikipedia.org/wiki/List_of_highest_bridges_in_the_... [1]http://en.wikipedia.org/wiki/Longest_bridges_in_the_world [2]http://news.ycombinator.com/item?id=4807701
For an achievement to "count", I'd make the bold claim that it has to actually work.
* However, I do agree that often to make progress you absolutely have to push your engineering "comfort zone" and try dangerous things, in order to learn from your mistakes. But this does not change my definition of "success", it just acknowledges realities of R&D.
Aerospace and software are industries the West still dominates though. Since HN tends to focus on those this is a common impression for people here, it's not in some other industries.
I think the PRC do have technology and money to put things in outerspace in the near future, what they do not have yet is the know-how.
You could have said the same thing about the US in the first half of the 19th century, and look how innovative we ended up being by the start of the 20th. Or about Japan later on. Societies that are able to copy innovations quickly seldom have trouble generating innovations when they run out of things to copy.
Wasn't there a famous Chinese guy who said something like "never underestimate your adversary".
In the past that might have been true, but things change. Just one example A lot of people have been educated in the US, and are going back to china to start companies.
As a point of order: two year launch window, but a 6 month trip if you wait for that.
Not to say they haven't got something half-functional. I'm just very skeptical that it's as great as they say it is.
EDIT: OK, for the benefit of whoever didn't have a sense of humor, I was suggesting that the astronauts might be planning on bringing some soil with them.
You could have a really good plan to convert martian soil for plant use, but then again, that might fail. This obviously means you can't depend on your garden. Also, what you would have would be a laboratory, not a garden. You would spend a lot more time analysing the food than eating it.
On the other hand, you could carry out a sample return mission, bring some mars dust back, run tests, and land with a solid plan. Only thing is, sample return from mars would make moon rocks look cheap.
Finally, bringing the soil with you would be the most reliable method. It's moon rocks in reverse though! That soil would be, kilo for kilo, the most expensive soil in the history of mankind.
This might require slightly better AI than currently exists, and a lot of patience from telepresence operators, but it seems achievable in the near future.
(N2 also exists in the atmosphere, but at low levels.)
1. Develop system capable of growing plants on Mars.
2. ____________________
3. Grow plants on Mars.Also, you forgot step 4.
Mind you, I'm not advocating that position, but I certainly expect it.
Really, I think the original article was terrible; it omitted important details to make the whole thing sound more silly. Closed biological systems are an interesting field of research.
I'm not sure about radiation levels on a mars mission, but if we can solve the problem for humans, it should be solvable for plants/algae.
Get your hands on this book and read.
"During the experiment, four kinds of edible vegetables, namely lettuce, leaf lettuce, gynura bicolor and sonchus oleraceus, were planted in a 36-square-meter area to absorb the carbon dioxide exhaled by the two astronauts and provide them with oxygen and 30-50 grams of fresh vegetables per meal per person."
Google tells me you need 1 ton of soil to cover 30m^2 to a depth of 25cm. So now I'm interested to know if/how they're optimising for mass efficiency.
Mars is further from the sun.
Actually, this has been studied. There's enough sun with the right timing and thermal balance (provided the right kind of greenhouse) to grow food.