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China prepares to grow vegetables on Mars

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Re: China prepares to grow vegetables on Mars

#111

Post by danielweber »

takluyver wrote: post #54
mogrim wrote: post #49

Earlier quoted context omitted.

Although if you've got water (and there is water on the moon) and a nuclear powerplant generating loads of electricity, getting oxygen's not a problem.

It appears that you don't have much carbon, though (see 'Lunar regolith' on Wikipedia). So once you've got your oxygen generator set up, you may have to fly coal up there to burn for CO2. Once you're set up, though, you should be able to keep the carbon in a closed loop between humans, the encapsulated air and the plants.

It's hard to grow a colony if the things people are made of has to be imported in.

The far side of the moon is awesome for science (the most ultimate radio telescope ever) but not so much for growing humans.

Re: China prepares to grow vegetables on Mars

#112

Post by danielweber »

ChuckMcM wrote: post #98
takluyver wrote: post #33

How well could this work? 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 c…

Hmm and RTG like the one Curiosity is using could be used to charge batteries at night and then run growlights during the day. Excess heat could be captured to keep the temperature up. There is a the radiation hazard of course. 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…

You probably want an actual nuclear power plant for any planet-side mission. The Russian TOPAZ is a model for what we'd want in the long run.

RTGs are becoming extremely rare since the US isn't making any more. :(

Re: China prepares to grow vegetables on Mars

#113

Post by danielweber »

cpeterso wrote: post #101
takluyver wrote: post #33

How well could this work? 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 c…

I wonder what types of plants would be most amenable to growing on Mars. The environment could be simulated in greenhouses (red houses ;) on Earth to cultivate successful plants (genetically-engineered or bred the old fashioned way).

I don't think any earth plant could survive 1% standard pressure. I have read papers on what genes would be interesting to splice here and there to make plants that could survive that, though.

Re: China prepares to grow vegetables on Mars

#114

Post by danielweber »

MichaelApproved wrote: post #16
vitno wrote: post #13

If China manages to do this, then we will have people on Mars in under 2 years. Competition from china is the only thing I can see spurring the USA into action.

Far from. It takes nearly 2 years just to get to Mars. 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.

Far from. It takes nearly 2 years just to get to Mars.

As a point of order: two year launch window, but a 6 month trip if you wait for that.

Re: China prepares to grow vegetables on Mars

#115

Post by danielweber »

stcredzero wrote: post #86

There's a lot of thinking in the comments here which is good for what it is, but which lags far behind engineers and scientists who have thought about it for years. Get your hands on this book and read. http://amzn.com/0684835509

There is a new version people should get instead. Not much has changed but we might as well direct people to the latest stuff:

http://www.amzn.com/145160811X

Re: China prepares to grow vegetables on Mars

#116

Post by danielweber »

Achshar wrote: post #17

But this cannot be of much use, even if they can make an atmosphere somehow, they would need an active core for magnetic field to protect from solar particles/radiation.

The magnetic field on Earth is not what protects you from radiation. It's the thickness of the atmosphere. Lots of radiation is uncharged particles which don't care at all about a magnetic field.

Re: China prepares to grow vegetables on Mars

#117

Post by danielweber »

xyzzy123 wrote: post #14
draq wrote: post #10

Earlier quoted context omitted.

ever heard of supply and demand?

Yep. It gets kind of interesting though when you think about the challenges. 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 retur…

You would want to bring some nitrogen fertilizer, which is what the Mars soil seems to be short on.

(N2 also exists in the atmosphere, but at low levels.)

Re: China prepares to grow vegetables on Mars

#118

Post by stcredzero »

danielweber wrote: post #115
stcredzero wrote: post #86

There's a lot of thinking in the comments here which is good for what it is, but which lags far behind engineers and scientists who have thought about it for years. Get your hands on this book and read. http://amzn.com/0684835509

There is a new version people should get instead. Not much has changed but we might as well direct people to the latest stuff: http://www.amzn.com/145160811X

Sorry, wasn't paying attention.

Re: China prepares to grow vegetables on Mars

#119

Post by tptacek »

anigbrowl wrote: post #108
tptacek wrote: post #105

Earlier quoted context omitted.

The human rights record of the USA is not reasonably comparable to that of China. 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.

China doesn't have political freedoms, but our incarceration rate is about 7 times higher than theirs; indeed, the USA has the highest incarceration rate in the world: http://en.wikipedia.org/wiki/List_of_countries_by_incarcerat... 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.

I probably agree with the principle behind your comment, but:

* 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.

Re: China prepares to grow vegetables on Mars

#120

Post by qu4z-2 »

stcredzero wrote: post #90
scaphandre wrote: post #70

Earlier quoted context omitted.

You've got it wrong. Mars is further from the sun.

> You've got it wrong. 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.

I don't thing the GP was worried about the amount of sunlight needed to grow food, but rather pointing out that Icarus's downfall was flying too close to the sun.
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