Nuclear Powered LEDs For Space Farming 287
DevotedSkeptic writes with an interesting article on possible lighting sources for growing food on the moon and other off-world locations. From the article: "... Agriculture remains the key to living and working off-world. All the mineral ore in the solar system can't replace the fact that for extended periods on the Moon or Mars, future off-worlders will need bio-regenerative systems in order to prosper. Here on earth, researchers still debate how best to make those possible, but nuclear-powered state of the art LED technology is arguably what will drive photosynthesis so necessary to provide both food and oxygen for future lunar colonists. ... Although during the two weeks that make up the long lunar day astronauts might be able to funnel refracted sunlight into covered greenhouses or subsurface lava tunnels, they will be left without a light source during the long lunar night. Current solar-powered battery storage technology isn't adequate to sustain artificial light sources for two weeks at the time. Thus, the most practical solution is simply to use some sort of Radioisotope Thermoelectric Generator, not unlike the one powering the current Mars Science lab, to power the LEDs that will spur photosynthesis in lunar greenhouses. ... On earth, Mitchell says it takes roughly 50 square meters of agriculture to provide both food and oxygen life to support one human. But, as he points out, who can say how productive plants are ultimately going to be on the moon, in gravity that is only one sixth that of earth?"
Lots of useful information in there... (Score:5, Interesting)
First, I've never heard the 50 sq meters (538 sqft) to sustain 1 human before. It's about the same area as an ultra-efficiency apartment. I assume that's for high-efficiency hydroponics. Interesting. I wonder if it'd be possible to grow some sort of edible algae to suppliment the more traditional crops? IE have an intense 2 week growing season, harvest when the sun goes down, then reseed when it comes back up? That would reduce the need to use your nuclear generator to keep the plants alive/in the proper growing cycle.
The gravity might mean you needing a slightly different breed, but given what I've seen with hydroponics/areoponics, I doubt that 1/6th gravity will have that much of a negative effect - but that would be something for the ISS to figure out!
Re:We should know this already... (Score:4, Interesting)
Exactly! (Score:5, Interesting)
Exactly! We should be setting up a farm on the moon. Just to test it out. Start small: 1 m2 of soil in a greenhouse.
The cost of such a mission is for a small part related to the cost of the boosters to get things in orbit and to the moon, and for a large part to the over-engineering that NASA is doing. That over-engineering is caused by a fear of failure. It's not like it's rocketscience to get anything to the moon. The fear of failure is the only thing that seems to hold us back.
If it costs 5000 $/kg to launch anything into a high orbit (which I will equate with getting it to the moon), a decent sized farm (1000 tons of material) would cost 5 billion $ in launch costs, which is nothing.
We could set up some practice greenhouses for a fraction of the cost. If failure is an option, that should be cheap enough in an age when more than that is spent on warfare every day...
The problem is power.... (Score:4, Interesting)
This is all about the moon's 14-day, Lunar–night power famine. The solution is simply to use solar power satellites [wikipedia.org] sitting at one of the Earth-Moon Lagrangian points, where the solar collectors will be in perpetual sunlight. Perpetual power means always-on growing lights so the problem is solved without the need for RTGs, and their pretty horrible thermal inefficiency (not to mention the problem of where do you get all that Pu239 from).
The main problem with using solar power satellites for supplying power to the Earth (the huge cost of launching them into space) is neatly inverted in the Lunar context as, by placing a solar colony's power hardware in space, you have a large mass of hardware that doesn't have to be soft-landed on the moon, representing a substantial saving.
Re:We should know this already... (Score:4, Interesting)
Then you can actually have people, animals, plants etc living AND reproducing in space as opposed to trying not to degenerate so fast.
Trying to settle on the Moon and Mars without such stuff is like trying to jump before even being able to stand.
So from my perspective NASA etc nowadays are mainly a waste of resources. They're not really working on the necessary steps for the long term survival of the species in space. They're just sending expensive toys to mars and other places.
p.s. fish would probably do ok in low gravity, and some live on algae which doesn't need very much. You're going to want to have tons of water around anyway, so might as well put fish in at least some of it and filter the water when you want to use it for other stuff.