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Thread: Growing plants in deep space

  1. #1
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    Growing plants in deep space

    How far from the sun can plants be grown in sunlight without big mirrors to concentrate the light?

  2. #2
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    Some plants can be grown under normal indoor lighting. Direct sunlight reaches 100000 lux, while a reasonable value for indoor lighting is 50 lux. So, probably out to around 50 AU.

    They're still subject to conservation of energy, of course...plants might survive at 50 AU, but they aren't going to be all that productive.

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    Of course, if they "waste" a lot of energy maybe they could be genetically engineered?

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    To grow decent productive fruiting vegetables they need at least 5-6 hours of direct sunlight here on Earth. 8-10 hours is even better. Leafy veggies like lettuce, spinach, etc can be grown with less.

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    So for fruits you're mostly limited to mars at best?

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    Quote Originally Posted by Tom Mazanec View Post
    How far from the sun can plants be grown in sunlight without big mirrors to concentrate the light?
    What's wrong with grow lights? All you need is power. Why do you need natural sunlight?
    At night the stars put on a show for free (Carole King)

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  7. #7
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    Quote Originally Posted by Tom Mazanec View Post
    Of course, if they "waste" a lot of energy maybe they could be genetically engineered?
    It's not so much wasting energy, as it is that there is a huge difference between the amount of light needed to keep some shade-tolerant plants alive, and the amount of light needed to add biomass and reproduce.

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    So for fruits you're mostly limited to mars at best?
    I can't claim that, by fruiting plants I meant plants that produce vegetables via blossoms like tomatoes, squash, peppers, etc. Potatoes might do well there (nyuk).

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    Hmmm. How far out was Bruce Dern in Silent Running?
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

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    Quote Originally Posted by Trebuchet View Post
    Hmmm. How far out was Bruce Dern in Silent Running?
    Saturn
    At night the stars put on a show for free (Carole King)

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  11. #11
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    Quote Originally Posted by Tom Mazanec View Post
    So for fruits you're mostly limited to mars at best?
    As Swift said, what's wrong with grow lights? I've got a hydroponic garden growing basil that isn't even near a window.

    On Mars, it might be cheap and easy to set out some self-contained low pressure greenhouses because the ground is there to place them on. In orbit, you're building something a little more substantial anyway, so why limit yourself to un-concentrated natural light?

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    Quote Originally Posted by cjameshuff View Post
    As Swift said, what's wrong with grow lights? I've got a hydroponic garden growing basil that isn't even near a window.

    On Mars, it might be cheap and easy to set out some self-contained low pressure greenhouses because the ground is there to place them on. In orbit, you're building something a little more substantial anyway, so why limit yourself to un-concentrated natural light?
    Agreed. Even on the moon with two weeks of darkness, plants will need an artificial source of light.

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