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I don't think we should assume LEDs for lighting. High quality optical fiber can transfer sunlight with a degrading rate of 10%/km [0]. Light can be farmed on

by max76 8y ago

I don't think we should assume LEDs for lighting. High quality optical fiber can transfer sunlight with a degrading rate of 10%/km [0]. Light can be farmed on the surface from a larger surface area that it will be projected onto in the farm. Is the sunlight on mars incapable of growing plants? This process would remove the need of generating 2MW of electricity. [0] https://computer.howstuffworks.com/fiber-optic2.htm https://computer.howstuffworks.com/fiber-optic2.htm

jaggederest 8y ago
This came up last discussion. It's actually easier on mars to do completely artificial lighting than concentrate, since the concentrators need to be about 3-4 times larger in area than the farmland would be on Earth, and are thus extremely bulky. Unless you can produce optical quality mirrors in-situ, it's probably easier to ship LED arrays.
- mLuby 8y ago
  Plus you don't have to clean the dust off your reflectors if you've just got a whole self-contained system underground.
- lxmorj 8y ago
  With LEDs you can focus your output on photosynthesis-friendly wavelengths and collect in a wider spectrum, no?
politician 8y ago
Agreed; these guys [1] are developing concentrated solar for a lunar regolith melting application. And the high-quality fiber can be made in orbit [2]... [1] https://www.lpi.usra.edu/meetings/leagilewg2008/presentations/oct29pm/Nakamura4011.pdf https://www.lpi.usra.edu/meetings/leagilewg2008/presentation... [2] https://www.iss-casis.org/blog/taking-zblan-optical-fiber-production-to-space/ https://www.iss-casis.org/blog/taking-zblan-optical-fiber-pr...
- gotocake 8y ago
  The Moon is a lot closer to the Sun than Mars, and you have to remember that EM radiation falls off with the square of the distance. Mars is unsuitable if you need to rely on solar power alone, especially for concentrating and piping light to grow crops.
aunty_helen 8y ago
Whilst using fiber optics to transport the light is a nifty idea, like you mentioned, you have to 'farm' the light on the surface. So that means bringing collectors, making them sturdy enough for the winds and then also going 'outside' to clean them. Might be easier to bring LEDs and something nuclear that also provides a lot of waste heat you can use. However, if you did user fiber you end up with a light source that's there about half of the time, but plants can grow better with more sunlight. I'm no expert on hydro/LED factory farming so I'll stop there but I'm sure anyone who has grown cannabis would be able to tell you of the advantages to a light source that's highly configurable.

by max76 8y ago

jaggederest 8y ago

This came up last discussion. It's actually easier on mars to do completely artificial lighting than concentrate, since the concentrators need to be about 3-4 times larger in area than the farmland would be on Earth, and are thus extremely bulky. Unless you can produce optical quality mirrors in-situ, it's probably easier to ship LED arrays.

mLuby 8y ago
Plus you don't have to clean the dust off your reflectors if you've just got a whole self-contained system underground.
lxmorj 8y ago
With LEDs you can focus your output on photosynthesis-friendly wavelengths and collect in a wider spectrum, no?

politician 8y ago

Agreed; these guys [1] are developing concentrated solar for a lunar regolith melting application. And the high-quality fiber can be made in orbit [2]... [1] https://www.lpi.usra.edu/meetings/leagilewg2008/presentations/oct29pm/Nakamura4011.pdf https://www.lpi.usra.edu/meetings/leagilewg2008/presentation... [2] https://www.iss-casis.org/blog/taking-zblan-optical-fiber-production-to-space/ https://www.iss-casis.org/blog/taking-zblan-optical-fiber-pr...

gotocake 8y ago
The Moon is a lot closer to the Sun than Mars, and you have to remember that EM radiation falls off with the square of the distance. Mars is unsuitable if you need to rely on solar power alone, especially for concentrating and piping light to grow crops.

aunty_helen 8y ago

Whilst using fiber optics to transport the light is a nifty idea, like you mentioned, you have to 'farm' the light on the surface. So that means bringing collectors, making them sturdy enough for the winds and then also going 'outside' to clean them. Might be easier to bring LEDs and something nuclear that also provides a lot of waste heat you can use. However, if you did user fiber you end up with a light source that's there about half of the time, but plants can grow better with more sunlight. I'm no expert on hydro/LED factory farming so I'll stop there but I'm sure anyone who has grown cannabis would be able to tell you of the advantages to a light source that's highly configurable.