5 Sided Cube
This is an entry for the professional category in the contest “Growing Beyond Earth”.
My entry seeks to help solve the problem of space not being used efficiently in the current 50cm gardening experiment cubes.
In the current setup one side of a six sided cube is used for growing plants. My idea is to use 5 sides of the cube for growing plants. The remaining side can house the light for the plants as well as any support systems for the plants.
Light could be provided by a fiber optic array. This array would radiate light from the center of the cube evenly illuminating all 5 sides. Ideally light could be gathered from out side the space craft and moved via fiber optics into the space garden. This is probably not possible at the current time so a full spectrum LED light could be used to generate the light instead. Small flexible fiber optic lines with small light diffusers on their ends could be used to get light past the top leaves of plants. And since they are flexible, they hopefully would not get too much in the way of maintenance and harvesting.
In my 5 sided cube design water could be delivered to the growth medium via a hose system with 1 way valves. A hose could run under or through each of the 5 sides with growth medium. The hose would have a bunch of small one way valves in it. Water could be added to the irrigation system under pressure and would evenly irrigate the growth medium. I have heard that there are problems with water not wicking correctly in zero g. Perhaps after pushing water into the growth medium air could be pushed in through the same hose. This would expose the roots to both water and air, keeping them alive. A syringe could be used to add water or air to the irrigation system.
One problem with this design is that the plants are limited in how high they can grow. A possible solution is to choose plant species carefully. We could choose a species that matures at a fairly low height and ideally can be partially harvested and keep growing. A species of mint might be a good candidate. I bet the astronauts would appreciate some mint to chew on :).
It's interesting thinking about gardening in space. It’s comforting to think we might take a little piece of home with us whenever we head out into the cosmos.