PaigeAndJoe

Houston, TX | Have seeds will travel!

Paper and Fog

High-Level Project Summary

Growing food on a spacecraft, or in a small home in northern Canada or Alaska, has several specific challenges: Spacecraft: weight of growing modules, space before deployed - Northern Earth: mainly cost since people who need this are generally not rich- Both - power requirement, lack of sun, lack of soil, lack of growing space, sharing living space with planting space, etc. To solve many of these issues at once, I propose two things, using fogponics, rather than hydroponics - better growth, lower power, less prone to clogging, - and the humble paper as a planting module building material - cheap, sturdy, light, thin, packs flat. Also proposed a triangular design to optimize space usage.

Link to Project "Demo"

https://app.box.com/s/9a6eopgo8rc4hquqi0dhnd1gpjz5jq6m

Detailed Project Description

The current state of the art for growing food in space is the Veggie module. Pros - It works, has fed actual astronauts in space, easy to deploy, low maintenance, compact stow profile, low power usage, plants are visible to crew, although behind fuzzy plastic and in weird light. Cons - It's a square module in a curved ISS. All spacecraft have curved walls, so big squares are not ideal uses of space. It's intended as an experiment, not a full scale food source. One salad a week is not going to keep body and soul together for a crew. The plants are isolated from the people, and only even visible via non-white light.

Sometimes food is just a bonus. People go to a huge amount of trouble to have plants, from me turning our rock and cactus Texas hill into a garden, to an office worker putting a potted spider plant on his desk, humans are fundamentally happier with plants. And long space journeys can be hard on the human psyche.

The psychological benefits of having plants in your living space are huge, especially when spending long periods of time in space. When the people and plants are separated, and the plants don't even look the way humans are accustomed to them looking, many of the psychological benefits are lost.

Considering the pros and cons, my husband and I searched for a way to improve on the concept, while having the plant in the same space as the people. I am an avid gardener and dabble with indoor growing, mostly sprouts, but I bought the equipment to do microgreens, and some of the equipment for fogponics a while ago, although I haven't had a chance to put them to use. My husband is a maker, with skill in a ton of different materials. He also has nearly every tool known. Between us, we did a lot of brainstorming.

One concept we considered was that all spacecraft, ISS, and the Orion, have curved walls. We wanted to build grow modules that attached to the walls, with the water component outward and the plant inward toward the people. Advantage of water element toward wall is some degree of radiation shielding added for inhabitants, and advantages of plant inward: psychological, oxygen supplementation, no need to provide air for plant as it uses air provided for people. We considered hexagons and octagons, but triangles are simple, strong structures, and provide a lot of flexibility for curving around.

Fogponics provides smaller particles of water, with nutrients carried along, for plant roots. Plants in several studies are shown to grow better with those smaller particles. Also, fog emitters are very quiet, durable, and low power requirement. A timer to turn them on and off is required, but they are far less problematic than high pressure hydroponic systems.

Additionally, the addition of lightweight mylar mirrors on top, provide a way to close the top for when seeds are germinating and need darkness, and when open amplify the light provided to the plant, making less light necessary for good growth, and reducing power requirement.

I also thought it would be a good idea to have red, blue, AND green LEDs to provide simulated white light, and reflect it back into the main cabin with the people. This provides general light for functioning, and removes the need for other cabin lighting. It also allows people to enjoy the plants in natural lighting conditions.

We also considered a porous cloth made of polypropylene as an envelope that seeds could be placed inside. This top part of the module would need major work to recycle or clean. The rest should require a simple rinse with bleach water or similar sterilizing fluid to make it ready to go again.

Another concept is that many plants can be consumed at different life stages. Peas can be eaten and many stages as demonstrated below, increasing dietary variety, with limited number of crops. When the final stage is complete, some peas can be saved and planted to begin again. This reduces the amount of seeds necessary to take with the crew on long voyages.

Several plants have a similar cycle of edibility at different stages. Also, plants like turnips provide different foods with different flavors, textures, and vitamin profiles. A turnip root is very little like turnip greens.

The main planting module is about 4 inches thick and about 8 inches on a side, but special stackable modules and plant nets, supported by the adjustable lights would provide versatility.

Finally, we realized after considering multiple possibilities for materials that paper might be the least expensive, the most light weight and sturdy. Whether corrugated, or simply card stock with a waterproof coating, paper is remarkably sturdy.

Space Agency Data

https://www.nasa.gov/sites/default/files/atoms/files/veggie_fact_sheet_508.pdf

https://www.nasa.gov/content/growing-plants-in-space

https://www.nasa.gov/sites/default/files/atoms/files/advanced-plant-habitat.pdf

Hackathon Journey

I am an avid gardener and dabble with indoor growing, mostly sprouts, but I bought the equipment to do microgreens, and some of the equipment for fogponics a while ago, although I haven't had a chance to put them to use. My husband is a maker, with skill in a ton of different materials. He also has nearly every tool known. Between us, we did a lot of brainstorming.

And a fair amount of research, including on Veggie, which I found here: https://www.nasa.gov/sites/default/files/atoms/files/veggie_fact_sheet_508.pdf

My husband's father is in the hospital for cancer surgery, so we drove a bunch one day, so didn't get to work on the prototype until evening Saturday. Sunday, my father-in-law got released, and my husband left to pick him up and bring him home. So, I was on my own for a lot of the challenge.

References