Inverting the ground and sunlight: What if sunlight didn't beam down? What if plants grew out, inwards?

Hello! This is my submission for the Growing Beyond Earth (college category) submission.

The challenge given was that in space "as plants grow, leaf surfaces become closer to the light, creating empty space underneath." I took a creative approach and tried to imagine what it might look like to design a system that minimizes empty space as the plants grow given that there "is no up or down in microgravity, but plants will grow towards the light."

Constraints:

Due to microgravity, water doesn’t necessarily drip down, it needs to be precisely administered
Fit inside 50 cm^2
Light needs to shine on all plants
Optimize temperature
Harvesting and maintenance of the plants needs to be easily accessible
Intuitive monitoring

My MRI scanner-looking solution explores what it might look like if we switched the places of sunlight and the ground. Instead of sunlight beaming down, it beams outwards, shining light equally on a ring of plants growing on the interior face of a cylindrical container. Due to the microgravity environment, as the plants grow, they grow towards the center, not outwards. In application, testing would need to determine the proper spacing of the plants from each other and what types of plants would grow towards the center without blocking too much light from the other plants.

Supplies

Cylindrical Container
Irrigation tubes
Soil moisture sensor
LED light rod
Interactive display monitor
Fan
Seed packet
Transparent plastic lid
Soil

Step 1: Step 1: the Casing + Irrigation

Casing: The casing (left) is configured like a hexagon nut. The circular interior enables light to shine on all plants equally while the hexagonal exterior allows for the device to rest on a face.

Irrigation: The pressurized irrigation tubes are embedded within the casing to precisely administer water to areas soil moisture sensors deem is too dry; however, gardening can provide therapeutic effects to astronauts by providing an interactive form of entertainment, so it is also possible to open the container lid and water the plants manually.

Step 2: Step 2: LED, Fan, and Cap

Fan: On one side of the container is a fan that maintains cooling (left image). The fan pushes air from one side of the container to the other out through the translucent lid's ventilation holes (right image). The lid/cap is translucent in order to view the progress of the growing plants.

Light: Protruding from the fan is an LED that mimics the sun's light while maintaining energy efficiency. Different colored LEDs can be used depending on the type of plants needed to grow as some studies have found correlations between food taste and the color LED used to grow the plant.

Step 3: Step 3: the Seeds

Given that there is no up or down in microgravity, the seeds can be placed along the inside of the circular soil as long as they are oriented with the sprouting end facing towards the center of the soil ring. The proximity of the seeds planted to each other depends on how large the type of plant is expected to be when it grows.

Step 4: Step 4: Monitoring Display Interface

View light, water, heat, and pH levels on an interactive display. The dot represents the current level. To the left of the dot represents the measurement history and to the right of the dot represents what the system is planning to do. Change the amount of water/light/height/pH by dragging the lines to the right of the dot accordingly.

The number of days since the plants have been planted is displayed as well as the number of days left until the plant is ripe for harvesting.

Changing light: controls the brightness of the light

Changing water: administers more or less water

Changing heat: speeds up or slows down the fan or heat from the light

Changing pH: administers small doses of dolomitic limestone through the irrigation channels to neutralize acid

Step 5: Step 5: Wait and Grow!

Once seeds are planted, monitor their progress using the interactive display and enjoy the harvest! 🥬

Thanks for reading!