High School Entry

With more imminent NASA missions on the horizon, going further distances and longer time periods, it is necessary for a method of self sustenance. Aboard spacecraft, the ability to restock is both expensive and wasteful. As such, our group's participation in this challenge is to contribute a viable method to most efficiently use space to grow plants. One thing that was immediately noticeable to the current design is the limited use of space. Currently, the grow box aboard the ISS uses only one axis of growth, which is directly upwards, as a normal grow box would under gravity.

When creating this project, there were two main concerns, how to best optimize space and limit material that may compromise safety aboard the vessel, such as water leakage. Our group of three researched and came up with the current design for our prototype.

Additional Information

- Within 50 cm^3 parameter

- Flat spinach

Supplies

Materials

Box material - Acrylic sheet (0.2 cm thickness)

Piping - PVC pipe (4 inch diameter and 3/4 inch diameter pipes)

Electronics - Adafruit Metro M4

Lights - LED strips

Tubing - Latex rubber tubing (1/4 inch diameter)

Sponge - Polyurethane sponge

Sprinkler Nozzle - Micro sprayers

Pump

Power supply

Tools

The tools used for this project can vary, as long as the general function is met.
- Drill

- Tape Measure

- Saw

- PVC cutter

*For accurate smooth sides of the cube, we used a laser cutter to cut the acrylic

Step 1: Preparation and Brainstorming

To begin, our group started with the basic element of aeroponics/hydroponics. We discarded hydroponics because of the potential root rot that may occur from continuous root exposure to water. However, we had to analyze how to use a small space to create an aeroponics system that would not compromise the shuttle/station with water. We determined a two layer system to prevent water loss. This is using the larger diameter PVC pipe to contain the roots of the plant, and a smaller diameter PVC pipe inside with misters/micro sprayers to provide the water.

We then moved on to maximizing plant growth. We determined that a cylindrical design would best fit the criterion because it would allow for maximum utilization of the 3D space. After this, we made several paper sketches and rough 3D designs to ensure a surefire plan.

After this, we gathered our materials. We chose acrylic for a number of reasons. First, its see-through property is valuable for observations and it allows manual checkup on the plant and system. Second, unlike glass, it weighs much less and is more durable. Third, there is no chance of degradation over time with the exception of potential scratches. We chose acrylic over materials such as metal or glass, for the above reasons.

After acquiring all of the necessary parts, we took measurements, and drew lines to segment the various materials into the sizes we needed.

Step 2: Cutting and Assembling

The acrylic and the PVC were cut into segments all less than 50 centimeters to ensure it would fit within the parameters (the measurements can be scaled, so capping the size at 50 centimeters was not necessary. After cutting the acrylic into the squares, we assembled them into the cube form.

The cube is held together using braces and one side has hinges for easy access to the plants, but is secured by a latch. Because this is a mockup/prototype, we did not create an airtight box (but the final product would most likely be airtight).

We added the water source, which used storage similar to IV bags. The Adafruit Metro M4 was programmed to automatically activate the pump on regular time intervals (the optimal time interval requires further testing and data collection).

After installing the pump and Metro M4, we completed our prototype.

Step 3: Next Steps

For this prototype, more testing of the general water system is needed before making it a "final product." Some aspects of our project were incomplete by the time of the deadline, such as the electrical wiring of the lights and the piping systems. However, given more time, we are confident that our design will be able to grow plants in a efficient manner in space.

Of course, we thank NASA for this opportunity to step outside our normal boundaries and try new projects, as well as the concept. We hope to improve our design past this competition and into a fully functioning product.