Introduction: Staggered Plant Growth in Space
Hi, My name is William DeGroot, and I am a first-year at Amherst College. This Instructable is my Collegiate-level entry into the Growing Beyond Earth Fairchild/NASA contest.
And so without further ado, let's begin by discussing what cookies have to do with extraterrestrial vegetation. . ..
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Step 1: Philosophy of Design
After first discovering this contest, my first move was to visit the Fairchild website in search of some plans/information regarding my competition -- i.e. the existing NASA system. And among the documentation listed in the contest overview, I found a paper with exactly what I was looking for.
The "Veggie" System -- as diagrammed in the first attached picture -- houses 6 plants at one time in two rows of 3. Upon seeing this, my mind immediately drifted to a few nights ago when I was baking some chocolate chip cookies with my siblings and my sister scolded me for not staggering the dough balls on the pan. "It saves space!" she said.
The "Veggie" System, I believe, commits this same waste. Rows and columns are fine organizational tools when the what-you're-organizing is rectilinear, but for all things circular, staggering is far more efficient.
Next, (after committing to a staggered veggie floor-plan), I started to think vertically. Was there a way to use the space that I saved and the micro-gravity that exists beyond Earth's atmosphere to fit even more plants into the 50x50cm cube? I settled upon a two tier design with exactly 8 plants growing upside down (4 on each level). In the "Final Stagger Model" Picture above, the plants growing upside down are marked by 'X's. And keep scrolling to see a cross section. This arrangement is logical (and superior to for instance having all of the plants grow in one direction) because it solves the issue of wasted space under the head of each plant. In this model, the plants fit together like jig-saw puzzle in every dimension. *
In total, the Stagger System can house 22 plants at one time!
*Still, it's worth noting that having some plants grow upward and some downward does complicate matters when installing light sources. This will be discussed later.
Step 2: Materials Needed/Plant Specifics
Given that for this contest, I only wanted to create a relatively basic mockup of my design (as opposed to a commercial-proof, NASA viable, injection-molded machine), I mostly used materials that I had lying around my house. Feel free to substitute supplies as you see fit -- this especially applies to the plastic sheets; they were the remains of an old project I was looking for an excuse to use.
- 6 .75x1.5x20 in. boards (20in roughly equals 50cm)
- 2 .75x1.5x18.5 in. boards
- 1 20x20 in. bendable plastic sheets
- 1 22x20 in. bendable plastic sheets
- 4 2x20 in. bendable plastic sheets
- 4 7x7 in. bendable plastic sheets
- 1 22x20 in. sheet of gopher wire
- lots of small nails (see picture)
- ~2000 sq in. of dirt
- Spool of LED strip lights
- 1 9V Battery
- Soldering Iron
Optional (for 3D Printing):
- Filament + 3D Printer :)
Step 3: Build Frame Part 1
1. The bottom frame is composed of two .75x1.5x20 in. boards lying parallel to each other, connected by two .75x1.5x18.5 in. boards at either end. See pics 1 and 2 for elaboration.
2. Next adhere the 20x20 in. plastic sheet to one side of the frame, using small nails up and down the sides.
3. Attach the other four .75x1.5x20 in. boards to the frame. Four boards for four corners. See pics for detail on precisely where they should be attached.
Step 4: Build Frame Part 2
1. Use the four 2x20 in. plastic sheet to line each of the four sides on the bottom level. Hammer in nails as you see most fit. See pics for what I found to be easiest/most effective.
Step 5: Add Second Level
1. Measure and mark 9 inches up on each of the four vertical frame boards.
2. Use nails to secure the 22x20 in. plastic sheet in place, 9 inches up. (Again, see pics).
3. On each of the four boards, on each inner-facing side, pound in a nail about half way. With a hammer, bend each nail slightly upwards.
4. Hang the 22x20 in. sheet of gopher wire on these four nails. See pics for clarification.
Congrats! You're done with the essential frame!
Step 6: Make Curtains
1. Wrap each of the four 7x7 in. plastic squares with duct tape. Maybe do a double layer. It's important that light is unable to pass through!
Step 7: Fill With Dirt + Install Curtains
1. Fill both the first and second tiers with approximately 3 inches of dirt. See pics for specification.
2. Cut out 7 6cm radius holes in the 2nd layer of plastic in accordance with the layout specified in step 2.
2. On the lower level, place each curtain at a different corner. These curtains will allow for the plants growing downward to follow their own light sources!
And this is essentially the most basic model! You're done!*
*You may note that no electronic components are connected yet. I will revisit why this is after delving into the 3D modeling aspect of this project.
Step 8: 3D Model
I wanted to create a 3D model of my design to solidify my concept and to reserve the ability to virtually make changes to my design in response to prototype failures. Screenshots of my finished model in addition to a time lapse of the 3D design process can be found above. The files are also available for download.
Step 9: 3D Printing the Modular Pieces
The entire model prints in 3 separate parts -- the frame and the upper two levels. Also, from the pictures, you may notice that the frame is slightly cracked. This occurred because I did not sand down the frame before trying to slide the shelves onto it. I think that, had I taken the time to sand off the excess filament on each of the upwardly protruding rectangles, this would not have been an issue.
Other than that, the print turned out great!
Step 10: Implementation + Future Steps
At this point, I want to acknowledge what future steps I need to take in order for this project to be a fully working, microgravity-proof design.
Firstly, I still need install a light source. However, I do know exactly what I am going to do on this front. Once I'm able to get my hands on some LED Strips, it will be very easy to simply attach a strip to the bottom of each of the four curtains. And then more strips will be situated on the outside of the curtains for the rest of the plants.
Next, as of right now, my prototype does have the third tier as displayed in my 3D model and 3D printed prototype. This third tier would, in a final design, primarily serve as both electronics housing and the the area with dirt for the second level of upside-down growing plants. I am waiting to finish this until I have some electronics to outfit it with.
I'm aware of the imperfections of this project. The prototype is not perfect, and the design will surely need future tweaking. I should also say that I'm aware that this design is not at all automated. And admittedly, a timed watering/lighting system would definitely make things easier for the astronauts using the system. Still, I don't think any of this negates my efforts here; my aim was simply to provide a unique, conceptual model for spatial arrangement: the Stagger System.
Thanks for reading, and make sure to vote! :)
Participated in the
Growing Beyond Earth Maker Contest