Introduction: Growing Cube With Drawer for Spacecraft - Year-Round Indoor Salad Gardening( Stage III)
This Instructable is an entry to Growing Beyond Earth Maker Contest in Professional Category.
This Instructable is an extension to my Year-Round Indoor Salad Gardening( Stage I) and Year-Round Indoor Salad Gardening( Stage II). It was inspired and brought on by Growing Beyond Earth Maker Contest. So I included both in the title to reflect the background.
I'm not in high school or collegiate but an individual who likes gardening as a hobby. I don't have access to design software or maker tools. I have thought of finding a 50cm cube cardboard box and lining it with waterproof fabric. Then it will be hard to harvest inside a box. Then I walked and searched in many stores until I walked to Sterilite stackable storage drawer which is 17" D x 14" W x 19 3/8" H when two of them stack together. It's waterproof. Astronaut doesn't need to reach down to harvest. The 2.7" space in depth will accommodate a fan for air circulation. The 5.7" space in width will house a water unit for the plants and storage compartment for supplies for future batch of growing. The whole unit is as close to a 50cm cube as a prototype can be (Its dimensions are 50cm D x 50cm W x 49.2cm H). If this prototype will grow vegetables well. I don't think it will be hard to make the drawer unit in spacecraft quality .
Besides the drawer unit, below are all supplies I used. Steps follow that.
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2 Sterilite stackable storage drawers, 17" D x 14" W x 20" together
1 Fabric linen piece, dark color, 57" L x 14" W
Step 1: Make the Growing Cube With Drawer
Again I don't have means to design and make a cube from scratch. I walked and searched in many stores until I walked to Sterilite stackable storage drawer which will be 17" D x 14" W x 19 3/8" H when two of them stack together. That's what I started with. (Photo 1)
First I drew circles on the back side of the drawer where I will make holes (Photo 2, 3 and 4). The front comes with holes. So the holes will promote convection and air circulation inside the drawer.
Second, I used a stencil cutter (photo 5) and made holes at places I just drew (Photo 6).
Third, I taped the sides that don't need to be painted and spray painted the drawers blue (Photo 7, and 8). The drawers were translucent white. Seeds kept in the darkness during the initial incubation period sprout faster. That's why I painted the drawer a deep color.
Step 2: Set Up the Growing Medium
I decided to use 6 layers of all purpose burlap cut to the size of the drawer as growing medium (Photo 1 and 2).
I used 100% cotton twine to loosely keep all layers together at places (Photo 3).
Velcro patches were used at the corners of the drawer (Photo 4) and on the bottom layer of the burlap layers (Photo 5) to keep the growing medium to stay in place. The tiny Velcro patches are the only materials in the growing medium that are not 100% composted.
Then I made the hydroponic nutrients solution according to the instructions (Photo 6, 7, and 8) and saturated the growing medium with the solution (Photo 9).
Step 3: Sprouting
I decided to sprout sunflower because that's what I have on hand and that's what worked well and tasted well before.
To determine how much seeds to sprout, I spread the seeds in the drawer and collected them to sprout (Photo 1).
The night before, I soaked the seeds in tap room temperature water (Photo 2).
When ready to sprout, I rinsed the seeds and spread the seeds on top of the growing medium (Photo 3).
Then loosely cover the seeds with another layer of burlap saturated with hydroponic nutrient solution to keep seeds stay in place (Photo 4).
Again I loosely tied the top layer burlap with the bottom layers using twine with an easy release knot (Photo 5). My hope was the sprouts would poke through the netting of the jute, which did not happen. Thankfully, by untying the easy release knots, the top layer of the burlap was removed easily later. That can be reused in next sprouting batch as growing medium.
To top the sprouting medium with wet towel, I used 100% cotton fabric scraps from sewing projects (Photo 6), cut and pieced the fabric scraps to the size of the drawer (Photo 7), wet the fabric towel with water and place on top of the sprouting medium (Photo 8). Where there is suppression, there is opposition. The wet fabric towel will keep seeds moistened and stay in place and promote them to sprout and push up.
Keep the drawers in the dark and do nothing for 4-6 days depending on the ambient temperature (Photo 9).
Step 4: Install Light
When the seeds sprout and push up the wet towel, they will need light to grow green vegetation.
I bought two plant LED light panels thinking one panel for each drawer. Then I found it would be too close to the plants. The good thing about sprouts is they do not need strong light to grow to big or hard plants. So I decided to remove one drawer and placed it by windowsill which naturally became the placebo growing sample.
Next, I marked the places for 8 holes for the ropes to hang the light panels under the top cover (Photo 1). To make the holes, the stencil cutter came into play again (Photo 2).
Then I measured and cut 4 pieces of cardboard and stitched them together to form the box to replace the drawer that now grew placebo sprouts and slid it in place (Photo 3, 4 and 5).
Next, ropes (100% cotton twine) were attached to each light panel and used to hang the light panels under the top (Photo 6, 7, and 8).
Lastly I pried the top lid of the bottom drawer off (Photo 9) so the light is directly above sprouts, about 13-15" away to begin with (Photo 10 and 11).
Step 5: Install Water Unit
I found slim water dispenser (Photo 1) to hold the hydroponic nutrients water solution for the life time of the sprouts.
To water the sprouts, I inserted one end of 21" latex tubing to the spout and used waterproof silicone seal to keep the tube in place and prevent water leaking. And a pinch cock clamp is used as second water stopping and releasing mechanics (Photo 2, 3, and 4). Now watering the plants once every 24 hours takes less than 10 seconds on the earth in my house. Will it be the same on the spacecraft?
Also under the water unit is a storage compartment which holds pre-cut growing medium and the top covering fabric for future batches (Photo 4, 5, 6, and 7).
Step 6: Add a Fan for Air Circulation
I don't find problem arising from air circulation issue on the earth in my house. In case it is an issue in the spacecraft, a desk fan can be attached to the storage compartment or the side of the cube with a hinge. The fan can blow air through the holes on the front and back sides of the drawer and can be moved out of the way when the drawer needs to be pulled out (Photo 1).
Step 7: Care and Harvesting
The only care is to water the plants once daily which takes less than 10 seconds (Photo 1 and 2). Photo 3 shows the sprouts grown in growth cube drawer, placebo drawer by windowsill and traditional soil sprouts by windowsill from left, to right and to top. Photo 4 shows harvested sprouts grown in growth cube drawer, placebo drawer by windowsill and traditional soil sprouts by windowsill from right to left. The growth cube sprouts have larger leaves but shorter stems compared to the placebo drawer by windowsill and traditional soil sprouts which is not a negative thing. They tasted exactly the same.
Three days before harvesting, spray the sprouts generously daily which functions as washing them. Then one can snip the sprouts with fingers and eat them fresh like that, one at a time or a bunch at a time, perfect to serve on the spacecraft I think.
Now this works on the earth in my house. If you have experience on the spacecraft, please comment and let me know if you think this will work on the spacecraft. I'm very curious about it. Thank you.
Participated in the
Growing Beyond Earth Maker Contest