Previous Blog Posts

Blog 1 - Challenge Overview + Plant Growth Factors

Blog 2 - Plant Growth Chamber Design

Blog 3 - The Project Plan + Prototype Materials

Blog 4 - Automation Using The Challenger Kit

Blog 5 - Enclosure Prototype + Light/Air/Temperature

Blog 6 - Plant Pot System + Assembly

Blog 7 - Enviro HAT Data Collection and Plotting

Blog 8 - Automation HAT Irrigation System

Blog 9 - Wearing Two HATs At Once

 

Reflection

 

This challenge sped by really fast! In this short amount of time, I've learned so much about how Raspberry Pi works. It was truly a pleasure to pick up some engineering skills and to hone in on my astrobotany knowledge. To summarize my design:

 

The Space Salad System successfully addresses the prompt of feeding astronauts on a trip to Mars and its microgravity-compatible design is validated by NASA technical research.

  • The Space Salad System offers three delicious and nutritious meals a day for a crew of two hungry astronauts. This original and refreshing Space Salad theme sparks conversations about not only about growing plants in space, but also identifying flavors that compliment each other and combine to form a truly delicious and nutritious space meal.
  • The innovative staggered growth phase design makes effective use of the 1m3 space allotted and provides astronauts with a generous daily harvest of 5 heads of lettuce, a couple of tomatoes, part of an onion, and a sprig of cilantro.
  • The system is both microgravity and gravity compatible so that it can produce food on the trip to Mars and after landing on Mars.
  • The choice of microgravity-compatible substrate calcined clay is unique spin on traditional soil and hydroponic solutions.
  • The innovative self-watering feature of the plant pot system creates a low-maintenance solution to a traditionally high-maintenance problem of underwatering/overwatering.
  • Small but important details like pollination for tomatoes are seamlessly incorporated into a thoughtful design. The placement of tomatoes on the door of the chamber exposes the tomatoes to vibrations that disperse pollen every time the door is opened for the daily harvest.

 

The prototype demonstrates core functionality and utilizes three components from the Challenger Kit.

  • I successfully grew radish and lettuce to harvest with my plant pot system! Given the short growing season, the slower growing plants (tomato, onion, cilantro) have not yet reached maturity, but are on track to produce sizable harvests.
  • I demonstrated that I can collect relatively accurate temperature, humidity, and light data through Enviro HAT sensors and I implemented a harvesting notification.
  • I implemented an automated irrigation system with the Automation HAT Mini.

 

 

Official Teaser Video

 

 

Future Directions

 

I've learned so much through the first iteration of this project and all throughout, I have been documenting areas for improvement. Of course, my system needs more time until it is outer space ready. For example, the current prototype of my microgravity-compatible plant pot system needs a cover to contain the soil in order to be truly microgravity-compatible. But that's an easy fix with rapid-prototyping tools like 3D printing. For this section, I focus on key concepts and themes rather than particular prototype iterations.

 

Maximize food production, nutritional quality, and flavor through customized lighting.

  • Far red light can enhance yield of leafy greens like lettuce by approximately 30%.
  • Multicolored LEDs can be programmed with specific light recipes per plant variety and desired flavor profile.

 

Save astronaut time by further simplifying the overall design and the maintenance required.

  • Individual plant pot systems can be merged together in order to reduce the number of irrigation tubes/sensors needed to automate watering.
  • The platforms can be automated so that they move up/down like an elevator according to the growth phase of the lettuce. This eliminates the need to manually move the lettuce/platforms as the lettuce plants mature.

 

Cultivate a greater variety of plants in order to expand the diversity of flavor and food groups in space.

  • Spicy is a fundamental flavor that we need to send to space! In fact, NASA is sending chile peppers to space this year. (NASA Kennedy Space Center Technical & Horticultural Scientist Jacob Torres is running the Space Chile Challenge to engage the community and build global awareness around growing plants like chile in space.)
  • Legumes are an excellent source of protein and are under active research by space scientists for its symbiotic relationship with nitrogen-fixing bacteria. (Magnitude.io, an educational astrobotany company, is running legume experiments in space to accelerate legumes as a candidate crop for future space missions.)

 

Acknowledgements

 

I'd like to conclude with a big thank you to element14 for this opportunity, the Raspberry Pi Foundation and Pimoroni for sponsoring the kit, and fellow challengers for this wonderful community. Thank you Back To The Roots for providing me with seeds and NASA Scientist Jacob Torres for engaging the Facebook community in astrobotany and giving me a place to showcase my work. Thank you to all who have been following my blogs and supporting my journey. I had a great learning experience and it's all thanks to you.

 

This being the last blog of the 10 blog series, I don't have have a next blog to intro. So in place of that, I'll leave the audience with some food for thought. The following are a series of thought-provoking conversations I've had through the Space Chile Challenge Facebook group.