Gr0G - 02 - Why aeroponics?

Here is a list of the posts in this challenge

Gr0G - 01 - Introduction

Gr0G - 02 - Why aeroponics?

Gr0G - 03 - High-pressure system design

Gr0G - 04 - Mechanical design

Gr0G - 05 - Electrical design

Gr0G - 06 - Building the box

Gr0G - 07 - Playing with the Gertbot

Gr0G - 08 - Installing LEDs

Gr0G - 09 - The control board

Gr0G - 10 - Software design

Gr0G - 11 - Building the box (2)

Gr0G - 12 - Building the high-pressure system

Gr0G - 13 - Building the high-pressure system (2)

Gr0G - 14 - Piping

Gr0G - 15 - Improvements

Gr0G - 16 - Remote UI

Gr0G - 17 - Remote UI (2)

Gr0G - 18 - Conclusions

Source code available at https://github.com/ambrogio-galbusera/gr0g, https://github.com/ambrogio-galbusera/gr0g-ble-android and https://github.com/ambrogio-galbusera/gr0g-ble

This challenge focuses on creating something that can grow food both on Mars (or any other planet) and during the travel.

Yielding on a planet (well, I mean... yielding with gravity) is a well-known topic, but what happens to plants on a starship?

When plants are exposed to microgravity, they are exposed to stresses that lead to diseases and poor crops. NASA has performed many experiments aboard of ISS with the Veggie and Advanced Plant Habitat projects. With the data collected with these and many other experiments, the conclusion that has been drawn is that the adaptability of aeroponic process makes its application to spaceflight plant growth systems appealing

According to J.M. Clawson, A. Hoehn, L.S. Stodieck and P. Todd, Aeroponics for spaceflight plant growth:

1. Aeroponic technology can apply individual dosages of various treatments to the plant’s root zone. Growth enhancers, and/or disinfectants can be individually applied to the roots systems in a onetime, multiple-time, and/or intermittent application. The additive-containing effluent can either be recirculated or diverted. If diverted, the effluent can be discarded or retained for use in subsequent treatments. Application of additives with other nutrient delivery technologies can be more problematic. In hydroponics, for example, a complete system volume of nutrient solution would require purging if additives are to be applied into solution and later rinsed away.
2. Aeroponics can limit disease transmission since plant-to-plant contact is reduced and each spray pulse can be sterile. In the case of soil, aggregate, or other media, disease can spread throughout the growth media, infecting many plants. In most greenhouses these solid media require sterilization after each crop and, in many cases, they are simply discarded and replaced with fresh, certified sterile media.
3. A distinct advantage of aeroponic technology is that if a particular plant does become diseased, it can be quickly removed from the plant support structure without disrupting or infecting the other plants. As an additional safeguard, the aeroponic chamber can easily be cleaned if unsanitary conditions occur by injection of dilute amounts of disinfectants. The disinfectant effluent can be diverted after application so that continual recirculation of it does not impact plant performance.
4. Plant growth performance is still of primary importance to both commercial growers and advanced life support practitioners alike. Studies demonstrated that aeroponics compares favorably in lettuce production per square meter of planting area to that reported in the advanced life support literature

Furthermore, other growth systems proved to have many disadvantages

1. Issues with soil, for example, include improper root aeration
2. Soil and hydroponic systems are both prone to disease propagation

For the above-mentioned reasons, the goal of the Gr0G project is to implement an high-pressure aeroponic system that creates a mist with an average droplet size of 5 to 50 micrometer, which was found by NASA to be the optimal size for aeroponic systems