Greenhouse

Why Do We Need a Lunar Greenhouse?

The Lunar Greenhouse is essential for sustaining life in a long-term lunar habitat. This addition will provide a way to produce oxygen with plants as humans cannot exist without oxygen and the vegetation will aid in managing CO2 levels as well. This will also allow humans to have access to food such as fruits and vegetables, which are quite necessary for human survival. Fruits and vegetables are known to help prevent disease, digestive health, mental functions, and the overall longevity of human life. This greenhouse will also be useful for future research within the agricultural field. Moreover, this segment of the lunar habitat will foster agricultural research, further reducing the need for frequent resupply missions and enhancing the self-sufficiency of the lunar base.

What Does the Greenhouse Inlcude?

Aeroponic Systems

An aeroponic system is an advanced irrigation method that includes water with a nutrient solution that is pumped and then sprayed onto the roots of the plants in specific periods.

Droplet Size and Mist Frequency

This method is superior when it comes to water use efficiency, seasonal independence, less time and space required, and large-scale plant production. Studies have shown that mist droplet sizes above 100 micrometers restrict oxygen oxygen availability to the roots which prevents proper development of the root hairs. On the other hand, drop sizes less than about 15 micrometers would result in too many root hairs and an underdeveloped lateral root system. The misting interval for this process is usually 5 seconds and the timer for these periods is typically every 5 minutes. These values tend to vary a bit when

attempting to produce the most efficient growth rate for different types of plants. However, these given measurements can be accepted for most plants that we are interested in like vegetables. It has also been observed that the required range of temperature for ideal growth is 25 - 30 C along with a humidity level above 60%. When growing fruit trees, we will need to consider applying different droplet sizes, mist frequencies, ambient temperatures, and humidity levels.

Aeroponics vs. Hydroponics and Soil Based

NASA and other space agencies have been experimenting with various forms of hydroponics and aeroponics on the International Space Station as these methods have shown to be quite useful for many different space mission challenges. Aeroponic and hydroponic irrigation systems have both proved to be suitable solutions for efficiency and rapid growth rate needs.

While both methods help limit the required resources, aeroponics tend to require less water than hydroponics. Hydroponics still involves water conservation as it uses a closed water system that recycles the water, which makes it more efficient than soil-based methods. In addition, aeroponics and hydroponics are also viable solutions to the challenges of microgravity. On the contrary, these systems can be quite complex and could be vulnerable to system failures. The aeroponics method requires the use of sensors, pumps, nozzles, and proper monitoring. Any kind of system failure could lead to the roots drying effectively killing plants.

Moreover, soil-based is not completely useless for our lunar greenhouse since this method is extremely simple and familiar to traditional farming practices. Soil also has a natural buffering capacity so that the soil can resist changes in its pH level, despite the addition of acidic or alkaline substances. This is important since the pH of the soil is directly related to the health of the plant. It is also theoretically possible to create a sustainable cycle of soil fertility using human feces, soil, and a variety of organisms such as insects and bacteria. This would involve setting up a closed-loop ecological system which would be similar in concept to a terrestrial ecosystem but adapted for lunar conditions.

Overall, it would be wise to include all 3 of these methods in a fashion that would maximize the benefits of each method and allow us to not completely rely on one system.

Aeroponics

Pros:

Resrouce Effeceincy
Fast Growth Rates
Saving Space
Reduced Disease and Pesks

Cons:

System Complxity
System Failure Consequences

Hydroponics

Pros:

Effective Nutrient Delivery
Water Conseveration
Suitable for Microgravity

Cons:

System Complexity
Potential for Nutrient Imbalnces

Soil Based

Pros:

Simplicity
Familiarity
Buffering Capacity

Cons:

Resource Intensive
Lower Efficiency

Oxygen Production

Humans need food and vitamins to survive long-term, but more importantly, require oxygen to breathe. Plants use the process of photosynthesis to absorb light and use its energy to split water molecules into hydrogen and oxygen. Studies have shown that a single leaf produces 5 mL of oxygen per hour and that whole-body oxygen consumption in normal conditions is about 198 +/- 28 ml per minute. We can use the measured values to get an estimate of how many leaves/plants we will need to keep one human alive.

We can easily calculate that the number of leaves needed = (oxygen needed per hr)/(oxygen production per leaf) = (198 * 60)/(5) = 2376 leaves. This value can also be used to calculate an idea of how many plants we will need considering different plants have different numbers of leaves. Number of plants = (number of leaves)/(number of leaves per plant). However, there are many conditions to consider when assessing how many plants a human will need to survive including the amount of light, water, temperature, and humanity. With the use of different plants and a constant light source, we can at least say that this number will lie in the range of 100-500 plants per person.

Aloe Vera:

It could be beneficial to use aloe vera and a sansevieria plant to help produce oxygen within the lunar base. Aloe Vera is a good option because, unlike other plants that require sunlight to produce oxygen because of the photosynthesis process, aloe vera retains the ability to produce oxygen without it. It will produce less typically, but still be able to produce it. While this is a great benefit, aloe vera provides many other health benefits that it could be used for. Beyond its typical uses like treating sunburns, it can be used for a range of other applications including ingesting it. It contains many vital vitamins, and can be used to treat wounds, infections, and is known for anti-inflammatory properties.

Sansevieria is another good addition to the oxygen-producing plant life on the base as it is known to be anti-fever and anti-pain, but has also been found to be a very good air-purifying plant according to some research. The plant is more commonly known as a snake plant and has several benefits that could go a long way in creating a livable atmosphere in the lunar base.

Neen

Another great option to consider is Neem. Neem has many healing properties as well as being a plant that helps purify air and produce oxygen. The effects are outlined in the chart below taken from the National Library of Medicine, National Center of Biotechnology Information.

Discussion

Feasablity

Summary

Sources

Admin. (2017, January 26). Hydroponic Systems. Center for Agriculture, Food, and the Environment. https://ag.umass.edu/greenhouse-floriculture/fact-sheets/hydroponic-systems

(PDF) Aeroponics: A review on modern agriculture technology. (n.d.). https://www.researchgate.net/publication/342804239_Aeroponics_A_Review_on_Modern_Agriculture_Technology

Tunio, M. H., Gao, J., Qureshi, W. A., Sheikh, S. A., Chen, J., Chandio, F. A., Lakhiar, I. A., & Solangi, K. A. (n.d.). Effects of droplet size and spray interval on root-to-shoot ratio, photosynthesis efficiency, and nutritional quality of aeroponically grown butterhead lettuce. International Journal of Agricultural and Biological Engineering. https://www.ijabe.org/index.php/ijabe/article/view/6725

Aeroponics - enhanced yields - agrowtronics - iiot for growing. AGrowTronics. (2021, May 18). https://www.agrowtronics.com/aeroponics-enhanced-yields/#:~:text=The%20cycles%20are%20frequent%2C%20so,plants%20to%20grow%20to%20harvest

IEEE Xplore. (n.d.-a). https://ieeexplore.ieee.org/

Li, Q., Li, X., Tang, B., & Gu, M. (2018, October 24). Growth responses and root characteristics of lettuce grown in aeroponics, hydroponics, and substrate culture. MDPI. https://www.mdpi.com/2311-7524/4/4/35

Page updated

Report abuse