Space Farming: The Benefits of Growing Plants in Orbit

Growing plants is an act of love. To see them grow beautifully, it is necessary to take care of them  and pay attention to every moment of their growth. Plants love us as well because their benefits are vital for us, giving us oxygen, food and mental comfort. 

Having flowers and plants is a huge opportunity not only on Earth but also on the International Space Station (ISS). Plants and vegetables create a positive atmosphere among the astronauts by lighting up the room, stimulating the senses and producing a calming effect and improving their general wellbeing. 

In Andy Weir’s sci-fi novel The Martian (later turned into a 2015 film starring Matt Damon), an astronaut is stranded on Mars after a mission goes awry. Until his crew can rescue him, the key to his survival lies in space farming, and he is forced to rely on his knowledge of botany to grow potatoes in Mars’ harsh climate as his food supplies lessen. 

But that doesn’t mean astrobotany is fiction — you could say it’s the science of the future considering the possibility to cultivate on the soil of other planets, decreasing the demand on Earth to gain constant resources for humanity requests. 

The benefits don't stop here. Firstly, cultivation on orbit allows astronauts to maintain good physical health during long-term missions, offering them the opportunity to have fresh meals and not just freeze-dried ones. 

Therefore, plants on orbit limit the economic consumption due to the transport of raw materials, reducing the amount of supplies needed. 

Astrobotany is the discipline that studies plants’ behavior in extra-terrestrial environments, derived from botany and astrobiology. The term was coined and used for the first time in 1954 by the Russian astronomer Gavriil Adrianovich Tikhov, whose career was focused on finding the presence of life beyond extra-terrestrial planets. This field has been fundamental because it led to the possibility of growing plants in orbit.

Limits and Benefits of Space Farming

The cultivation of plants and vegetables in orbit is called space farming. Initially, it ended up being too harsh to apply to non-Earth environments, but in past years, the ISS has welcomed a huge team of astronauts that have done experiments to explore and improved the general knowledge of cultivating green life in space.

Beginning with the obstacles, plants need gravity in order to grow their roots. In space, astronauts live in a microgravity condition, which means that there is less gravity. Scientists have been analyzing which plants can grow in this environment, opening the future possibilities to farm on the surface of Mars and the moon, known for having lower levels of gravity. Some vegetables include Arabidopsis (Thale cress), Bok choy (Chinese cabbage) and Tulips.

Secondly, when in orbit, there is no natural lighting and astronauts have to put plants in special growth chambers, which can welcome vegetation with artificial lighting. However astronauts must be really careful about the choice of lights in these chambers because the resources on orbit are limited. Energy cannot be wasted on light bulbs that don't maximize their output. Therefore, astronauts have to be really careful in choosing light bulbs that don’t create an exaggerated level of heat. In addition, they don’t have enough room to transport light bulbs through space, so they always need a source of light for a long period, such as LEDs.

In orbit, space is very limited as opposed to the massive farmlands on Earth. Researchers must develop an efficient system of machines that can contain the crops while they grow. The machines should be automatic and must be able to regulate watering, humidity, lighting, air circulation and nutrient delivery. Additionally, they should be able to exchange carbon dioxide and oxygen, in order to properly complete photosynthesis. 

In orbit, plants use the spacecraft's air, humidity and microgravity in order to grow. These conditions are different from those on Earth and researchers are studying whether any contaminants and dangerous organisms from space will affect space vegetation, making them inconsumable for humans. 

Even though astronauts have to face many challenges in space farming, beyond having or not the green thumb, cultivating vegetables on orbit has brought also many benefits. 

The main purpose of learning how to grow things at ISS is to allow long-term space exploration.

As a matter of fact, astronauts need regenerative food sources because they must eat fresh foods for their physical health. Bringing multivitamins  to Mars won’t be enough to keep physicians in a good shape of health! At ISS, astronauts receive regular doses of a wide variety of freeze-dried and prepackaged meals to cover their nutrition needs through the help of resupply missions - which help astronauts to receive fresh aliments stocked anytime they would need them. Plants can be used also to purify water and to recycle carbon dioxide into oxygen.

Therefore, improving this discipline could also expand human knowledge on agriculture because researchers hope to transfer their astro-botanical research in orbit to Earth, especially to challenge the future years of climate change and difficult environmental conditions. The goals in this field include higher quality crops, higher crop yields and better controlled agricultural systems and greenhouses. 

Space farming also brings to Earth some useful applications. For example, there is a special device called Bio-KES that converts ethylene into carbon dioxide and water using ultraviolet light. Ethylene causes plants to ripen and eventually spoil. If a device like Bio-KES would be used in food storage units, it could help increase the shelf life of plants, flowers and other perishable items. Ultraviolet light can also be used to kill pathogens like anthrax, help wounds heal faster and improve the effectiveness of some cancer treatments.

Space farming could bring positive consequences also in the study of plants’ cell walls. Scientists may discover how to regulate the sturdiness of plants, some of which could benefit and become stronger during dangerous weathers. In addition, trees with less-sturdy cell walls would grow faster and be easier and cheaper to process into paper. These genetically-modified trees could also slow down deforestation by becoming quick-growing resources for paper production.

VEGGIE

NASA is trying to find new ways to provide astronauts fresh and healthy vegetables and fruits for long term missions. The real challenge is the question of how to do that in a closed environment — without sunlight or Earth’s gravity.

 Aboard the ISS, the Vegetable Production System (also known as VEGGIE) has been developed, which is a living space garden created on the space station. Veggie’s purpose is to help NASA study plant growth in microgravity, while allowing astronauts to implement fresh food to their diet. 

Veggie typically holds six plants, each of which grows inside a container filled with a clay-based growth media and fertilizer. The containers are important to help distribute water, nutrients and air in a healthy balance around the roots. 

In the absence of gravity, plants use other environmental factors, such as light, to orient and guide growth. A series of light emitting diodes (LEDs) above the plants produces a spectrum of light used for suggesting the plants’ growth. The veggie chamber welcomes the astronauts with a particular magenta pink, due to the reflections by plants of green light and red and blue wavelengths.

Veggie has successfully grown a variety of plants, including three types of lettuce: Chinese cabbage, mizuna mustard, red Russian kale, and zinnia flowers. Some of the plants have been eaten by astronauts, and for now no harmful microbes attacked their system, allowing our scientists to enjoy safe and healthy food. 

From now on the field of space farming will embrace a new path of innovation and there are many projects that will take part in this journey.  

For example another chamber used for plant research is called the Advanced Plant Habitat (APH). 

APH is more enclosed and automated than Veggie, built with over 180 sensors that are in constant interactive contact with a team of researchers, so  it doesn’t need daily attention. Dr. Norman Lewis will be the first investigator using APH and he is particularly interested in the relationship between microgravity and plant lignin content. Lignins give structure and rigidity to plants in order to counteract gravity, like bones in humans. His research has the goal to find out a possibility to grow genetically engineered plants with less lignin, because microgravity causes a loss of lignin. They   would bring benefits for  long term expeditions, giving  a better nutrient absorption for human meals. 

Yours truly,

Alice Coppini

Writer, Writers Team