On January 3, 2019, China’s Chang’e-4 lander touched down on the far side of the Moon and launched the Yutu rover. Among many instruments, the rover was also carrying an important scientific experiment known as the Biological Experiment Payload (BEP). Over the next eight days, this payload conducted a vital experiment in which it attempted to grow the first plants on the moon. The load contained cotton, potato, Arabidopsis, and canola seeds, as well as fly eggs, yeast, and 18 mL (0.6 fl oz) of water maintained at constant atmospheric pressure.

The results of this experiment will help inform future bioregenerative life support system (BLSS) that will prove vital for habitats and missions beyond low Earth orbit (LEO). A team of scientists from China recently published a study examining the experiment, its results, and potential implications for future missions to the Moon, Mars, and other deep space locations. As a result, the experiment showed that plants could grow on the moon despite intense radiation, low gravity and long periods of intense light.

The team consisted of researchers from the Aerospace Research Center, the College of Aerospace Engineering, and the Key Laboratory of Tuber and Root Biology and Genetic Breeding at Chongqing University, as well as the China University and Laboratory of Electronic Science and Technology. Space Biology of the Chinese Academy of Agricultural Sciences in Chengdu.

Growing plants in lunar, Mars and space environments is important for many reasons. In addition to providing a power source and reducing the need for resupply missions, it will remove carbon dioxide and provide fresh oxygen, help recycle waste and improve crew well-being. While traditional environmental control and life support systems (ECLSS) rely on mechanical components that fail over time and need to be replaced, a bioregenerative system can regenerate itself over time.

This makes BLSS technology ideal for deep space missions where resupply opportunities will be scarce. Over the years, astronauts have conducted plant and algae experiments on the International Space Station (ISS), such as the Vegetable Production System (Veggie), Passive Orbital Nutrient Delivery System (PONDS), Augmented Plant Habitat (APH), and the Space Station. Real-Time Facility Avionics Controller Habitat (PHARM). However, it is still unknown how the natural environment of extraterrestrial objects will affect the operation of BLSS.

Lead author Xie Genxin, a professor of environmental engineering at Chongqing University Space Research Center, is also the lead developer of BEP. As he explained to Universe Today via email, being able to grow plants in space is a necessary step towards establishing bases beyond Earth:

“While a survival base is being established on the Moon, Mars and other extraterrestrial planets, it is not possible to move more things from Earth. “The need to use on-site resources to produce oxygen and food is particularly important and is the first step in establishing a survival base, so planting experiments are very important.”

First biological experiment

The BEP payload developed at Chongqing University was the first biological experiment performed by humans on the far side of the Moon. The purpose of the experiment was to evaluate the impact of lunar surface conditions (low gravity, intense radiation, and intense light) on the growth and health of terrestrial organisms. The payload weighs 2,608 kg (5.75 lb) with a height of 198 mm and a diameter of 173 mm (7.75 x 6.8 in), providing a total volume of 0.82 liters and a bioactive area of ​​0.42 liters. Sunlight was passed through the guide tube, allowing the plants inside to photosynthesize.

These six components make up the producers, consumers, and decomposers that make up all the elements necessary for an ecosystem to function. Plants were supposed to produce oxygen and nutrients through photosynthesis and be supported by fruit flies. Meanwhile, the yeast will act as a decomposition agent, recycling waste from flies and dead plants to create additional nutrients for the ecosystem. The experiment was the first of its kind and aimed to address scientists’ concerns about the Moon’s environment, Xie said:

“Before our experiment, many scientists were concerned that plants would not be able to germinate under the intense light and intense radiation conditions of the Moon, so we deliberately used natural sunlight on the Moon instead of artificial light for photosynthesis. At the same time, our biochargers were not designed to protect against radiation, which “It proves that plants can still grow under intense radiation conditions on the Moon.”

A few hours after the lander reached the surface, the biosphere temperature was adjusted to 24°C (75.2°F) and the seeds were watered. On January 15, it was reported that cotton, canola and potato seeds had germinated and internal images of BEP were published.

“This cargo includes animals, plants and microorganisms that form a micro ecosystem in a closed environment,” Xie Hengxin said at the time. “We direct sunlight at the tin, which is much stronger than on Earth. We will study their photosynthesis under strong sunlight and compare this with an experiment on Earth.”

Results

The next day, a moonlit night, the experiment entered a new phase when the outside temperature dropped to -52°C (-62°F) and the experiment was unable to maintain a comfortable temperature. The experiment continued to test the durability of the BEP as the temperature continued to drop, eventually reaching -190°C (-310°F). It was later reported that the germinating plants died, the potatoes did not sprout, and the fruit flies did not hatch. The total duration of the experiment was nine days instead of the planned 100 days. However, as Xie noted, valuable information was obtained. Xi said:

“Although our plants can grow on the moon under natural sunlight and radiation conditions, the safety of these plants has not been evaluated. Whether they are healthy requires further research. Our experiments also show how difficult it is to survive on the moon and how to survive a moonlit night. The first human on the moon “Our biological experiments fully demonstrate that it is possible to build a regenerative ecosystem to create a human base on the Moon.”

Looking ahead, Xie and his colleagues plan to conduct further experiments with stable lava tubes, which China is also considering as a potential base. “For the first time, we have sent six species from Earth to the Moon for biological experiments, an important milestone in establishing a basis for human survival on the Moon,” he said. “Our team is currently investigating how to create human bases and space farm experiments using lunar lava tube caves.”

NASA plans to send astronauts to the moon for the first time since the Apollo era in less than two years. China hopes to follow suit by sending the first taikonauts to the moon’s south polar region by 2030. These and other organizations such as ESA, Roscosmos and the Indian Space Research Organization (ISRO) have no less long-term goals. Establishing a permanent human outpost on the Moon that will enable research, exploration, international cooperation and deep space missions. An important aspect of this will be the use of local resources to meet crew needs.

One of the best ways to ensure constant food, breathable air, and crew health (physical and mental) is to build living quarters that can accommodate greenhouses and plant experiments. In short, astronauts must bring with them elements of the Earth biosphere to live, work and thrive in an extraterrestrial environment. The lessons learned from this study will help pave the way for anyone considering leaving.