How to grow crops in space
Plants grown in space could feed astronauts, but might new strains contribute to ending a food crisis here on Earth, too?
The plan seems to have some backing in science. According to the International Atomic Energy Agency, breeders have been using extreme physical stressors such as ionising radiation to create new heritable mutations in the DNA of plants for more than 70 years. Gamma rays, X-rays, fast neutrons and UV light have all been successfully tested on seeds, seedlings or pollen to create more resilient crops resistant to pests and extreme weather and capable of producing higher yields.
Space mutagenesis, as an extreme form of such crop treatment, has been used in China in particular since 1987, according to the Chinese Academy of Sciences. The eastern superpower has sent seeds of various species up on recoverable satellites, high-altitude platforms and the Shenzou spacecraft. The researchers found that in the extreme environment of space, with its cosmic radiation, microgravity and weak magnetic field, mutations in the DNA of plants occur at an increased rate of 1 per cent. On Earth, in comparison, these mutations occur at a rate of one in 200,000, according to Guo Rui, director of the Shaanxi Province Engineering Research Centre for Plant Space Breeding, who was quoted by the South China Post in 2018.
Further experimentation with the space-mutated crops led to the creation of more than 200 new mutant variants of crops including rice, wheat, cotton, sesame, pepper, tomato and alfalfa that have been, according to China Daily, released to Chinese farmers.
“There have been many published papers over the years showing specific instances where in the harsh environment some interesting biomass products emerge that can do quite well even in desert conditions,” Jeffrey Manber, the CEO of Nanoracks, told E&T. “These plants evolve in space either through changes on the genetic level or through the effects of radiation, the absence of gravity, or a combination of all these factors.”
China Daily claims that since approving its first type of space rice in 2003 for human consumption, China’s high-yielding disease-resistant space crops have helped alleviate poverty in many arid regions including the Tibetan plateau.
Nanoracks now wants to emulate China’s success in cooperation with the United Arab Emirates (UAE), a parched Arabian country that imports about 90 per cent of the food it needs to feed its inhabitants.
The US space firm has partnered with the Abu Dhabi Investment Office (ADIO) and plans to set up the StarLab Space Farming Centre in the UAE, where teams of researchers would study and select promising types of bacteria, microbes, biofilms and plants that would subsequently be sent to space to undergo mutations.
“We hope that at the end of 2021, we will be able to send our first research from StarLab to the ISS,” says Manber. “We might set up a small greenhouse in our Bishop Airlock and use it as a test bed and then maybe go into a stand-alone orbiting autonomous platform greenhouse in the next five years.”
Nanoracks’ Bishop Airlock is the first commercially funded airlock to have been sent to the International Space Station, where it will host small research payloads. It was delivered to the orbital outpost by SpaceX on 6 December 2020 and attached to the Tranquility module two weeks later.
After the trip to space, the plants would be subjected to more research and experiments with the goal of improving their most promising characteristics even further.
The UAE, already struggling with low agricultural productivity, hopes that the new crop species that emerge from these space mutation experiments will make the country more self-reliant and help secure the population’s needs even as global warming progresses.
According to 2016 data from the Food and Agriculture Organization of the United Nations, the UAE, mostly covered with deserts and plagued by the lack of freshwater resources, currently cultivates only about 5 per cent of its land. ADIO hopes that the new space-bred varieties might be able to grow even in some of the more arid areas.
“Covid and the climate change really opened our eyes to the fragility of food security in both the developing and the developed world,” Manber says. “We believe that there is a research pathway, where space could be one of the contributing solutions to how to overcome climate change and the increasing hazards of the Earth climate.”
The Nanoracks endeavour, Manber explains, goes in the opposite direction to most of the current space agriculture research, which looks at ways to feed astronauts in space, on the Moon and on a journey to Mars.
On 30 November 2020, astronauts on the ISS harvested radishes grown in the Advanced Plant Habitat, one of the facilities used for plant research on the space station. The produce was sent back to Earth for analysis but the reason why space agencies are investing in space farming research is to ultimately provide fresh vegetables for astronauts.
Nasa says that on a long-duration journey, such as a journey to Mars, multivitamin tablets would not be enough to keep astronauts healthy. While the crews on ISS can rely on regular deliveries of freeze-dried fruit from Earth, venturers into deep space would have to be more self-reliant.
ISS crews can already spice up their diet occasionally with fresh lettuce grown in the VEGGIE laboratory, a miniature space garden the size of a piece of carry-on luggage.
