Can a tomato germinate on lunar soil? And if it is born and grows, what will be the conditions of the harvest? Will it be faster? Would it provide humans with the necessary nutrients? There is still no empirical answer to these questions. The only seeds grown on the Moon were cotton – they were planted by the Chinese in 2018, germinated and frozen within hours. A Spanish project, which emerged in Malaga, seeks to replicate the experiment by correcting the errors. Green Moon Project is close to planting a lunar garden. If all goes well, in four years they could send a capsule with carrot, tomato and lettuce seeds to the Moon. They have an agreement with the Chinese Space Agency for the future Chang’e 7 mission.
Tony Gannon, Vice President of Space Florida: “Space exploration already depends on private companies”
The project has an Andalusian flavor: it was born five years ago in two universities in Malaga and Cádiz. Gonzalo Moncada, biologist and Julián Serrano, energy engineer, both from UMA, together with Jose Maria Ortega, from Malaga and at that time a student of Aerospace engineering degree at the UCA, aspired to understand how a plant grows under the effects of lunar gravity. “Sending things into space costs a lot of money, so we wanted to reduce the sending of resources by cultivating there,” explains Ortega at the Les Roches Marbella hotel business school, where this week it was held. SUTUS 2021, the second international meeting of underwater and space tourism.
Sending permanent missions to the Moon or other celestial bodies and lunar tourism no longer belongs to the field of science fiction, and the dilemma of what to eat in a (less and less) hypothetical extraterrestrial station is not new. It is, in fact, the main plot axis of The martian, the novel by Andy Weir (2011), later adapted for film by Ridley Scott (Mars, 2015).
A job of almost a decade
Bernard Foing, an astrophysicist at the European Space Agency (ESA), believes that lunar travel is likely to be a reality in 20 to 40 years. Foing has been working for decades in Moon village, the Agency’s project to establish a lunar base. As explained in SUTUS, the goal is that by 2030 it has an infrastructure so that astronauts can stay for months.
If humans live on the Moon, they will need to feed. And then, a garden will not hurt. “We work with a deadline four years, but you have to be careful with the times in space, because many things are delayed, ”says Ortega.
If they succeed, it will have taken almost a decade since they presented it, in 2016, to Lab2Moon, within the ‘Google Lunar X Prize’ competition. Although it was not selected, the idea was a finalist among more than 3,400 projects. The following years matured the idea and incorporated some partners: the Astrobiology Center (made up of the CSIC and the Aerospace Technical Engineering Institute), the Geosciences Institute and the Granada-based company Innoplant are today part of Green Moon Project.
Andalusian tomatoes on Canarian soil
The project is supported on three terrestrial legs and a lunar one. The vegetable leg leads it Innoplant, a spinoff from the University of Granada specialized in agricultural technology and research. In their laboratories they work with the seeds of lettuce, tomato, radish and carrot, candidates for traveling to the Moon. “In the selection we have taken into account the vitamins and nutrients, but also the cycles and cultivation times,” explains Ortega.
The objective is to check what happens in the complete growth cycle: observe how the stem grows and the leaf develops, monitor its oxygen and carbon dioxide levels, and take images to observe the transport of nutrients from the root to the leaves. All of this must happen in two weeks of lunar experimentation.
La pata geológica, led by Jesús Martínez Frías, doctor in planetary geology and astrobiology from the Institute of Geosciences, studies the interaction of plants with the basaltic soil of Lanzarote. The Timanfaya National Park has yielded volcanic soil for experimental plantations. It is the most similar terrestrial soil to the lunar regolith.
Ortega and Jorge Pla, from Astrobiology Center, lead the technological part. “Our goal is to define the parameters that the capsule must have,” says Ortega. In other words: avoid that, as happened to the Chinese, plants freeze or burn with extreme temperatures (from 100 to -140 degrees Celsius on the Moon). For that you must have a “heat shield”, but not only that. The capsule is a totally closed, self-sufficient system, which should be able to reproduce on the Moon the constant conditions that facilitate plant life on Earth. That is, pressure, constant temperature around 20 degrees and luminosity with eight-hour cycles simulating blue, red and far red, which are the colors that favor photosynthesis.
Ortega says that it is still early to imagine lunar agriculture, but this project proposes a small-scale greenhouse, no bigger than a school desk, which also has to filter cosmic radiation. The energy will be obtained from solar radiation, from condensers and through the umbilical cord that connects it with the lander. The technology could also be used for delivery to other celestial bodies.
Finally, there is the most unstable leg, the X of the equation: what effect will lunar gravity – one sixth of Earth’s gravity – have on plant development? The hypothesis is that, the less effect of gravity, the growth will be faster. “It is something impossible to verify on Earth,” says Ortega. There are clinostats, small ramps that simulate inclinations to make the plant believe that there is another gravity, “but we always have a gravity vector looking towards the center of the earth.” Neither the microgravity generated in the parabolic flights works, because it is not constant. Even the International Space Station is affected by Earth’s gravity. It will do so in the conditions of temperature and radiation as similar to Earth as possible, on the regolith of Lanzarote, but under lunar gravity.
Therefore, only when the tomato reaches the Moon will we know how it grows. There will be many eyes on how the Andalusian-flavored garden flourishes. “Future crews have to be fed. The growth is being exponential, and we are going to have a lot of people up there ”, concludes Ortega.