Space agencies like NASA, the European Space Agency (ESA), the China National Space Agency (CNSA), and others are working to return astronauts to the Moon for the first time since the Apollo Era. Mounting missions beyond Low Earth Orbit (LEO), something that has not happened in over 50 years, presents several major challenges. One of the biggest is that resupply missions take much longer to send to the Moon and require heavier launch vehicles. Whereas the International Space Station can be resupplied in a matter of hours by a Falcon 9, missions bound for the Moon take about three days and require a Space Launch System (SLS) or the Starship.
Hence why NASA and other space agencies are developing technologies that will allow missions to harvest local resources for building materials, water, propellant, and food – a process known as In-Situ Resource Utilization (ISRU). Whereas water ice (plentiful in the craters around the Moon’s southern polar region) can meet the demands for water and propellant, lunar regolith can be used to fashion building materials. Research has also shown that plants can be grown in lunar soil. According to a recent study by researchers from the University of Kent, this includes tea leaves.
The research was conducted by Professor Nigel Mason and Dr Sara Lopez-Gomollon, a Professor of Molecular Physics and a Lecturer in Plant RNA Biology (respectively). The research was a public/private collaboration between Kent and UK tea plantation, Dartmoor Estate Tea, Lightcurve Films, and Europlanet. It began after Maarten Roos-Serote attended the European Planetary Science Congress. As a freelance planetary scientist, Maarten attended a presentation on the space-agriculture activities at Kent’s School of Natural Sciences.
Dr Sara Lopez-Gomollon flanked by project students Anna-Maria Wirth and Florence Grant. Credit: Chris Wenham
Maarten then enlisted the help of Jo Harper, the co-founder of Dartmoor Estate Tea, the UK-based tea company, who provided the plants used in the experiment. Prof. Mason and Dr. Lopez-Gomollon planted saplings into lunar and Martian soil simulant and monitored how the plants developed over the course of several weeks. They compared their results with a control sample planted in Devonian soil, named for the Devonian period (ca. 419.2 to 358.9 million years ago). They also controlled the temperature, humidity, and lighting to mimic the conditions of a space habitat. Said Jo Harper:
The team at Dartmoor Estate Tea have been delighted to be involved in this study. We hope that our experience of establishing the cultivation of tea in an unconventional setting has assisted this project. Outcomes from the implementation of the trial phase have already led to direct improvements in the way we grow and nurture our plants here in Devon, with the potential for these to have applications benefiting the wider tea industry.
Project students Anna-Maria Wirth and Florence Grant monitored both groups’ soil moisture, nutrient content, pH, root length, and leaf health. The tea plants in the lunar soil simulant took root and grew as well as those in the control group, while plants in simulated Martian soil failed to grow. This is certainly good news for astronauts who are headed to the Moon in the coming years through the Artemis Program and other plans for lunar exploration. On the other hand, those bound for the Red Planet might have to wait a few years, which is good considering that crewed missions to Mars are still decades away. As Prof. Mason said:
We’re moving into a new age of space, where we think about settling in space and building bases on the Moon or Mars. One of the first things you want to know is, “What will people eat?” These experiments reveal that terrestrial plants such as tea may be cultivated in lunar soils within lunar greenhouses, allowing inhabitants of such bases some degree of autonomy and access to fresh food. We are at the very earliest stages of research into space agriculture, but it is reassuring that we may be able to provide access to the great British tradition of a tea break.
Physicist Florence Grant carefully assesses how the tea crops fared in the two types of soil, both mars and lunar, in this experiment. Credit: Chris Wenham
The experiment also has implications for life here on Earth. In assessing how plants can grow in extraterrestrial soil, the research team is also learning how crops and plants can survive in harsh environments with poor soil. This international problem continues to grow due to a combination of Climate Change and overfarming. This research could assist scientists working to restore formerly arable lands and turn sterile lands into viable plant-growing soils. The next step, according to Dr. Lopez-Gomollon, is to examine the physiology of the plants grown in lunar soil simulant more closely so they can conduct similar experiments with other crops:
This is particularly exciting as we move beyond simply sending astronauts to the Moon and begin to think seriously about making it habitable, paving the way for long-duration space missions. Additionally, just as our experience with how plants cope with stress on Earth informs our work in space agriculture, we hope that the knowledge gained from studying plant survival in extreme extra-terrestrial environments will also be applied to improving crop resilience here on Earth.
The project team reported their findings earlier this week at Europe’s first space agriculture workshop in Bratislava, Slovakia.
Further Reading: University of Kent