Overcoming the challenges of growing plants in space

A plan is now unfolding at NASA to grow plants in space, in fact on the moon, when it returns to the lunar surface in the Artemis program, possibly within two years.

An Australian team from the Centre of Excellence in Plants for Space (P4S) is helping NASA.

Known as Lunar Effects on Agricultural Flora (LEAF), the project will collect plant growth and development data that will help scientists understand the use of plants grown for both human nutrition and life support on the Moon and beyond.

At this stage planning is for a September 2026 launch, but it’s a complex mission.

The project is led by Space Lab Technologies and involves researchers from universities internationally. Among them are scientists from Australia’s University of Adelaide and La Trobe University in Victoria, with additional analysis to be conducted by the P4S node at the University of Western Australia.

Spacelab says: “By bringing seedling samples back to Earth, as part of Artemis III, the research team will apply advanced system biology tools to study physiological responses at a molecular level. Only one other payload has studied plants on the moon; the 2019 Chinese Chang’e 4 mission provided a picture of a 4-day old cotton sprout then suffered thermal control failure.”

“The challenges of growing plants in Space can vary,” says Jenny Mortimer, P4S Chief Investigator and an associate professor at the University of Adelaide.

“It depends on where you want to grow them – in low earth orbit (LEO); on a planetary surface, or in a transit vehicle. All of these have their own challenges, although there are also challenges that are common to all these situations.

Leaf payload concept spacelab
LEAF paymoad concept (Spacelab website)

“In this project, we are building on longstanding efforts to grow plants on the International Space Station (ISS), and we’ll be taking the next step to the Lunar surface.

“The main challenge is the harsh conditions which include vacuum, extreme hot or cold temperatures, and damaging radiation.

“This means that in addition to providing all the things a plant needs to grow (light, nutrition, water, carbon-dioxide), we also need to provide protection to shield them from the radiation and give them a sealed atmosphere with thermal insulation.

“In turn, we have to ensure that the chamber itself, including its electronics, can withstand those harsh conditions too! The design of the LEAF chamber aims to do all of that. Importantly, it will operate autonomously once deployed. Astronauts are busy people!”

Professor Mathew Lewsey from La Trobe University Plants in Space team is also involved in the project. Lewsey says the growth chamber will weigh about 40 kg, and be about 35 cubic centimetres in volume.

Plants on space57. Jpg 1
The La Trobe University team: Jiayue Wang, Sofya Gvaramiya,  Mathew Lewsey, Frazer Thorpe, and Onkar Nath.

“The astronauts will carry it from the lander to the surface of the moon, deploy two solar panels that provide power to the capsule, then use a plunger to release water into the hydroponics and initiate plant growth,” he says.

“The capsule will transmit data back to the lander essentially over Wi-Fi – images and measurements.  After 3 to 5 days, depending on the final mission parameters, the astronauts will remove some samples to bring back for detailed on Earth analyses. The main capsule will stay there on the moon.”

Read more: Cosmos Magazine feature on plants in space

Mortimer says another major challenge is getting water to plant roots in microgravity. The LEAF chamber has a design which allows its plant growth system to operate with or without gravity.

“Some plants are better suited to growth in a completely controlled growth environment, and we know this from closed environment agriculture such as vertical farming here on Earth.

“These features include being small, fast growing, and where you can use as much of the plant as possible (low waste).

“Also, when thinking about feeding astronauts we want “pick and eat” crops – plants that will not provide an astronaut’s full calorie requirement but provide freshness (which is often much missed in a diet of prepackaged foods) and vitamins (which are often the least shelf-stable components of the food).

“We are exploring this question a lot more, including the role of biotechnology in developing better crops for these environments.

The plan is to send 3 plant species: Arabidopsis, Wolffia (a duckweed), and a variety of Brassica rapa (related to bok choy).

Wolffia is completely edible,” says Mortimer, ”…highly nutritious and fast growing. It divides vegetatively every 1 to 2 days. This means that it will divide during the experiment!

“Brassica rapa is an excellent choice of pick and eat plant, and Arabidopsis is a great model plant – it’s like the fruit fly or mouse of the plant world. All 3 plants have previous flown to the ISS, so we have some information on how they respond to microgravity, which we can build on.”

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