ISRO aiming for a rich harvest in space

GROUP Captain Shubhanshu Shukla is poised to become the second Indian astronaut to travel to space, four decades after Rakesh Sharma’s spaceflight onboard Russia’s Soyuz spacecraft in 1984. The historic Axiom Space Mission-4 (AX-4) is set to be launched from NASA’s Kennedy Space Centre on June 10 atop SpaceX’s Falcon 9 rocket.

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Shukla is scheduled to conduct food and nutrition-related experiments under a collaboration between the Indian Space Research Organisation (ISRO) and India’s Department of Biotechnology, with support from NASA. It will be a watershed moment for ISRO’s space biology and space agriculture experimentation. Shukla will also take part in five joint studies planned by NASA for its human research programme.

Around 8,000 years ago, along the fertile banks of the Indus river and other river valley civilisations, early farmers began experimenting with growing plants for food. This marked the beginning of one of humanity’s greatest revolutions, the first Agricultural Revolution. Instead of depending just on hunting and gathering, these ancient people started cultivating crops, leading to settled communities, surplus food and the rise of civilisations.

Fast-forward to today, and we stand on the brink of another ground-breaking feat in the emerging field of space

agriculture. Just as our ancestors explored how to grow food on Earth, scientists are now figuring out how to farm in space. Shukla and other crew members of AX-4 will be conducting experiments on seed germination and plant physiology in microgravity, the near-weightless environment of space, to understand how plants grow beyond Earth.

As humans venture into deep space, whether to the Moon, Mars or beyond, we will need fresh food. Astronauts on the International Space Station (ISS) already have small gardens, not just for nutrition but also for mental wellbeing. Imagine being hundreds of kilometres from Earth; a simple green plant can be a comforting reminder of home.

But space farming is not just about comfort; it is about survival. On long missions, astronauts cannot rely solely on packaged meals. Vitamins in pre-packaged food degrade over time, leading to potential health issues. History shows us what happens when humans lack fresh food. Sailors once suffered from scurvy due to vitamin C deficiency. To avoid similar problems in space, scientists are working on ways to grow fresh, nutrient-rich produce in spacecraft.

Some plants could even become space pharmacies. Researchers have already grown lettuce, which produces protein to help prevent bone loss, a significant issue for astronauts living in low gravity. Instead of carrying all their medicine, future space travellers might grow their own medicinal plants.

For thousands of years, farmers have worked with a simple rule: roots grow down, shoots grow up. But why? How does a plant ‘know’ which way is up?

In 1880, Charles Darwin noticed something strange — when plants grow on a slope, their roots do not just go straight down; they curve slightly. He thought gravity and surface contact caused this bending, which is called ‘root skewing’. For over a century, scientists agreed, until an experiment on the ISS in 2010 changed everything.

In space, where gravity’s pull is almost absent, roots still grew in that curved pattern. This means gravity is not the only force guiding plant growth. So, what is?

Life on Earth evolved under gravity’s constant pull. Roots grew downward to find water and nutrients, while shoots reached upward for sunlight. But in space, without gravity, plants behave differently.

Scientists have discovered that plants adapt to microgravity by changing their gene expressions. For example, roots in space start behaving like leaves, activating light-sensing genes that generally have no function underground. Meanwhile, leaves produce more insect-defence chemicals despite no bugs in space. These changes suggest that space-grown plants might develop unique traits, some of which could make them hardier or more nutritious.

Two exciting Indian experiments, part of the AX-4 mission, are helping unlock these mysteries. The first, ‘Sprouting Salad Seeds in Space’, is led by the University of Agricultural Sciences, Dharwad, and IIT-Dharwad. This study compares methi and green gram sprouts grown in space with those grown on Earth, checking if space sprouts are safe to eat and free from toxins or harmful microbes.

The second experiment, ‘Impact of Microgravity on Food Crop Seeds’, is a collaboration between the Indian Institute of Space Science and Technology and Kerala Agricultural University. Seeds of six crops will be exposed to space conditions and brought back to Earth. Researchers will then track their growth over several generations to see if space-induced changes result in variations in yield or resilience.

When studying plants on Earth, we only see “what is” rather than “what could be” in their physiology. We uncover fundamental biological truths by comparing growth in microgravity (aboard spacecraft) with ground controls in normal gravity. These space experiments with plants, cells and microorganisms reveal hidden aspects of growth and development that gravity usually masks. Such research provides unprecedented insights into the deeper workings of plant biology that Earth-based studies alone cannot achieve.

Understanding how plants grow in space is crucial for future colonies on the Moon or Mars. If we can farm efficiently beyond Earth, astronauts will not need constant resupply missions; they will grow their own food.

Just as the Indus Valley farmers revolutionised agriculture millennia ago, today’s scientists are paving the way for the next great farming revolution — one that could sustain humanity among the stars. The story of agriculture is still being written, and the next chapter may unfold not just on Earth but across the cosmos.

TV Venkateswaran is Visiting Professor, IISER-Mohali.