India to study spirulina and algae growth in space for future astronaut diets

India will conduct its first food and nutrition experiments aboard the International Space Station (ISS) as part of the upcoming Axiom Mission 4 (Ax-4) to study sustainable human living in space.

Group captain Shubhanshu Shukla, an astronaut at the ISRO (Indian Space Research Organisation), will conduct experiments on self-sustaining life support systems for future long-term space travel using microalgae.

He will be joined by US commander Peggy Whitson, a former NASA (National Aeronautics and Space Administration) astronaut, and two mission specialists from the ESA (European Space Agency), Sławosz Uznański-Wiśniewski and Tibor Kapu.

Growing nutritious microalgae

The first ISS experiment will study the impact of microgravity and space radiation on edible microalgae. This is a high-potential, nutrient-rich food source, reveals Dr. Jitendra Singh, Union Minister of State for Science and Technology, Earth Sciences, Atomic Energy, Space, and Personnel, Public Grievances, and Pensions.

The study will examine growth factors across algal species in space compared to Earth conditions. Singh notes that some species have a short life cycle and grow within 26 hours. In photobioreactors, they produce more biomass per unit volume than traditional crops. This makes them attractive to space missions that face space and resource constraints.

Shubhanshu Shukla, astronaut at the ISRO (Image credit: Axiom Space).The astronauts will use indigenously developed biotechnology kits provided by the Department of Biotechnology, designed for microgravity conditions and validated by scientists.

“Microalgae grow rapidly, produce high-protein biomass, absorb carbon dioxide, and release oxygen — making them perfect candidates for sustainable space nutrition and closed-loop life support systems,” adds Singh.

Nitrogen and carbon recycling for superfoods

The second experiment will study the growth and cellular metabolism of cyanobacteria — Spirulina and Synechococcus — under microgravity due to their high protein and vitamin content. 

They will be grown in urea- and nitrate-based media to see if they can be a space superfood. Nitrogen can be sourced from human waste. “These organisms could be the key to carbon and nitrogen recycling in spacecraft and future space habitats,” Singh says.

He adds that the Ax-4 mission affirms India’s influence over the global space sector through its science, sustainability, and exploration capabilities. The government believes the Ax-4 mission will shape how humans live, eat, and survive in space. 

In related research news, two professors from the University of Arizona, US, have developed a cost-effective spirulina-based nutrition solution in bioreactors to combat malnutrition. They outline that spirulina requires minimal land and fresh water, consumes carbon dioxide, and releases oxygen. 

Other scientists confirmed that Carolina azolla, a fast-growing floating fern, is free of harmful cyanotoxins and also holds potential as a sustainable food source to tackle food insecurity.