How Nasa biologist Sharmila Bhattacharya is prepping humans for space

Mint

14-06-2025

Sharmila Bhattacharya, a scientist at the US space agency Nasa, has long focused on a singular goal: understanding how space conditions affect living organisms and using that knowledge to protect human health in space.
For more than 25 years, she has focused on how phenomena like gravity and radiation impact tiny organisms like fruit flies and yeast, which share cellular and genetic traits with humans. These insights help develop strategies to safeguard astronauts.
Now leading science and technology utilisation at Nasa's Ames Research Center, she also oversees initiatives that apply science and technology to advance space exploration. 'My role includes working closely with those in computing and aerospace engineering as we explore ways to foster meaningful collaborations—whether with private aerospace firms, government bodies or international partners," she told Lounge in an interview last week. Bhattacharya was in India to speak alongside European Space Agency (ESA) flight surgeon Brigitte Godard at the Lodha Genius Programme, a joint initiative by Ashoka University and the Lodha Foundation. In their talk, 'Biology: A Bridge Between Science, Medicine, and Space Exploration", they drew on their careers—from supporting astronauts to launching space experiments—to highlight how biology shapes human health in extreme environments like the International Space Station (ISS).
'Whether it's insulin for diabetes or vaccines during the covid-19 pandemic, it all begins with basic research. The process starts with understanding biology at its most fundamental level. It's no different in space science," explains Bhattacharya for whom joining Nasa was a stroke of serendipity.
Born in Nigeria and raised in India, Bhattacharya, now 61, traces her love for biology to a school in Kolkata where teacher Leela Choudhury sparked her interest in the subject. She studied human physiology at Presidency College and then biological chemistry at Wellesley College in 1987. After a Ph.D. in molecular biology from Princeton and postdoctoral research in neurobiology at Stanford in 1999, she spotted a Nasa job ad seeking scientists with her precise background. She applied, was selected, and began her career at Nasa's Ames Research Center that very year.
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'You can learn a lot about human responses from these tiny creatures," Bhattacharya says, referring to fruit flies. During her postdoctoral research, for instance, she showed that 'you could take genes critical for synaptic communication (how brain cells use chemical signals to share information) from a mammal and insert them into a fruit fly, and the neurons would still communicate". It's the first step, according to her. 'You start with flies, yeast or rodents—then build up to human tissue models and eventually astronauts."
In 2018, as part of the Multi-use Variable-gravity Platform (MVP) Fly 01, she and her team at Nasa performed experiments on genetically identical fruit flies under three conditions: microgravity (where people or objects appear to be weightless), artificial gravity (emulating normal gravity, or 1G, in space) via centrifuge, and on Earth. 'The flies exposed to microgravity showed the most changes in brain function," she recalls.
Those exposed to artificial gravity had changes that fell between those seen in microgravity and on Earth, implying that artificial gravity might be a viable countermeasure to protect astronaut health on long missions. Artificial gravity, for instance, is already being explored for future commercial space stations. 'If rotating platforms or centrifuges become viable, we'll be able to test these countermeasures more directly in human environments," Bhattacharya elaborates.
Gravity, however, isn't the only variable in space. Radiation is another big one. On Earth, we're shielded by the atmosphere and the magnetic field. But beyond the Van Allen belts (which prevent the fastest, most energetic electrons from reaching Earth)—toward the Moon or Mars—exposure increases. The ISS, for instance, protects scientists by shielding against micro-meteoroids, radiation exposure controls in a pressurised, climate-controlled environment.
Orbiting within Earth's magnetosphere (the protective bubble around Earth created by its magnetic field) offers added protection. Onboard protocols, exercise, nutrition and health monitoring help mitigate the effects of microgravity and ensure astronaut safety during extended missions. But galactic cosmic rays, which are high-energy particles from outside our solar system, are harder to block—they can penetrate spacecraft and pose health risks to astronauts by damaging human cells.
Hence, to understand radiation's biological effects, in November 2022, Bhattacharya's lab pioneered the BioSentinel mission—a yeast-based biosatellite launched on the uncrewed Artemis I mission that sent the Orion spacecraft to a lunar orbit, and returned it to Earth after a 25-day journey.
In her current role at Nasa, she is also collaborating with scientists from other countries and from fields like aerospace engineering, computation, and commercial aerospace. This explains why she's closely following the Axiom-4 mission—the first time that India, Poland and Hungary will execute a mission aboard the ISS. Axiom-4 is a partnership between Nasa, Indian Space Research Organisation (Isro), US-based private space infrastructure developer Axiom Space Inc., and ESA.
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The Axiom Mission 4 crew, initially set to launch on 9 June but delayed due to a technical issue, will lift off aboard a SpaceX Dragon spacecraft en route to the ISS. Once docked, the astronauts—including Isro's Shubhanshu Shukla as pilot—will spend up to 14 days conducting science, outreach, and commercial work aboard the orbiting lab.
A FASCINATION FOR THE STARS
Bhattacharya is confident that space biology—and space science more broadly—will continue to grow. The reasons are twofold: more countries are now reaching for space, and the private sector is getting increasingly involved. She cites examples of companies like Elon Musk-owned SpaceX, Blue Origin, founded by Jeff Bezos, and other US-based companies including Axiom, Varda Space, and Vast. 'This opens up many more opportunities for science," she points out. In the past, for instance, researchers might have had to wait a year between spaceflight experiments. 'Now, we could potentially send one every other month."
She also believes that artificial intelligence (AI) and machine learning will be indispensable to future space missions. 'Imagine AI tools that can autonomously analyse data, optimise experiments, and adapt in real time during long missions. That's the kind of support we'll need as we go farther. As a species, we're wired to be curious," she says. 'AI will continue to work hand in hand with the research we're doing, helping us move faster and smarter."
When asked if there could be life beyond Earth, she points out that current space missions are already searching for water, oxygen, and other Earth-like conditions. Bhattacharya urges a broader perspective: 'Maybe life out there doesn't need oxygen or even carbon. Maybe we've seen it and didn't recognise it." That's where advanced sensors and human intuition must work hand in hand.
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For her, the future lies in collaboration: humans and machines, biology and engineering, nations and disciplines. She's also proud of mentoring the next generation. A recent highlight: her former postdoctoral trainee Ravi Kumar Hosamani now leads the Sprouts experiment aboard Axiom-4, studying fenugreek and moong dal in space—crops that could feed astronauts and support their health. And what's her advice to students? 'Stay curious. Trust your instincts. And don't be too hard on yourself. You never know where the path might lead."
Bhattacharya describes space as an emergent frontier, even though humanity has ventured there for decades. 'What gets me up in the morning is the love of science and technology. It's not a job, it's not work—it's fun," she says. 'The more nations work together in space, the more we learn—about the cosmos, about biology, and about ourselves."