Astronaut Shubhanshu Shukla On Space, ISS, Zero Gravity & Human Body | FO536 Raj Shamani
Executive Summary
Orbit, Shukla explains, is not escaping gravity but outrunning it: throw a ball hard enough and its fall keeps matching the curve of the Earth - so a rocket's real job is horizontal speed, 0 to 28,500 km/h in eight and a half minutes, pulling 4-5G on your chest (abort scenarios hit 18G, 'like an elephant sitting on you'). Up there the body rewrites itself: blood leaves the legs, the face swells, the heart shrinks, you grow taller and your back pays for it, your inner ear and eyes argue until space sickness passes, and 98% of all water - sweat and tears included - comes back to your cup. The emotional peak was flying over India at night: Bangalore, Hyderabad, Pune, Delhi, Lucknow, Kanpur in under a minute, and tears that simply accumulate in your eyes because tears do not fall in space. His path was never a straight ambition: a friend's leftover 20-rupee NDA form filled without telling his parents, an academy that broke him before it built him, fighter cockpits, a test-pilot course taken out of restlessness at 30, and a 2019 Gaganyaan call he applied to at his wife's insistence - followed by months of biomarker tests, physicals and a week of isolation with no sense of time. His message to every 12-year-old in India: things have a way of working out - keep the belief and keep working towards it.
Key Takeaways
Orbit is a controlled fall
Gravity is still up there - astronauts float because the spacecraft falls forward as fast as the Earth curves away. Newton's ball: thrown harder and harder, it eventually never lands. That is why a rocket's real cargo is speed, and why the closer you orbit, the faster you must go.
What launch does to a body
Zero to 28,500 km/h in eight and a half minutes - 4 to 5G sustained, eyes feeling pushed inward, chest compressed, arms suddenly untrainably heavy; crews learn to breathe through the stomach. An abort can mean 18G: 'like an elephant sitting on your chest.'
Space remakes the body
Blood migrates upward - the face swells, the heart no longer fights gravity and shrinks. You grow taller as the spine decompresses, and your back hurts for it. The vestibular system and the eyes disagree, so everyone gets space sickness - and for him it struck suddenly, not gradually. Radiation exposure caps how long missions can last; most changes reverse back on Earth.
Life inside the station
98% of the water is recycled - 'sweat and tears find their way back to your cup.' You sleep floating, strapped in a bag, in any orientation. Smell and taste dull as fluids shift, so spicy and salty food wins; his DFRL khichdi and pulao were shared with crewmates from Poland, Hungary and Japan, and he smuggled a request for dry kachori to the flight surgeon.
India from 400 km
On his third or fourth day he watched a night pass: the Indian Ocean, a purple flash of lightning in clouds, then Bangalore, Hyderabad, Pune, Delhi, Lucknow, Kanpur - the whole country in under a minute. 'Extremely emotional' - and the tears just pooled in his eyes, because tears do not fall in space.
The road to the cockpit
A Lucknow air show at ten (you see the jet before you hear it), a friend's leftover 20-rupee NDA form filled in secret, parents informed by the result in Employment News, an SSB in Dehradun his father permitted but did not fund, and an academy whose breaking period left his own mother unable to recognize him - before commissioning as a fighter pilot and falling for the MiG-21.
Selection is a psychology exam
After the PM's 2018 Gaganyaan announcement and the 2019 call, months of testing: blood markers in triplicate labs (about 40 vials a session), dental and muscle-tissue tolerance, 5 km runs, push-ups, sprints, broad jumps, swimming - and a 7-day isolation with no clock, food on demand and deliberately mundane team tasks. The rationale: they are selecting for how you cope, not just how you perform.
The Conversation Breakdown
Rocket science, explained to a kid
⏱ Untimed topicWhy you need a rocket at all, Newton's thrown ball, and the counterintuitive rules of orbital driving - closer means faster, farther means slower. How a capsule catches the ISS: staged burns from a 200 km injection, approach steps shrinking to centimeters per second, a probe engaging for soft dock, then motors pulling both craft into a hard mate - automatic throughout, with crew takeover possible at every single step.
Eight and a half minutes to orbit
⏱ Untimed topicThe launch from inside the seat: the slow-looking rocket that is anything but, 4-5G of sustained force, training for stomach breathing, and the abort scenarios that expose crews to 18G. Why stage cutoffs briefly return you to less than 1G and make the fluid in your inner ear slosh - the moment he felt he was tumbling while strapped in.
The human body in microgravity
⏱ Untimed topicFluid shift and its cascade - puffy face, thinner legs, a shrinking heart, dulled smell and taste, stretched spine and back pain, and the orientation conflict between eyes and inner ear that produces space sickness in everyone. Radiation as the real mission-length limiter, and the reassurance that most changes are reversible once home.
Living up there
⏱ Untimed topicThe recycling loop that returns sweat and tears to your cup; sleeping floating in a strapped bag with no mattress and no wall; crewmates sleeping upside down. Food diplomacy: DFRL-developed Indian dishes qualified for flight - khichdi, pulao, vegetables - shared around with the Polish, Hungarian and Japanese crewmates, plus Sunita Williams' warning that everyone can smell Indian food on station.
The night pass over India
⏱ Untimed topicHead down over the Indian Ocean, lightning flashing purple inside clouds, then the lit coastline and city after city he could name - the entire country crossed in under a minute, days into the mission, at the end of the busiest week of his life. Why crying in space means water gathering in your eyes, never falling.
NDA, fighters and the test-pilot itch
⏱ Untimed topicThe 20-rupee form, the Dehradun SSB, the letter to his future self written in school, and the academy that 'breaks you well' - followed by the Super Dimona first solo, valley flying, the honesty code of accident reporting ('there is no intent to cause damage'), flying the MiG-21 with love, evaluating the Rafale and F-16, and at 30, qualified and restless, choosing the test-pilot course at ASTE because he wanted to do more.
Gaganyaan: selection, isolation, belief
⏱ Untimed topicThe 2018 announcement, the 2019 call, his wife's push ('Rakesh Sharma went in 1984 - you should try'), his commanding officer laughing that he had applied too. Then the process: triplicate bloodwork, tissue tolerances, physical batteries, a 7-day isolation with no time cues, and Soyuz training in Russia. His closing message, framed as a letter to his 14-year-old self and every 12-year-old in India: things have a way of working out - have faith and keep working.
Core Frameworks & Ideas
Free fall is the destination
Orbit is falling toward the Earth and missing - continuously. The goal is not altitude but forward speed matched to the curve. In any system, stability can come from managed motion, not from standing still.
Backup at every step
Docking is automatic, but every stage has a manual takeover; training assumes automation fails. Reliability comes from rehearsed human override layered over automation, not from trusting either one alone.
Select for coping, not performance
The Gaganyaan process scored biomarkers and sprints, but its hardest instruments measured isolation tolerance, teamwork on boring tasks and composure without time cues. High-stakes environments should test how people degrade, not just how they shine.
Actionable Next Steps
- ✓Write a dated letter to your future self about what you hope becomes true - Shukla wrote his in school and reads it as the seed of everything after.
- ✓If you feel plateaued in a role you have mastered, treat the restlessness as a prompt to add a hard qualification, the way he chose test-pilot school at 30.
- ✓Preparing for a high-stakes selection? Train your isolation and boredom tolerance, not just the headline skills - that is what assessors actually watch.
- ✓Take a child (or yourself) to see the real thing live - an air show, a launch viewing, a factory floor. He saw the jet before he heard it, and it set the direction of his life.
Notable Quotes
“It is moving forward at great speed. It is falling. But the fall matches the curvature of the Earth, so it keeps going around. (translated from Hindi)”
“Can a child from a small village in India's Northeast become an astronaut? (translated from Hindi)”
“The most dangerous advice in the world is 'be practical' - only a person suffocated by an unlived dream ends up saying that. (translated from Hindi)”
The One Thing to Remember
The most dangerous advice in the world is 'be practical' - only a person suffocated by an unlived dream ends up saying that.