What happens to the human body when gravity disappears? How do muscles, bones, the brain, and even the mind respond to the extreme environment of space — and are we medically ready for a three-year mission to Mars?In this episode of the Space Curious Podcast, we're joined by Jérémie Sergé, an aerospace physician, weightless flight surgeon, and zero-G instructor with over two decades of experience across aerospace medicine, human performance, emergency medicine, and astronautics. Jérémie is Chief Medical Officer at Titan Space Industries and Chief Astronaut Officer and Dean of Titan Space Academy, where he's helping prepare the next generation of commercial astronauts. He is also one of only seven weightless flight surgeons in the world.What We Discussed:🔹 Childhood Dreams to Space Medicine — How Jérémie never let go of the childhood dream of space, and the philosophy of holding onto both your inner child and your wiser self🔹 The Role of an Aerospace Physician — What the day-to-day looks like, from astronaut medical support to parabolic flight campaigns, and how space medicine is shifting from a medicine of selection to a medicine of inclusion🔹 Parabolic Flights & Career Philosophy — How life's unlikely turns led Jérémie to become one of seven weightless flight surgeons globally, and why rigid career plans don't work🔹 What Happens to the Body in Weightlessness — Muscle loss, bone density reduction (1%+ per month), cardiovascular changes, fluid shifts, and why the body's adaptation is not pathology — it's intelligence🔹 Simulating Space on Earth — Bed rest studies, dry immersion, and why the only true weightlessness exists in parabolic flights and the space station🔹 Medical Risks in Space — The "space exposome": radiation, isolation, confinement, disrupted circadian rhythms, dust, noise, and limited medical capability — all happening simultaneously, not one at a time🔹 Moon vs. Mars — Partial gravity, abrasive lunar dust, 3-day distance from Earth vs. 22-minute communication delays, 900+ day missions, and the impossibility of evacuation from Mars🔹 Are We Ready for Mars? — We know enough to contemplate it seriously, but not enough to call it routine. The biggest challenge isn't physical — it's psychological🔹 The Mind in Space — Sleep disruption, sensory deprivation, monotony, isolation, crew psychology, and why we're not looking for the best individuals — we're looking for the best crews🔹 Building Space Healthcare Systems — Distributed medical capability, AI-assisted autonomous medicine, the need for generalists, and why even an artist belongs on a deep-space crew🔹 Pathways into Aerospace Medicine — Become a good doctor first, stay curious, remain transdisciplinary, and don't design a career just to collect space-related titles🔹 Commercial Astronauts & the Future — How space access is opening to a diverse range of participants, why disability can become ability in space, and the overview effect🔹 Myth-Busting — Weightlessness is not the absence of gravity (the ISS still experiences 90% of Earth's gravity), and astronauts are not super-athletes — they're the worst case of sedentarity🔹 A Child Born on Mars — The profound ethical question: at what point does adapting humanity to another world begin creating another humanity?🔹 Quick-Fire Round — Moon or Mars? Artificial gravity or biological adaptation? The most underrated threat in space? One item every Mars crew must carry? (Spoiler: curiosity)🔗 Connect with Jérémie Sergé on LinkedIn - https://www.linkedin.com/in/astrosapiens/🔔 Subscribe for more episodes exploring the mysteries of space, the human body, and the future of humanity beyond Earth!Are you hiring click here - https://danielernest.com/de-orbit #SpaceCurious #SpaceMedicine #AerospaceMedicine #HumanSpaceflight #ZeroG #Weightlessness #MarsMission #MoonToMars #SpaceHealth #AstronautTraining #SpaceCuriousPodcast