To survive space, humans must fight their own biology

Space · Published 21 October 2026 Swipe more like this →

In short: The International Space Station orbits at 17,100 mph, causing the sun to rise and set 16 times every single day. Because human bodies aren't evolved for this constant cycle, astronauts rely on artificial structures to prevent a spiral of permanent, crippling jet lag.

Maintaining a sense of normalcy is a primary engineering and psychological challenge for long-duration spaceflight. Because the ISS travels so rapidly around Earth, standard notions of day and night are rendered obsolete. To counter this, a strict 24-hour Earth day is maintained on board. This artificial schedule is essential to mitigate the physiological stress that would otherwise occur from constant light exposure. This constant orbital motion means astronauts experience a new sunrise and sunset every 90 minutes. Without these interventions, the human body would struggle to regulate its internal clock.

Beyond timekeeping, life in microgravity requires specialized systems for every basic human necessity. NASA employs a multidisciplinary team of medical physicians, psychologists, nutritionists, and exercise scientists to manage risks associated with spaceflight. These specialists design solutions for everything from optimal nutrition and hygiene—such as washing hair or brushing teeth—to the logistics of drinking coffee and using the bathroom in weightlessness. Specific technologies allow for unique habits like sipping from specialized drink bags or space cups. These systems are vital for maintaining daily routines in an environment where liquids behave differently.

The environment is also designed to support social and personal well-being. Astronauts utilize specific areas like Temporary Sleep Spaces (TESS) equipped with sleeping bags. Furthermore, NASA conducts simulated missions, such as those in the Human Exploration Research Analog (HERA), to study how crews maintain privacy, build group dynamics, and cope with family separation during deep space journeys to Mars. Crew members also have the right to participate in democratic processes via absentee ballots. Researchers use these simulations to observe how people adapt to unexpected circumstances during long-term isolation.

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