ISS Life Support Relies on Advanced Food Preservation and Water Reclamation

Sustaining human life aboard the International Space Station (ISS) requires highly specialized provisions engineered for mass efficiency and stability in microgravity. The logistical foundation of this endeavor rests on advanced food preservation techniques, primarily freeze-drying, a method in use since the Gemini program began in 1965. This process involves cooking, rapid freezing, and then using a vacuum chamber for water removal via sublimation, which preserves nutrients and allows for the rehydration of meals like scrambled eggs and pasta using injected water.

Practical adaptations in food format are necessary to maintain operational integrity; for instance, tortillas are preferred over traditional bread because they do not produce crumbs, which pose a hazard to sensitive electronic equipment throughout the station. Nutritional science remains paramount to astronaut health, specifically to counteract physiological degradation from prolonged microgravity exposure, such as muscle atrophy and bone density loss. Dietary intake is rigorously managed, with recent menu considerations including the addition of calcium-rich amaranth protein to bolster skeletal health. General dietary guidelines, reviewed by the Surgeon General and the National Research Council, serve as a baseline, often modified based on in-flight data; sodium intake is reduced to mitigate bone loss, while Vitamin D intake is increased due to the lack of natural synthesis from sunlight exposure.

Complementing the food system is the sophisticated Environmental Control and Life Support System (ECLSS), which manages water resources with high efficiency. The Water Recovery System (WRS) is central to this closed-loop life support, designed to minimize the costly resupply of water from Earth, which previously accounted for nearly half the payload mass of shuttle missions. This technology recovers approximately 93% of all used water from sources including crew urine, sweat, and exhaled breath moisture. The WRS employs complex stages, such as the Urine Processor Assembly (UPA) utilizing vacuum distillation via a Rotating Drum, to separate water vapor from contaminants, ensuring a continuous supply of potable water.

Looking toward extended voyages beyond low Earth orbit, space agencies are developing technologies for greater self-sufficiency, including pioneering efforts in extraterrestrial agriculture. Research, such as that conducted by teams at the University of Florida, has demonstrated the feasibility of growing plants in simulated lunar regolith, noting that germination was successful despite some growth variations. Other international projects, like the Moon-Rice collaboration involving the Italian Space Agency, focus on developing super-dwarf, nutrient-dense crops, such as rice mutants growing only 10 centimeters high, to optimize yield in limited space. These bio-regenerative life-support systems, relying on automated monitoring and critical water recycling, are viewed as essential for the physical sustenance and psychological well-being of future lunar base inhabitants and Mars explorers.