A Quarter Century in Space: Unlocking Earth's Potential and Beyond
For over 25 years, the International Space Station has been a beacon of human ingenuity, serving as a continuous living and working environment for astronauts. This remarkable feat has not only pushed the boundaries of exploration but has also revolutionized our understanding of life beyond Earth. From cultivating food and deciphering DNA to studying diseases and simulating Mars missions, every experiment aboard the orbiting laboratory brings us closer to sustaining human life in space while advancing scientific knowledge and technology that benefit people worldwide.
The space station offers scientists a unique laboratory, free from Earth's gravity. In this microgravity environment, cells grow in three dimensions, proteins form high-quality crystals, and biological systems reveal intricate details hidden by gravity. These conditions open new avenues for studying diseases and developing treatments. For instance, researchers have observed cancer cell growth, tested drug delivery methods, and examined protein structures linked to diseases like Parkinson's and Alzheimer's.
One notable study is the Angiex Cancer Therapy, which tested a drug targeting blood vessels that feed tumors. In microgravity, endothelial cells survive longer and behave more like those in the human body, providing researchers with a clearer understanding of the therapy's effectiveness and safety before human trials.
Protein Crystal Growth (PCG) is another critical area of cancer research. The NanoRacks-PCG Therapeutic Discovery and On-Orbit Crystals investigations have significantly advanced research on leukemia, breast cancer, and skin cancers. Protein crystals grown in microgravity exhibit larger, better-organized structures, enabling scientists to determine fine structural details that guide the design of targeted treatments.
Studies in orbit have also shed light on cardiovascular health, bone disorders, and the immune system's changes in space. This knowledge informs medical practices on Earth and prepares astronauts for long missions in deep space.
Feeding astronauts on long-duration missions goes beyond packaged meals. It demands sustainable systems for growing fresh food in space. The Vegetable Production System, or Veggie, is a garden on the space station designed to test plant growth in microgravity while providing fresh produce for the crew's diet and improving well-being in orbit.
Veggie has successfully grown lettuce, Chinese cabbage, mizuna mustard, red Russian kale, and even zinnia flowers. Astronauts have enjoyed space-grown lettuce, mustard greens, radishes, and chili peppers using Veggie and the Advanced Plant Habitat, a larger growth chamber that allows for more detailed crop studies.
These plant experiments pave the way for future lunar and Martian greenhouses by demonstrating how microgravity affects plant development, water and nutrient delivery, and microbial interactions. They also offer immediate benefits for Earth, advancing controlled-environment agriculture and vertical farming techniques that enhance food production efficiency and resilience in challenging environments.
Understanding the human body's changes in space is crucial for planning long-duration missions. NASA's Twins Study offered a unique opportunity to investigate nature vs. nurture in orbit and on Earth. NASA astronaut Scott Kelly spent nearly a year aboard the space station, while his identical twin, retired astronaut Mark Kelly, remained on Earth.
By comparing the twins before, during, and after the mission, researchers examined changes at the genomic, physiological, and behavioral levels. The results showed that most changes in Scott's body returned to baseline after his return, but some persisted, such as shifts in gene expression, telomere length, and immune system responses.
The study provided the most comprehensive molecular view of how the human body adapts to spaceflight. Its findings will guide NASA's Human Research Program for years, informing countermeasures for radiation, microgravity, and isolation. The research may also have implications for health on Earth, from understanding aging and disease to exploring treatments for stress-related disorders and traumatic brain injury.
The Twins Study demonstrated the human body's resilience in space and continues to shape medical protocols for the Artemis campaign to the Moon and future Mars missions.
The space station, an analog for deep space, complements Earth-based analog research simulating the spaceflight environment. Space station observations and challenges inform research questions and countermeasures on Earth.
This is currently being achieved through CHAPEA (Crew Health and Performance Exploration Analog), where volunteers live and work in a 1,700-square-foot, 3D-printed Mars habitat for about a year. The first CHAPEA crew completed 378 days in isolation in 2024, testing strategies for maintaining health, growing food, and sustaining morale under delayed communication.
NASA recently launched CHAPEA 2, with a four-person crew who began their 378-day simulated Mars mission on October 19, 2025. Building on lessons from the first mission and decades of space station research, they will test new technologies and behavioral countermeasures to help future explorers thrive during long-duration missions, preparing Artemis astronauts for the journey to the Moon and laying the foundation for the first human expeditions to Mars.
Maintaining health is a top priority for NASA astronauts, especially while living and working aboard the orbiting laboratory. Long-duration missions, lasting about six months or more, bring about significant changes to the human body due to the absence of Earth's gravity.
Proper nutrition and exercise are essential ways to mitigate these effects. NASA has a dedicated team of medical professionals, including physicians, psychologists, nutritionists, exercise scientists, and specialized medical personnel, who collaborate to ensure astronauts' health and fitness on the station. Led by a NASA flight surgeon, they regularly monitor crew health and individualize diet and fitness routines to prioritize health and safety in space.
Crew members also actively participate in ongoing health and performance research to advance our understanding of long-term spaceflight's effects on the human body. This knowledge is applied to any crewed mission and will enable humanity to travel farther than ever before, including to the Moon and Mars.
In 2016, NASA astronaut Kate Rubins made history aboard the orbital outpost as the first person to sequence DNA in space. Using a handheld device called the MinION, she analyzed DNA samples in microgravity, proving that genetic sequencing could be performed in low Earth orbit for the first time.
Her work advanced in-flight molecular diagnostics, long-duration cell culture, and molecular biology techniques such as liquid handling in microgravity. The ability to sequence DNA aboard the orbiting laboratory allows astronauts and scientists to identify microbes in real-time, monitor crew health, and study how living organisms adapt to spaceflight.
This research continues through the Genes in Space program, where students design DNA experiments that fly aboard NASA missions. Each investigation builds upon Rubins' milestone, paving the way for future explorers to diagnose illnesses, monitor environmental health, and search for signs of life beyond Earth.
