In 2025, NASA and its international partners will celebrate 25 years of continuous human presence aboard the International Space Station. Since November 2, 2000, more than 290 people from 26 countries have lived and worked aboard the orbiting laboratory, conducting thousands of experiments that have advanced science and technology on Earth and paved the way for Artemis missions to the Moon and future journeys to Mars.
In addition to its role as a scientific platform, the station has become a bridge connecting cultures, stimulating creativity and inspiring generations. The memories of Johnson Space Center staff reflect that the orbiting laboratory is not only an engineering marvel, but also a deeply human enterprise.
Christopher Brown – Development of life support systems for future research
As an environmental control and life support system for the space station (ECLSS) integrator, Christopher Brown's role was to provide clean air and water to the astronauts. ECLSS removes carbon dioxide from the air, supplies oxygen for breathing and recycles wastewater, turning yesterday's coffee into tomorrow's coffee. Today these systems can recover almost 98% of the water delivered to the station.
His proudest memory was commissioning the regenerative life support systems and raising a symbolic toast to the team from the flight control console. He also helped activate the water storage system, saving crew time and improving station performance. For Brown, these milestones were vital steps toward future long-term missions beyond Earth.
Stephanie Sipila – The Heart of Microgravity Research
Stephanie Sipila, now program integration manager for NASA's Extravehicular Activities and Human Terrestrial Mobility program, began her career as a mechanical and robotic systems instructor at an orbiting outpost. Her favorite experiment Engineered heart tissueis studying the effects of microgravity on the human heart to help develop new treatments for cardiovascular disease. She remembers a NASA astronaut Sunita Williams run the Boston Marathon on a treadmill aboard the station, become the first person to complete the race in space, and show how astronauts stay connected to Earth while living in orbit.
Sipila also emphasizes Spacesuit art projectinitiative that turned artwork from children with cancer into space suits carried and worn aboard the space station during live communications, integrating science, art and hope – and raising awareness of cancer research conducted aboard the orbital outpost.
Liz Warren – Where Research Meets Humanity
Space Station Deputy Chief Scientist Liz Warren saw first-hand how a spacesuit art project lifted the spirits of children on Earth. During Expedition 52, she watched astronaut Jack Fisher wear a suit decorated with artwork created by young cancer patients, including his own daughter, a survivor. “It was incredibly moving to celebrate the power of art and inspiration. Human spaceflight requires fortitude, resilience and teamwork, just like fighting childhood cancer,” Warren said.
Her memories also extend to her time as head of operations at NASA Human Exploration Programwhich uses research to develop methods to protect the health and performance of astronauts in space in preparation for long-duration missions. While walking over the weekend, Warren received a call from the Payload Control and Integration Center in Huntsville, Alabama. An astronaut on the station, following a diet prescribed for scientific research, wanted to replace some food item. Warren coordinated with her support team and transmitted the solution back into orbit while continuing the flight. She recalls that the moment highlighted the constant, real-time communication between astronauts in space and teams on the ground.
Adam Baker – Checkmate: Space Debris Cleanup
As an aerospace engineer, Adam Baker helped monitor experiments and spacecraft operations from mission control. Baker recalls how, during Expedition 17, mission control played a live chess match with astronaut Greg Chamitoff, a moment that highlighted the unique ways the station connects crews in orbit with people on Earth. However, his favorite technical project was the small satellite RemoveDebris, launched from the station in 2018 to test technologies for cleaning up space debris. “Knowing that these experiments could one day help ensure the safety of the orbital environment made this even more meaningful,” he said.
Michael McFarlane – Training for Success
As Chief of Simulation and Graphics, Michael McFarlane prepared astronauts for space station assembly missions using high-fidelity simulators. “My greatest memory is the growth of the station as we successfully completed assembly missions that were very similar to what we analyzed and trained in our ground simulations,” he said.
A Legacy of Ingenuity and Community
In the Mission Evaluation Room, engineers not only troubleshoot problems in real time, but also mark milestones with traditions such as “MERloween,” where controllers dress in space-themed costumes to honor the lessons learned throughout the year.
For social media consultant Mark Garcia, sharing the station's story with the public has been the highlight of his career. His favorite moment was watching NASA's SpaceX Crew-9 splash down in 2025, greeted by dolphins in the Gulf of America. “I enjoy writing about the science on board the station that benefits people on Earth,” he said.
For 25 years, the International Space Station has shown what humanity can achieve together. Lessons learned on board will inform Artemis missions to the Moon and future journeys to Mars, ensuring the next 25 years are built on innovation, sustainability and the human spirit.
