Celebrating 25 Years of Humanity in Space
In 2025, NASA and its international partners 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 the Artemis missions to the Moon and future voyages to Mars.
Beyond its role as a scientific platform, the station has been a bridge connecting cultures, sparking creativity and inspiring generations. The memories of Johnson Space Center employees reflect how the orbiting laboratory is not only an engineering marvel but also a deeply human endeavor.
Christopher Brown – Advancing life support systems for future exploration
As the space station’s Environmental Control and Life Support System (ECLSS) integrator, Christopher Brown’s role was to ensure astronauts had clean air and water. ECLSS removes carbon dioxide from the air, provides oxygen for breathing and recycles wastewater, transforming yesterday’s coffee into tomorrow’s coffee. Today, these systems make it possible to recover nearly 98% of the water brought to the station.
His proudest memory was fielding regenerative life support systems and making a symbolic toast with the crew while on the console in mission control. He also helped activate the water storage system, saving the crew time and improving operations at the station. For Brown, these milestones were vital steps toward future long-duration missions beyond Earth.
Stephanie Sipila – The heart of microgravity research
Stephanie Sipila, now responsible for integrating NASA’s extravehicular activities and human surface mobility program, began her career as a mechanical and robotic systems instructor for the orbital outpost. His favorite experiment, Engineered Heart Tissues, studies the effect of microgravity on the human heart to help develop new treatments for cardiovascular disease. She remembers NASA astronaut Sunita Williams running the Boston Marathon on a treadmill aboard the station, becoming the first person to complete the race in space and showing how astronauts stay connected to Earth while living in orbit.
Sipila also highlights the Spacesuit Art Project, an initiative that transformed the artwork of children with cancer into spacesuits carried and worn aboard the orbital outpost during live downlinks, connecting science, art and hope – and raising awareness of the cancer research being conducted aboard the orbital outpost.
Liz Warren – Where exploration meets humanity
Liz Warren, the space station’s associate chief scientist, saw first-hand how the Spacesuit Art Project raised children on Earth. During Expedition 52, she saw astronaut Jack Fischer wearing a suit covered in artwork created by young cancer patients, including her own daughter, a survivor. “It was incredibly moving to witness the power of art and inspiration. Human spaceflight requires courage, resilience and teamwork, just like the fight against childhood cancer,” Warren said.
His memories also extend to his tenure as operations manager for NASA’s Human Research Program, which uses research to develop methods to protect the health and performance of astronauts in space to prepare for long-duration missions. While heading away for the weekend, Warren received a call from the Payload Operations and Integration Center in Huntsville, Alabama. An astronaut on station, following a diet prescribed for a research study, wanted to swap a food item. Warren coordinated with her support team and relayed the decision to orbit, while continuing her run. That moment, she recalls, highlighted the constant, real-time connection between astronauts in space and teams on the ground.
Adam Baker – Checkmate: cleaning up space debris
As an aerospace engineer, Adam Baker helped monitor spacecraft experiments and operations from mission control. Baker remembers the time Mission Control played a live chess match with astronaut Greg Chamitoff during Expedition 17, a moment that showed the unique way the station connects crews in orbit with people on Earth. His favorite technical project, however, was the small satellite RemoveDebris, deployed from the station in 2018 to test space junk cleanup technologies. “Knowing that these experiments could one day help ensure the security of the orbital environment made this even more meaningful,” he said.
Michael McFarlane – Training for Success
As head of the Simulation and Graphics Branch, Michael McFarlane prepared astronauts for space station assembly missions using high-fidelity simulators. “My greatest memory is watching the station grow as we successfully executed assembly missions that looked a lot like what we had analyzed and trained for in our ground simulations,” he said.
A legacy of ingenuity and community
In the Mission Assessment Room, engineers not only troubleshoot in real time, but also celebrate milestones with traditions like “MERloween,” where controllers dress in space-themed costumes to honor the year’s lessons learned.
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 seeing NASA’s SpaceX Crew-9 crash land in 2025, greeted by dolphins in the Gulf of America. “I love writing about the science aboard the station that benefits humans on Earth,” he said.
For 25 years, the International Space Station has shown what humanity can accomplish together. Lessons learned on board will guide Artemis missions to the Moon and future voyages to Mars, ensuring that the next 25 years will be built on innovation, resilience and the human spirit.
