The International Space Station Marks 25 Years of Continuous Human Presence 

On Nov. 2, 2025, NASA honored 25 years of continuous human presence aboard the International Space Station. What began as a fragile framework of modules has evolved into a springboard for international cooperation, advanced scientific research and technology demonstrations, the development of a low Earth orbit economy, and NASA’s next great leaps in exploration, including crewed missions to the Moon and Mars. 

The first expedition

This legacy of achievement in global human endeavors began with the first crew’s arrival to the space station on Nov. 2, 2000. Expedition 1 crew members NASA astronaut William M. Shepherd and Russian Aviation and Space Agency, now Roscosmos, cosmonauts Yuri P. Gidzenko and Sergei K. Krikalev launched from the Baikonur Cosmodrome in Kazakhstan two days prior. After a successful docking, the crew transferred aboard the station and began bringing it to life. Their primary tasks during their four-month mission included installing and activating the life support and communications systems and working with three visiting space shuttle crews to continue the station’s assembly. The trio returned to Earth in March 2001 aboard space shuttle Discovery, after having turned the station over to the Expedition 2 crew. 

(Space)walking into history 

Assembly and maintenance of the International Space Station would not be possible without the skilled work of crew members performing intricate tasks, in bulky spacesuits, in the harsh environment of space. In addition to station upkeep, spacewalks provide a platform for testing and improving spacesuits and tools – critical information for future exploration of the Moon and Mars. Other spacewalks have included operations for scientific research. In Jan. 2025, for example, crew members collected samples for an investigation examining whether microorganisms have exited through station vents and can survive in space, to better inform spacecraft design that helps prevent human contamination of Mars and other destinations. 

More than 270 spacewalks dedicated to the space station have been accomplished in the last quarter century. Several made station and human spaceflight history: 

• May 1999: NASA astronaut Tamara Jernigan became the first woman to complete a spacewalk at the space station, in support of its construction. 

• September 2000: Also during space station assembly, NASA astronaut Edward T. “Ed” Lu and Roscosmos cosmonaut Yuri I. Malenchenko conducted the first U.S.-Russian spacewalk. 

• March 10, 2001: NASA astronauts James Voss and Susan Helms set the record for longest spacewalk in U.S. history, at 8 hours and 56 minutes. 

• First spacewalks by international partners included: 

• April 2001 – Canadian Space Agency astronaut Chris Hadfield 

• July 2005 – Japan Aerospace Exploration Agency astronaut Soichi Noguchi 

• Aug. 2006 – European Space Agency astronaut Thomas Reiter 

• Feb. 26, 2004: NASA astronaut Mike Foale and Russian cosmonaut Aleksandr Y. Kaleri complete the first spacewalk with no one inside the station.  

• Oct. 18, 2019: The first all-female spacewalk in history, conducted by NASA astronauts Christina Koch and Jessica Meir. 

Orbiting laboratory welcomes first commercial crew 

The International Space Station welcomed its first commercial crew members on May 31, 2020, when former NASA astronauts Robert Behnken and Douglas Hurley joined Expedition 63 Commander and NASA astronaut Chris Cassidy and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner aboard the orbiting laboratory.  

Behnken and Hurley lifted off from Kennedy Space Center in Florida the day before on NASA’s SpaceX Demo-2 test flight – the first launch of American astronauts from U.S. soil since the space shuttle’s retirement in 2011.  

The duo quickly integrated with the rest of the crew and participated in a number of scientific experiments, spacewalks, and public engagement events during their 62 days aboard station. Overall, the pair spent 64 days in orbit, completed 1,024 orbits around Earth, and contributed more than 100 hours of time to supporting the orbiting laboratory’s investigations before splashing down on Aug. 2.  

Successful completion of the Demo-2 mission paved the way for regular SpaceX flights carrying astronauts to and from the space station. With another certified crew transportation system in place, the International Space Station Program added research time and increased the opportunity for discovery aboard humanity’s testbed for exploration, including preparations for human exploration of the Moon and Mars. 

Frank Rubio’s record-breaking year in space  

On Sept. 27, 2023, NASA astronaut Frank Rubio returned to Earth after spending 371 days aboard the International Space Station—the longest single spaceflight by a U.S. astronaut in history. His mission surpassed the previous record of 355 days, set by NASA astronaut Mark Vande Hei, and provided scientists with an unprecedented look at how the human body adapts to more than a year in microgravity. 

Rubio’s record-setting mission supported six human research studies, including investigations into diet, exercise, and overall physiology and psychology. He was the first astronaut to test whether limited workout equipment could still maintain health and fitness, an important consideration for future spacecraft with tighter living quarters. He also contributed biological samples, surveys, and tests for NASA’s Spaceflight Standard Measures, a study that collects health data from astronauts to better understand how the body adapts to space—knowledge that helps prepare crews for the Artemis campaign to the Moon and future trips to Mars. 

Alongside his fellow crew members, Rubio participated in dozens of investigations and technology demonstrations, from growing tomato plants with hydroponic and aeroponic techniques to materials science experiments that advance spacecraft design. 

Long-duration missions help inform future spaceflight and lay the groundwork for the next era of human exploration.  

A global foundation for growing a low Earth orbit economy 

The space station is one of the most ambitious international collaborations ever attempted. It brings together international flight crews, multiple launch vehicles, globally distributed launch and flight operations, training, engineering, and development facilities, communications networks, and the international scientific research community for the benefit of all humanity.  

An international partnership of space agencies operates the elements of the orbiting laboratory: NASA, Roscosmos, ESA (European Space Agency), JAXA (Japan Aerospace Exploration Agency), and CSA (Canadian Space Agency). Each partner takes primary responsibility for managing and running the station hardware it provides, as well as on-Earth construction, launch support, mission operations, communications, and research and technology facilities that support the station. 

At least 290 individuals representing 26 countries, and the five international partners have visited the orbiting laboratory during its 25 years of continuous human presence. Some of those visitors flew to the station on private astronaut missions. These missions contribute to scientific, outreach, and commercial activities. They also help demonstrate the demand for future commercial space stations and are an important component of NASA’s strategy for enabling a robust and competitive commercial economy in low Earth orbit. 

The results of the international partnership created through the space station and its accomplishments exemplifies how countries can work together to overcome complex challenges and achieve collaborative goals. 

Explore More

8 min read

Sugars, ‘Gum,’ Stardust Found in NASA’s Asteroid Bennu Samples

Article


3 hours ago

5 min read

Mark Elder: Building the Future of Spacewalking for Artemis and Beyond 

Article


1 day ago

3 min read

Rings of Rock in the Sahara 

In southeastern Libya, Jabal Arkanū’s concentric rock rings stand as relics of past geologic forces…

Article


4 days ago

Powered by WPeMatico

Get The Details…
Linda E. Grimm

What is AI? (Grades 5-8)

4 Min Read

What is AI? (Grades 5-8)

This article is for students grades 5-8.

What is AI?

Artificial intelligence, or AI, is a type of technology that helps machines and computers have “thinking” abilities similar to humans. Devices using AI can learn words and concepts, recognize objects, see patterns, or make predictions. They can also be taught how to work autonomously. AI is often used to help people understand and solve problems more quickly than they could on their own.

AI includes:

• Machine learning: This type of AI looks at large amounts of data and learns how to make fast and accurate predictions based on that data. 
• Deep learning: This type helps computers operate much like the human brain. It uses several layers of “thought” to recognize patterns and learn new information. Deep learning is a type of machine learning. 
• Generative AI: A human can use generative AI to create text, videos, images, and more. It is based on deep learning.

How is NASA using AI?

NASA has found uses for AI in many of its missions and programs.

For missions to the Moon, AI can use satellite imagery to create detailed 3D maps of dark craters. This data could help scientists plan missions, spot hazards, and even identify where future crews might find water ice. On Mars, the Perseverance rover uses AI to drive itself autonomously. It takes pictures of the ground, sees obstacles, and chooses the safest path.

AI also helps NASA search for planets outside our solar system. For example, AI has helped citizen scientists find over 10,000 pairs of binary stars. These pairs orbit each other and block each other’s light. This information could help scientists search for new planets and learn more about how stars form.

———————————————————————————————

Words to Know

Autonomous: acting or operating independently, without external control. An autonomous technology can perform duties without human intervention.

Citizen scientist: a member of the public, often a volunteer, who collects data that can be used by scientists. When members of the public participate in research in this way, it’s called citizen science.

———————————————————————————————

NASA also uses AI to support its work on Earth.  The agency uses AI to aid disaster relief efforts during and after natural disasters like hurricanes or wildfires. For example, AI can count tarps on roofs in satellite images to measure damage after a storm. NASA is also supporting flight controllers and pilots by using AI to plan better flight routes, making air travel safer and more efficient. 

AI is helping NASA explore space, protect people, and make amazing discoveries!

Advice From NASA AI Experts

“AI is a great field for people who like solving problems, building things, or asking questions about how the world works. People use AI to help doctors understand diseases, to teach robots how to explore space,  and to help communities prepare for things like floods or wildfires. If you like using technology to help people and discover new things, AI could be a great career for you!” – Krista Kinnard, NASA’s Deputy Chief AI Officer

Career Corner

NASA roles that may involve AI include:  
Astronauts: Astronauts on the International Space Station can use an AI “digital assistant” to get medical recommendations. This is helpful when communication with Earth is interrupted. It could also be useful on future missions to distant destinations like Mars.
Engineers: Engineers can use AI to help them generate designs for things like new spacecraft.
Astronomers: AI helps astronomers analyze satellite and deep space telescope data to find stars and exoplanets.
Meteorologists: Weather experts can use machine learning to make climate projections.
Programmers: Programmers can use AI to update code used in older missions, bringing it up to modern standards.
IT professionals: AI can enable IT experts to understand outages across NASA, allowing them to get programs back up and running faster.
Program managers: Program managers can use AI to plan and model NASA missions.

Explore More

Build Your Computer Science Skills With NASA
Gaining Traction on Mars Activity
NASA Space Detective: Can You Spot a Star or a Galaxy
Video: Hack Into Computer Science With NASA 
Artificial Intelligence at NASA

Powered by WPeMatico

Get The Details…
Sandra May

Sagittarius B2 Molecular Cloud

The Mid-Infrared Instrument (MIRI) on NASA’s James Webb Space Telescope captured glowing cosmic dust heated by very young massive stars in unprecedented detail in this image of the Sagittarius B2 (Sgr B2) molecular cloud released on Sept. 24, 2025.

Sgr B2 is the most massive, and active star-forming region in our galaxy, located only a few hundred light years from our central supermassive black hole. While Sgr B2 has only 10% of the galactic center’s gas, it produces 50% of its stars. Astronomers want to figure out why it is so much more active than the rest of the galactic center.

MIRI has both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum. MIRI’s view reveals colorful stars punctuated occasionally by bright clouds of gas and dust. Further research into these stars will reveal details of their masses and ages, which will help astronomers better understand the process of star formation in this dense, active galactic center region.

Image credit: Image: NASA, ESA, CSA, STScI, Adam Ginsburg (University of Florida), Nazar Budaiev (University of Florida), Taehwa Yoo (University of Florida); Image Processing: Alyssa Pagan (STScI)

Powered by WPeMatico

Get The Details…
Monika Luabeya

Mark Elder: Building the Future of Spacewalking for Artemis and Beyond 

For more than 25 years, Mark Elder has helped make human spaceflight safe and possible. As the International Space Station EVA hardware manager in the Extravehicular Activity (EVA) Office within the EVA and Human Surface Mobility Program, he leads the team responsible for the spacesuits, tools, and logistics that keep astronauts protected during spacewalks—and ensures NASA is ready for the next era of Artemis exploration. 

His team is programmatically responsible for the Extravehicular Mobility Unit, or EMU, spacesuit. That means every bolt, bearing, and battery astronauts rely on outside the International Space Station ultimately falls under their watch. He also oversees the EVA Space Operations Contract, which provides engineering and technical support to keep spacesuit systems flight ready. 

Elder’s work directly supports every EVA, or spacewalk, conducted at the station. His team coordinates with astronauts, engineers, and the Mission Control Center in Houston to make sure the suits and tools operate reliably in the most unforgiving environment imaginable. Their work helps ensure every EVA is conducted safely and successfully. 

Elder’s passion for NASA began at an early age. 

“When I was little, my parents gave me a book called ‘The Astronauts,’” he said. “It had drawings of a reusable spacecraft—the space shuttle—and I fell in love with it. From then on, I told everyone I was going to work at NASA.” 

That dream took off at age 16, when he attended Space Academy in Huntsville, Alabama. “That cemented my dream of someday working at NASA, and it taught me a little bit more about the different roles within the agency,” he said. 

While attending Case Western Reserve University as a mechanical engineering student, he learned about a new NASA program that allowed college students to design and build an experiment and then come to Johnson Space Center for a week to fly with their experiment on the Boeing KC-135 Stratotanker. “I jumped on the chance to be part of the team,” he said. “The experience further cemented my dream of working at NASA one day—Johnson in particular.” 

After graduation, Elder worked with Pratt & Whitney on jet engines. While the experience was invaluable, he knew his heart belonged in human spaceflight. “I learned that one of Pratt’s fellow companies under the United Technologies umbrella was Hamilton Sundstrand, which was the prime contractor for the spacesuit,” he said. “I jumped at the chance to transfer, and my career at NASA finally began.” 

Elder spent his first three years at Johnson performing tool-to-tool fit checks on spacewalking equipment, giving him hands-on experience with nearly every tool that he would eventually become responsible for as a hardware manager. 

His early years coincided with the shuttle return-to-flight era, when he worked on reinforced carbon-carbon panel repairs and thermal protection systems. Those experiences built his technical foundation and prepared him for the leadership roles to come. 

Over time, Elder took on increasingly complex assignments, eventually leading the team that developed the EVA Long Life Battery—the first human-rated lithium battery used in space. His team created a rigorous test plan to certify the battery for human spaceflight at a time when lithium batteries were under scrutiny for safety concerns. 

“Finally signing the certification paperwork was satisfying, but watching an EVA powered by the batteries provided a great sense of pride,” he said. 

This innovation set the stage for future generations of even safer, higher-capacity batteries that power today’s spacewalking operations and will eventually support lunar surface activities. 

Looking back, Elder said some of his greatest lessons came from learning how to lead with purpose. “The great thing about NASA is the highly motivated and dedicated workforce,” he said. “When I first became a team lead, I thought success meant making quick decisions and moving fast. I learned that leadership is really about listening. Strong teams are built on trust and open communication.” 

Another defining lesson, he said, has been learning to assume positive intent. “In a place like NASA, everyone is deeply passionate about what they do,” he said. “It’s easy to misinterpret a disagreement as opposition, but when you remember that everyone is working toward the same goal, the conversation changes. You focus on solving problems, not winning arguments.” 

That mindset has guided Elder through some of NASA’s most complex programs and helped him build lasting partnerships across the agency. 

Today, Elder’s work extends beyond the orbiting laboratory. As NASA prepares for Artemis missions to the Moon, his team’s experience maintaining and improving the EMU informs the design of next-generation exploration suits. 

“The foundation we’ve built on the space station is critical for the future,” he said. “Every tool we’ve refined, every system we’ve upgraded—it all feeds into how we’ll operate on the lunar surface and eventually on Mars.” 

Elder believes that the key to future success lies in perseverance. He advises the next generation to never stop dreaming. “My path wasn’t direct, and it would have been easy for me to give up,” he said. “But dreams have a way of guiding you if you don’t let go of them.” 

When he’s not supporting those missions, Elder’s creativity takes shape in his workshop. “In my spare time, I love woodworking,” he said. “Building something useful from a pile of rough-sawn boards helps calm me and gives me a great sense of accomplishment. I love being able to build furniture for my family,” he added, after recently finishing a desk for his youngest son. 

The same patience and precision he brings to woodworking defines his approach to exploration—steady progress, careful craftmanship, and attention to detail. “As NASA goes to the Moon and Mars, there will be challenges,” Elder said. “As long as we keep dreaming, we will see the next generation walking on the Moon and heading to Mars.” 

Explore More

5 min read

NASA’s 2025 Astronaut Candidates: Shaping Artemis Exploration 

Article


7 days ago

4 min read

The Overview Effect: Astronaut Perspectives from 25 Years in Low Earth Orbit

Article


1 week ago

5 min read

NASA Johnson Celebrates 25 Years of Humanity in Space 

Article


2 weeks ago

Powered by WPeMatico

Get The Details…
Sumer Loggins