International Space Station Quiz

The first module of the ISS was launched in 1998, 14 years after President Reagan’s 1984 State of the Union Address in which he directed NASA to build an international space station.

Initial construction was completed in 2011, but new modules and platforms, such as the Russian Nauka Multipurpose Laboratory Module and the Prichal Docking Module, continued to be added to the orbiting laboratory through November 2021.

It took 42 assembly flights to construct the ISS. The U.S. space shuttles Endeavor, Discovery, and Atlantis completed 37 assembly flights to deliver the large modules and other pieces of the ISS, and five additional construction missions used Russian Proton and Soyuz rockets.

More than 270 spacewalks have been conducted for the assembly, maintenance, and upgrade of the ISS since 1998.

According to NASA, it would weigh approximately 935,000 pounds, anywhere from 880,000 to 990,000 pounds depending on the precise mass at any given time. That is the equivalent of about 230 average-sized cars!

The ISS orbits Earth every 92 minutes (1 hour 32 minutes), which allows astronauts to see as many as 16 sunrises and sunsets a day.

The ISS orbits approximately 250 miles above the Earth, ranging from a minimum of 174 miles to a maximum of 285 miles. The ISS is in “low Earth orbit,” which means it travels relatively close to the Earth’s surface.

Humans have had a continual presence in space onboard the ISS since the year 2000.

Peggy Whitson has spent the most time onboard the ISS. By April 2025, she had spent a total of 675 days onboard the ISS across multiple missions.

The ISS is 356 feet long, which is the equivalent of a standard professional football fi

Five space agencies contributed to the construction of the ISS: NASA, Roscosmos (the Russian Space Agency), the European Space Agency, the Canadian Space Agency, and JAXA (Japanese Space Agency).

The Olympic Torch has been onboard the ISS one time — unlit, of course, for safety reasons. Two Russian cosmonauts took the Olympic Torch onboard the ISS in November 2013 during the lead up to the 2014 Sochi Winter Olympics.

Launched on November 20, 1998, Zarya, which means “sunrise” or “dawn” in Russian, was the first ISS module. It provided electrical power, storage, propulsion, and guidance to the ISS during the initial stage of assembly.

The ISS has eight main solar arrays, which generate between 75 to 90 kilowatts of power, enough to provide electricity to 40 homes. In 2021, six Roll-Out Solar Arrays were added to the existing solar panels to boost the power provided to the ISS. NASA plans to install the final two Roll-Out Solar Arrays in 2025.

There are 16 pressurized modules on the ISS: eight were provided by the U.S., six by Russia, one by Japan, and one by Europe.

The ISS travels at 17,500 miles per hour. In a 24-hour period, it travels the distance it would take to go to the Moon and back.

Astronauts onboard the ISS need to work out at least 2.5 hours per day. In the microgravity environment of space, they experience about 89% of the gravity we experience on Earth, and the weightlessness can lead to significant muscle and bone loss over time if precautions are not taken.

Eight spacecraft can be connected to the ISS at one time.

The 55-foot robotic arm on the ISS is called Canadarm2. It has seven different joints and two end-effectors, or hands, and is used to move entire modules, deploy science experiments, and even transport spacewalking astronauts.

The Water Recovery System (WRS) recovers sweat, liquid waste (urine), and excess water from the interior of the ISS and runs it through a purification process for reuse. This system reduces the need for water delivered by a cargo spacecraft by 65%.

A spacecraft can arrive at the ISS in as few as 4 hours, but the time for spacecraft to reach the ISS varies significantly depending on the type of spacecraft, the launch window, and the purpose of the mission.

The typical astronaut mission onboard the ISS is 6 months, and there are typically three to six crew members on the spacecraft at a time.

More than 3,000 experiments have been sent to the ISS. The majority have been related to biology and biotechnology, while others have investigated the physical sciences, Earth and space science, and technology development.

Over 15 million lines of code are used both in space and on the ground to support the ISS. All of this code is essential for the complex operations, life support systems, scientific experiments, and communication required to keep the ISS functioning safely and effectively.

In 2005, Congress designated the U.S. portion of the ISS as a National Laboratory for improving life on Earth, advancing STEM education, and fostering relationships among NASA, other federal agencies, and the private sector.

More than 200 research projects have been sent to the ISS since 2011. From improving quality of life for cancer patients to developing innovative treatments for osteoporosis, identifying potential solutions to address climate change, improving robotics systems, and even manufacturing artificial tissues in space, ISS National Lab research is helping to solve some of the world’s most pressing challenges.