The largest science laboratory built in space is orbiting the globe right now. The International Space Station, or ISS, flies at an average altitude of 400 kilometers (248 miles) above Earth. Every 90 minutes, this orbiting laboratory circles the globe at a speed of about 28,000 kilometers per hour (17,500 mph). In one day, the station travels about the distance it would take to go from Earth to the moon and back.
Why Build a Science Lab in Space? There are science laboratories on Earth. Why build a laboratory in space? One word: microgravity. In space, microgravity rules. On Earth, the force of gravity that we feel is called one gravity or 1 g. On the International Space Station, the crew members feel microgravity or µg, which is much less than 1 g. The "micro" in microgravity means "very small." As the space station orbits, it is in a state of free fall, meaning only gravity is pulling on it. If the station is falling around Earth, then so is everything inside the station. The free falling is what produces microgravity and causes objects to float.
When Earth's gravity is not a variable in an experiment, the experiment can have different results. In microgravity:
Flames burn differently.
Fluids do not flow the way they do on Earth.
Chemicals combine differently.
Crystals grow larger and better.
The human body changes and works differently.
Scientists and researchers around the world are learning new ways of doing science because of the work on the space station.
International Effort Imagine putting together a jigsaw puzzle. The puzzle has several pieces, and the pieces are made in different countries during different years. Now, put that puzzle together in space. In the simplest terms, that's what building the International Space Station was like.
The station is made of parts that were built in different countries. These countries put the "international" in the International Space Station. On Jan. 29, 1998, government officials from 15 countries met in Washington, D.C. There they signed agreements to cooperate to design, develop, operate and use a space station. Five space agencies work together on the International Space Station. NASA is the space agency of the United States. Russia, Canada and Japan along with 11 of the European Space Agency's nations partnered with the U.S. to build and operate the space station. Although they have not sent astronauts there, 44 other countries have used the space station for research.
Many Parts In 1998, the first station part, Zarya (ZAR-ee-uh), launched to space on a Russian Proton rocket. Zarya means "sunrise" in Russian. Its technical name is the Functional Cargo Block, or FGB (a Russian acronym). The Zarya module kept the station at the right altitude. Zarya was the station's communications center and power provider. The space shuttle delivered the first U.S.-built module, the Unity Node. The next piece was the Russian Zvezda (ZVEZ-dah) Service Module, which is where the crew would live while building the station. The truss was added as an attachment point for other parts. Gyroscopes and antennae were added. Finally, the space station was ready for the first crew.
The Crew A space station crew is called an expedition. The first crew, Expedition One, launched to the station aboard a Russian Soyuz rocket. Soyuz launches from the Baikonur Cosmodrome in Kazakhstan, a country bordering Russia. NASA astronaut Bill Shepherd was the commander of Expedition One. He and Russian cosmonauts Sergei Krikalev and Yuri Gidzenko launched on Oct. 31, 2000, and arrived at the station on Nov. 2, 2000.
Since then, the International Space Station has always had a crew living on board. A crew lives and works on the station from three to six months at a time. During the first years of the station, a crew of three performed experiments and assembled the station. At times, the space shuttle would ferry crew members up and back home. The shuttle also brought the large components to the station. Shuttle astronauts also helped build the station. As they worked, the station grew.
On May 29, 2009, the space station became the home of the first six-person crew with Expedition 20. The inside of the station is about the size of a five-bedroom house. The space station is the length and width of an American football field including the end zones. The station is solar-powered. Solar arrays gather sunlight and energize the station’s batteries.
After 36 shuttle missions, 161 spacewalks and more than 1,000 hours of spacewalking time, the crew completed the station in 2011. The space shuttle is retired now, but the Soyuz still transports the station crew to and from the station. A Soyuz capsule stays docked at the station in case the crew needs to make an emergency getaway.
The Russian Progress spacecraft, the European Automated Transfer Vehicle and the Japanese H-II Transfer Vehicle bring supplies to the station. The United States will send supplies to the station by a new spacecraft called SpaceX Dragon. These supply ships fly without a crew.
A Great Space for Science Experiments on the station are not like experiments on Earth. A different gravity environment means different results.
The space station partners use the orbiting laboratory for these main areas:
Biology and Biotechnology -- life science.
Physical Sciences -- chemicals, forces, motion.
Technology Development and Demonstration.
Earth and Space Science.
Exposed experiments are done outside the station. Small samples of materials are placed outside the station and exposed to space to see if they change. The crew performs other experiments inside. The space station has three main laboratories on the U.S. segment: the U.S. Destiny lab, the European Columbus lab and the Japanese Kibo (kee-bo) lab. These labs have racks that are the size of large refrigerators. The racks hold the experiments.
NASA and its partners have performed more than 1,100 scientific investigations on board. More than 1,600 scientists have been involved in space station experiments.
The station also plays a role in education. All of the partner agencies use the station to educate their students back on Earth. Contests and other opportunities allow students to send experiments to the space station. Astronauts and cosmonauts demonstrate science concepts for students from the station. They also answer student questions during events called educational downlinks. During a downlink, large groups of students have a live video conference with astronauts. More than 30 million students around the world have participated in educational activities with the space station.
NASA and its partners plan to use the International Space Station until 2020.
In This Module
This module has video clips from:
A NASA International Space Station scientist.
An astronaut who has spent more than a year, total time, on the space station.
A tour of the space station by an astronaut.
Plus, the module has links to many more videos and pictures to build a great podcast episode.
Preview video clips, audio clips and images under Space Station Resources on your right. Download the ones you want to include in your podcast.
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Record your narration.
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More About the Space Station
We have created a Web page with additional International Space Station information that can be used to help build your podcast.