International Space Station Overview

The International Space Station (ISS) is the largest and most complex international scientific project in history. It draws upon the scientific and technological resources of 16 nations including Canada, Japan, Russia, 11 nations of the European Space Agency and Brazil. The ISS provides scientists and engineers with ongoing access to the unique microgravity (very low gravity) environment of space. As a permanent space laboratory, the ISS allows scientists and engineers to discover entirely new materials, crystals and processes. Research is conducted in a variety of fields such as life sciences, materials, Earth observation and astronomy. It establishes a permanent human presence in space and result in the acquisition of knowledge required to conduct human missions to Mars and beyond.

The International Space Station has a mass of over a million pounds (440 000 kg). It measures more than 108 metres (356 feet) across and almost the same distance in length (almost 90 metres or 290 feet) with a large area of solar panels to provide electrical power to the six laboratories on board.

There have been 135 launches to the space station since the launch of the first module, Zarya, at 1:40 a.m. EST on Nov. 20, 1998: 74 Russian vehicles, 37 space shuttles, two European and two Japanese vehicles. The final space shuttle mission July 8-21 by Atlantis delivered 4 1/2 tons of supplies. Since the conclusion of the shuttle program to the ISS, people and supplies have been taken to the ISS on board Soyuz vehicles and Progress vehicles from Russia, and, most recently, on the Space Dragon, a commercial vehicle which to this point in time has taken cargo, but not people.

More than 160 spacewalks have been conducted in support of space station assembly totaling more than 1,015 hours. One of these walks was completed by Colonel Chris Hadfield, CSA Astronaut.  Colonel Hadfield was on the ISS from November, 2012 until May 2013 and served as Commander during that time. 


International Space Station
Photos by: NASA

(There is an excellent introduction to the ISS on the Canadian Space Agency website - students can watch the ISS formed and then see parts of the ISS using the magnifier.  Also on the site is a video of the current view of the ISS. )

The station is in an orbit with an altitude of 250 statute miles (400 km), allowing the station to be reached by the launch vehicles of all the international partners to deliver crews and supplies. The orbit also provides excellent Earth observations with coverage of 85 percent of the globe and over flight of 95 percent of the population.

Teachers and students can track the International Space Station using the following web site:

Students will also find the tour of the ISS with US astronaut Sunita (Suni) Williams to be particularly interesting. The tour is approximately 25 minutes long and can be found at‎. Suni holds the record for a female in space, having spent 322 days outside of the Earth's atmosphere.

The United States has the responsibility for developing and ultimately operating many of the elements and systems aboard the station. These include three connecting modules, or nodes, a laboratory module, four solar arrays, a habitation module, an unpressurized logistics carrier and a centrifuge module. The systems being developed by the United States include thermal control; life support; guidance, navigation and control; data handling; power systems; communications and tracking; ground operations facilities and launch-site processing facilities.

The international partners, Canada, Japan, the European Space Agency, and Russia, contribute the following key elements to the International Space Station:

CANADA has provided a 16 metre (55 foot) long robotic arm to be used for assembly and maintenance tasks on the Space Station. This mobile servicing system (MSS) includes three elements: the robotic arm Canadarm2, the mobile base system and the special purpose dexterous manipulator Dextre. The cost of designing, developing and installing the Mobile Service System is about $1.4 billion over 20 years but the economic benefits are estimated at $6 billion with 70 000 person-years of employment. Additionally, $2.8 billion has been generated in benefits and employment in the Canadian aerospace industry to date.

Canada is also taking the lead in some of the experiments associated with living in space for extended periods of time; this was one of the areas of focus for CSA astronaut Bob Thirsk's long-term mission in 2009. For more information on Canada's contribution to the international space program, see the chart at the bottom of the article on Biological Life Support Systems.

International Space StationThe European Space Agency has built a pressurized laboratory and provides logistics transport vehicles using the Ariane 5 launch vehicle.

Japan has built a laboratory with an attached exposed exterior platform for experiments as well as logistics transport vehicles.

Russia is providing two research modules; living quarters called the Service Module with its own life support and habitation systems. Russia also has provided a science power platform of solar arrays that can supply about 20 kilowatts of electrical power, logistics transport vehicles, and Soyuz spacecraft for crew return and transfer.

In addition, Brazil and Italy are contributing some equipment to the station through agreements with the United States.

The first phase of the International Space Station, the Shuttle-Mir Program, began in 1995 and involved more than two years of continuous stays by astronauts aboard the Russian Mir Space Station and nine Shuttle-Mir docking missions. Knowledge was gained in technology, international space operations and scientific research.

Seven U.S. astronauts spent a total of 32 months aboard Mir with 28 months of continuous occupancy starting in March 1996. Many of the research programs planned for the International Space Station benefit from longer stay times in space. The U.S. science program aboard the Mir was a pathfinder for more ambitious experiments planned for the new station. Dealing with the real-time challenges experienced during Shuttle-Mir missions has resulted in an unprecedented cooperation and trust between the U.S. and Russian space programs, and that cooperation and trust has enhanced the development of the International Space Station.

Tomatosphere is supported by Let's Talk Science, the Canadian Space Agency, HeinzSeed, Stokes Seeds, the University of Guelph, and First the Seed Foundation.