You have probably used space technology several times today without noticing. The weather forecast on your phone uses satellite images. The map app that found the bus stop used signals from GPS satellites about 20 000 km up. Live sports broadcasts, bank machines and the clocks that keep the power grid in step all depend on satellites. Space exploration is not only about astronauts and distant planets: much of it is about looking back at Earth. It also raises real questions about cost, pollution and junk left in orbit. In this lesson you will see how space technology works for people on Earth, what Canada has contributed, and how to weigh the benefits against the costs.
Satellites and orbits
A satellite is any object that orbits a larger body. The Moon is a natural satellite; the thousands of machines launched by people are artificial satellites. A satellite stays up because it is moving sideways very fast: it is constantly falling toward Earth, but it moves forward so quickly that Earth's curved surface keeps falling away beneath it. The higher the orbit, the longer one trip around takes. Astronauts on the International Space Station (ISS) float because they and the station are falling together (free fall), not because there is no gravity: at about 400 km up, gravity is still about 90% as strong as on the ground.
| Orbit | Height above Earth | Time for one orbit | Used for |
|---|---|---|---|
| Low Earth orbit (LEO) | about 160 to 2000 km (the ISS is at about 400 km) | about 90 minutes to 2 hours | Earth observation (like RADARSAT), the ISS, many internet satellites |
| Medium Earth orbit | about 20 000 km (GPS) | about 12 hours | Navigation: GPS and similar systems |
| Geostationary orbit (GEO) | 35 786 km above the equator | 24 hours, matching Earth's spin | Weather satellites watching a whole continent, TV and communications; the satellite stays over the same spot |
Watching Earth: climate change and natural disasters
Canada is huge, with long coastlines, Arctic sea ice and vast forests, so it relies heavily on satellites. The RADARSAT Constellation Mission (RCM) is a set of three Canadian satellites launched on June 12, 2019, about 600 km up. They carry synthetic aperture radar: instead of taking pictures with sunlight, they send out microwave pulses and record the echoes. Radar sees through clouds, smoke and darkness, which matters in a Canadian winter or during a storm. RCM can image most of Canada every day. Its images are used to map floods as they happen, track sea ice for ships in the Arctic, spot oil spills and ships, and monitor crops, forests and wetlands. It continues the work of RADARSAT-1 (1995) and RADARSAT-2 (2007), so scientists have decades of images to compare, which helps reveal long-term change.
- Weather satellites track hurricanes, storms and wildfire smoke, giving people time to prepare and evacuate.
- Climate monitoring: satellites measure sea-level rise, shrinking glaciers and ice sheets, ocean temperature and greenhouse gases. Canada's SCISAT satellite (launched 2003) studies the chemistry of the ozone layer.
- Wildfires: satellites detect hot spots and map burned areas. Canada is planning a dedicated wildfire-monitoring mission, WildFireSat, with a target of launching by 2029.
- Disaster response: through the International Charter "Space and Major Disasters," Canada and other space agencies share satellite images free of charge with countries hit by floods, earthquakes and other disasters.
Canada in space
| Contribution | What it does or did |
|---|---|
| Alouette 1 (1962) | Canada's first satellite; it made Canada the third country, after the Soviet Union and the United States, to design and build its own satellite. It studied the upper atmosphere. |
| Canadarm (1981 to 2011) | A 15 m robotic arm on NASA's space shuttles; it released and caught satellites and helped repair the Hubble Space Telescope. |
| Canadarm2 (2001 to today) | A 17.6 m robotic arm on the ISS that helped build the station, catches visiting cargo spacecraft and can move end over end to new spots. |
| Dextre (2008 to today) | A two-armed robot "handyman" on the ISS that does repair jobs, reducing the need for risky spacewalks. |
| RADARSAT satellites (1995, 2007, 2019) | Radar satellites that watch Canada's land, ice and oceans in any weather, day or night. |
| James Webb Space Telescope (2021) | Canada built the Fine Guidance Sensor and the NIRISS instrument. |
| Canadarm3 | A smart robotic arm first designed for NASA's planned Lunar Gateway station. In March 2026 NASA moved its plans away from the Gateway toward a base on the Moon's surface, and in August 2026 Canada announced it intends to repurpose its Canadarm3 work to support activities on the lunar surface. These plans may keep changing. |
- Marc Garneau: the first Canadian in space (1984).
- Roberta Bondar: the first Canadian woman in space (1992); a neurologist who studied how the body and nervous system respond to weightlessness.
- Chris Hadfield: the first Canadian to walk in space (2001, while helping install Canadarm2) and the first Canadian commander of the ISS (2013).
- Julie Payette: the first Canadian to board the ISS (1999); she operated the Canadarm and flew again in 2009.
- David Saint-Jacques: spent 204 days on the ISS (2018 to 2019), still the longest spaceflight by a Canadian as of 2026; he is a medical doctor, engineer and astrophysicist.
- Jeremy Hansen: flew on Artemis II in April 2026, becoming the first Canadian, and the first person who is not American, to travel around the Moon.
Spinoffs, costs and sustainability
- A spinoff is a technology developed for space that finds other uses on Earth.
- neuroArm: a robot for brain surgery developed at the University of Calgary with MDA, the Canadian space-robotics company behind Canadarm2 and Dextre, using space-robotics know-how. It was first used on a patient in 2008.
- Phone camera sensors: the small, low-power image sensors in most phone cameras grew out of research at NASA's Jet Propulsion Laboratory.
- Memory foam, first developed for NASA aircraft seats, and infrared ear thermometers, which use technology for measuring infrared radiation from stars and planets.
- Water purification systems built to recycle water on the ISS have been adapted to provide clean water in disaster zones and remote communities.
- Monitoring of climate, weather, floods, fires and ice that saves lives and property
- Communications, GPS navigation and accurate timing for everyday life
- New scientific knowledge about Earth, the solar system and the universe
- Spinoff technologies and skilled jobs in science, engineering and the trades
- International cooperation and inspiration for young people
- Missions cost billions of dollars that could be spent on other needs
- Rocket launches release soot and other pollutants high in the atmosphere
- Space debris threatens working satellites and astronauts
- Thousands of bright satellites interfere with telescopes and with everyone's view of the night sky, including Indigenous sky traditions
- Danger to astronauts, and unresolved questions about who may use resources on the Moon and beyond