Satellite Explorer

Why do we need satellites?

Did you ever get your location on your phone or set the navigation system in the car to guide you to a destination? Then you've definitely used satellites.

Localization via satellite navigation systems is widely used in almost all industries: transportation, emergency response, farming, banking, military, science. These satellites determine the location, velocity, and current time of small electronic devices (like the ones in our smart phones).

Communications satellites are used for television, radio, and internet broadcasting. This sector increased lately with more and more companies launching satellites to provide internet everywhere on the globe.

Earth Observation satellites provide information about earth resources, weather, climate, and environmental monitoring. Imaging satellites produce high-resolution data of almost the entire landmass on earth.

Space Observation also benefits from satellite data: satellite telescopes have been critical to understanding phenomena like pulsars and black holes as well as measuring the age of the universe.

Where are satellite orbits?

Although the space beyond Earth's atmosphere is vast, man-made satellites are typically located in one of the three popular orbital regimes: low earth orbit, medium earth orbit and geosynchronous orbit.

Who owns all the satellites?

There are thousands of active satellites out there and 75 different countries have at least one satellite orbiting Earth. United States, China, and United Kingdom top the list of countries with hundreds of operational satellites.

When looking at individual satellite operators we can see that private companies own most of the active satellites. SpaceX is the big winner, with 1,735 satellites as of January 2022.

What is space debris?

Space debris represents defunct artificial objects in space which no longer serve a useful function. The debris is composed of old satellites, abandoned launch vehicle stages, mission-related debris, and fragmentation debris.

How much space debris is out there?

It's not possible to track all the debris objects. According to{' '} a European Space Agency article {' '} there are around:

36,500 pieces of debris
larger than 10 cm/4 inches

1,000,000 pieces of debris
larger than 1 cm/0.4 inches

130 million pieces of debris
about 1 mm/0.04 inches and larger

These objects travel at speeds up to 28,160 kph/17,500 mph so even if they are very small they can damage a spacecraft when travelling at these speeds.

Collisions in space

Satellite operators frequently maneuver their satellites to avoid potential collisions with debris fragments. There have been several prominent space collisions, whose fragments are displayed on the map (their positions are predicted as of March 28th, 2022). The collision in 2009 was accidental and the others were triggered on purpose by{' '} anti-satellite weapons .

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Who cleans up outer space?

Space debris poses a real challenge in the future, especially with the rise of megaconstellations. Space organizations and companies compete for innovative solutions to clean up debris and make outer space safer. Below are some examples of projects in development that use various technologies to clean up space:

IzaƱa-1 laser ranging station

The European Space Agency is testing a new laser ranging station in Tenerife, Spain. Using powerful lasers they can rapidly determine the location, velocity and orbit of previously invisible defunct objects. They can also gently nudge debris objects into new orbit to avoid collision. Read more about this technology on the{' '} ESA website .

Mission ClearSpace-1

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The mission, planned for 2025, will use a four-armed robot to capture a Vega Secondary Payload Adapter, left behind by ESA's Vega launcher in 2013. This is a partnership between the{' '} European Space Agency {' '} and{' '} ClearSpace , a Swiss based start-up.

ELSA spacecraft retrieval service

The idea of the program is to launch two spacecrafts - a servicer satellite and a client satellite - to track down and dock dead satellites and remove them from the orbit. Astroscale, the Japanese-based company behind the mission successfully carried tests in 2021 where they did multiple dockings and releasing of satellite targets. In 2022 they experienced difficulties with the test program. Read more about{' '} the mission on their website .


E-Space {' '} is a startup that plans to launch a network of satellites that would capture pieces of debris while in orbit. Once they have captured a set amount of debris they are programmed to de-orbit and burn up in the atmosphere. The first three test satellites will be launched later in 2022.