• 2 months ago
Satellites are disposed of in various ways, depending on how far away they are from Earth. But satellites that get damaged can't be disposed of and end up as space junk - the European Space Agency is looking to change that with a disposal mission.
Transcript
00:00What happens to space satellites when they're decommissioned?
00:09Satellites need small amounts of fuel to align themselves
00:12and maintain their position.
00:14When that fuel runs low, satellites are decommissioned.
00:19How they're disposed of depends on their orbit.
00:23Satellites circle the Earth at various altitudes depending
00:27on what rule they're designed for.
00:30Environmental satellites, for example,
00:32orbit a few hundred kilometers above the ground
00:35in low Earth orbit.
00:37Navigation satellites are much further away.
00:40They're at an altitude of around 20 to 24,000 kilometers
00:45in medium Earth orbit.
00:48Satellites for telecommunications, broadcasting,
00:51and weather forecasting are furthest from the Earth
00:54in what's known as geostationary orbit.
00:59They're positioned above the equator
01:01and are always focused on just one part of the Earth.
01:05After their mission, these satellites
01:08are blasted into a graveyard orbit.
01:10It's located around 300 kilometers
01:13above the geostationary orbit.
01:16This area is now densely populated.
01:19Once a satellite has reached the graveyard orbit,
01:22the control center must empty its tanks
01:24and drain the batteries to prevent
01:27an uncontrolled explosion through the fuel igniting,
01:30for example.
01:32Satellites in low Earth orbit are brought down
01:34in a controlled way and disposed of in the Earth's atmosphere.
01:39The increasing frictional heat causes
01:40them to largely burn up, with the remaining debris
01:43falling into the sea.
01:48Satellites may also be damaged by meteorites or space junk
01:52and have their lifespan shortened.
01:54They can no longer be controlled.
01:56Researchers are now hoping to recover them
01:59using rescue satellites.
02:01They'll either grab hold of the defunct spacecraft
02:04or capture it with a net.
02:06The aim is to bring them down in a controlled manner.
02:13The European Space Agency, ESA, is now
02:16preparing for its first disposal mission,
02:19dubbed Clear Space 1.
02:22Transcribed by ESO. Translated by —

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