Generally, we trust that what is going on above our heads in the cosmos is all A-OK, we trust that NASA, Roscosmos (the Russian version of NASA), CSA (Canada’s Space Association), or any other body for space exploration know what they’re doing, and can divert any potential disasters.
But in reality, things can sometimes be a little more haphazard than they would like you to believe.
Read on to find out whether satellites crash into each other, and read about a few historical instances where satellites have gone wrong.
- What Is A Satellite?
- Do Satellites Crash Into Each Other?
- How Do NASA (And Other Space Associations) Try To Prevent Satellite Collisions?
- Artificial Satellite Collisions
- Natural Satellite and Artificial Satellite Collisions
- Accounts Of Satellite Collision Avoidance
- Final Thoughts
What Is A Satellite?
First things first, we have to define what exactly we mean by the term satellite so that we know what we are going to be discussing in this article.
NASA defines a satellite as an object that orbits a planet or a star (so it can be a man-made machine, a moon, or even a whole planet). For example, the earth is a satellite, as it orbits the sun, and the moon is a satellite as it orbits the earth.
The moon and the earth are natural satellites, as they weren’t put there by man, but generally what we think of when we talk about satellites is a machine that has been launched into space, and moves around the earth (or another body in space).
These satellites are known as artificial and communicate back to stations on earth. Some record data that helps meteorologists on earth predict the weather by tracking storms and hurricanes.
Others take pictures of space, to help scientists, and will send back photos of other planets, the sun, black holes, dark matter, or even faraway galaxies. This aids humans’ understanding of our solar system, and the rest of the universe.
Artificial satellites are used for day-to-day communication as well, and it is certain that information you have consumed in the last day has been through a satellite. They beam TV signals and phone calls across the world.
A group of more than 20 satellites makes up the Global Positioning System (GPS), which figure out the exact location of GPS receivers across the world.
Do Satellites Crash Into Each Other?
The short answer to this question is yes, satellites sometimes do crash into each other, but it happens very infrequently.
This is because global space agencies are good at planning the orbit routes of their satellites so that they avoid one another, and are good at averting or redirecting satellites when it looks as though they may collide.
However, the occurrence of satellite collisions is likely to increase as the years go on, and there is more and more man-made space debris.
This debris is the result of decommissioned spacecraft, rocket bodies, space probes, satellites, or space stations.
As more things are launched into space (the vast majority of which never come back to earth), the more debris we have in earth’s orbit and the higher number of satellite collisions that we have.
How Do NASA (And Other Space Associations) Try To Prevent Satellite Collisions?
NASA and space associations across the world keep track of all of the satellites in space.
Collisions are so rare because when a satellite is launched, it is put into an orbit designed to avoid other satellites.
When collisions between satellites do happen, it is usually because orbits have gradually changed over time, and satellites have strayed into each other’s paths.
As more and more satellites are launched into space, the chance of a collision increases.
Natural Satellite Collisions
There have been no recorded cases of collisions between natural satellites that have been orbiting in any solar system, planet or moon. It is believed, however, that there have been collisions between natural satellites in the past.
Collision candidates for past events include:
- The impact craters can be seen on Jupiter and Saturn’s moons. These might have been caused by collisions with smaller moons, asteroids, or comets during the ‘Late Heavy Bombardment (which is a hypothesized cosmic event, which occurred around four billion years ago, where a disproportionately large amount of asteroids collided with terrestrial bodies).
- The far side of the moon may have been formed through the impact of a smaller moon (which was initially created alongside the moon, during the giant impact event).
- The objects that make the Rings of Saturn are believed to continually collide (and subsequently aggregate with one another), which has led to debris with limited size, which is constrained to a thin plane. Though this is believed to be a constantly ongoing cosmic process, this hasn’t been directly observed.
Artificial Satellite Collisions
Compared with natural satellites, there are far more recorded cases of artificial satellites crashing into one another, or other things, generally, astronomers classify artificial satellite collisions as one of three things. These are:
- Intentional collisions that are intended to destroy the satellite, either as a way to test anti-satellite weapons, or to destroy satellites that might pose a hazard if they were to reenter the earth’s atmosphere intact. For example, during the 70s and 80s, the Soviet Union had a program, known as Istrebitel Sputnikov, where IS-A satellites intercepted and destroyed target satellites that were specifically launched for the tests.
- Unintentional low-speed collisions, usually occur during failed rendezvous or docking space operations. In 1994, one of these collisions occurred between the crewed Soyus TM17 spacecraft and the Russian Mir space station. There was another example of one of these kinds of collisions in 2005, when the USA DART spacecraft and the MUBLCOM communications satellite, whilst they were performing orbital rendezvous maneuvers.
- An unintentional high-speed collision that happens between nay active satellites, and orbital debris that has found its way into their path. There was a collision in 2009, between the Russian Iridium 33 communication satellite, and the derelict Russian spacecraft, Kosmos 2251, which caused both satellites to be destroyed. In 1996, there was a collision between the French military’s reconnaissance satellite, Cerise, and debris from the European Ariane rocket. Most recently, in March 2021 there was a collision between Yunhai-1 02, and space debris from the Zenit-2 (which is the rocket body that launches the Tselina-2 rocket in 1996).
Natural Satellite and Artificial Satellite Collisions
There are also a few recorded occurrences of collisions between artificial satellites and natural satellites (such as the moon!). Here are some of these examples:
- The USSR Luna 2 spacecraft collided with the Earth’s Moon in the September of 1959.
- There have been no recorded collisions between artificial satellites and martian moons.
- There have been no recorded collisions between artificial satellites and Jovian moons, however it is worth noting that in order to avoid a collision with the Jovian moon Europa (which could contaminate the moon with microbes from earth), NASA’s Gallileo space probe was intentionally de orbited, by plunging it into Jupiter’s atmosphere in September 2003.
- There have been no recorded collision between artificial satellites and Saturnian moons, however, the European Space Agency’s Huygens probe, did make a controlled landing on Saturn’s Titan moon on January 14th, 2005.
Accounts Of Satellite Collision Avoidance
Satellite operators at space agencies across the globe frequently maneuver their satellites around, to avoid any potential collisions.
One of the most notable near-miss collisions happened in 2019 between an ESA satellite, and Elon Musk’s SpaceX’s Starlink Satellite. After this occurred, the ESA tweeted out a complaint about having to move their satellite in order to avoid the Stalking satellite.
It was the first time that Europe’s Space Agency had had to move a satellite to avoid a satellite associated with a broadband mega constellation.
Though it doesn’t happen very frequently, it is possible for satellites to crash into each other, when they drift into each other’s orbit by accident.
There are measures in place to stop satellites from colliding in space – such as launching them into their own specific free orbit and having teams of people controlling them down on earth.
However, slip-ups do happen, and sometimes it is unavoidable – which can lead to the loss of billions of dollars with of tech, scientific data, and even impact things like communication down here on earth.
As the amount of space junk increases, which is cluttering up orbit paths around the earth, it is more likely that we will hear about more and more incidents of satellite crashes and collisions.
Until there are laws forcing companies and space agencies to de-orbit their defunct satellites, this will become a bigger problem as years go by.