Since the 1950s, our planet has sent many things into space such as rockets, shuttles, people, animals and satellites – even ashes of loved ones!
The thing is, eventually – these items end up as “space junk”, and people often wonder what happens to this. Do they ever come back to Earth?
With so many of us enjoying satellite technology for entertainment and communication, plenty of satellites have been sent into Earth’s orbit and over time – they die. With this in mind, many have questioned if a dead satellite will fall back to Earth.
So, we’ve decided to answer all of your questions and more below.
What Is A Satellite?
A satellite is the general term for an object that orbits around a different, larger object. How we normally understand a satellite though is from the man-made satellite – which are used for plenty of reasons including space photography, telephone connections and television signal transfer.
Satellite technology can help us communicate much further around the world than we used to be able to and watch television shows that span the Earth. They can also assist space researchers to understand the wider universe and how it works, using photography.
The Soviet Union sent the first satellite into space in 1957, followed by the US a year later. Many people have asked over the coming years if a satellite can crash into another satellite.
The answer to this is, the chances of a crash is rare – but they increase with every satellite that is placed into Earth’s orbit. They are specifically designed and placed into orbit to avoid a collision in space – but it has happened.
In 2009, 2 satellites crashed into one another, and to our knowledge – this was the first time this has happened but a similar event happened after. In 2021, a Chinese satellite crashed and broke up after colliding with part of a Russian rocket!
How Do Satellites Stay In Space?
Satellites are effectively placed into orbit by us, using a rocket that travels at 25,000 miles per hour and dropped into orbit. They end up stuck at a speed that is quick enough to bypass the pull of gravity to the Earth. This immense speed is large enough that the satellites have potential to remain in Earth’s orbit for hundreds of years.
The way that a satellite can keep in orbit is by a specific balance of Earth’s gravitational pull and the velocity it has (speed traveling). They have their own fuel source but they do not need this to continue moving, they need it to either change their orbit or to move out of the way of potential collisions.
What Happens To Dead Satellites?
Nothing lasts forever and satellites – although they have a long life – eventually will die. Just like an old washing machine or coffee maker, the time will come when a satellite will need to be replaced due to poor functionality.
It does not matter what the purpose of the satellite is either. If it is for the use of telephone communications, television signals or to monitor greenhouse gas emissions from the Earth – all satellites will succumb to their own demise.
When their day comes, we have a choice of two options for what to do with them. The first option applies to satellites that are closer to Earth. The engineers will monitor the satellite and allow it to run its last bit of fuel until it dies completely. It will then fall out of orbit and burn up on its fall to Earth’s atmosphere.
The second option is much more costly and more complicated. As these satellites are further from the Earth, it will take more fuel to bring the satellite closer to Earth’s atmosphere and allow it to burn up that way, so we decide to send the satellite much further into space away from Earth.
Do Satellites Ever Fall To Earth Entirely?
Although it is possible, the likelihood of this happening is incredibly low for a normal satellite. However, larger items that do not fully burn up in our atmosphere on the way to Earth can indeed fall to Earth.
An example of this is from 2018, when the Tiangong Space Station was due to fall. Scientists and Government agencies for a long time had kept an eye on this as to when it would fall. Eventually it did and landed safely, in what we refer to as the “space cemetery”.
Operators of spacecrafts will plan carefully as to where these space objects will fall when they head to Earth, and the safest place is in the South Pacific Ocean, due to how vast it is and away from more land.
You might be wondering after hearing about the space cemetery – what happens to those satellites that we blast much further away from the Earth. They are effectively sent into what is called a “graveyard orbit”, which is over 200 miles away from any of our satellites in orbit. In fact, it’s over 22 thousand miles above the Earth.
We are in no danger of these coming back to Earth anytime soon as they are in a new orbit. However, over time as space travel advances – we may send crews to collect them out of space, but there are no plans for this currently.
What About Other Space Junk?
Space debris, or space junk as we call it, refers to the things that humans have left in space. This includes things such as satellites, parts of rockets that break away or even items we have left from space missions.
It’s estimated that along with our 2000 satellites that are live and orbiting the Earth, there are at least 3000 dead ones. There are additionally 34 thousand items of space junk that are much larger than satellites and can prove to be more dangerous if they fall out of orbit or collide with other things.
Does Space Junk Cause A Problem Or Risk To Space Exploration?
Luckily for us, there have been no reported cases of astronauts or cosmonauts having problems with space junk whilst working or exploring space.
Satellites, as we have said, are designed to avoid collisions anyway – so the likelihood is that they will move and change their directions if a mission is on its way toward a satellite. Interestingly, this maneuvering also occurs with the International Space Station – perhaps more important when there are people on board!
There is a dedicated team to space debris and they monitor old satellites and other pieces of space junk to ensure public safety and the safety of any workers in space if a crash were to occur.
The Numbers At A Glance
It’s perhaps easier if we begin to summarize the numbers:
- 5000 satellites (2000 live and 3000 dead)
- 34,000 large pieces of space junk
- 128 million smaller pieces of space junk
- A risk of collision in space is 1 in 10,000
- The International Space Station has avoided 25 collisions with debris since 1999
Satellites can fall back to Earth but the easiest way to explain it is through size. Smaller items from space will burn up in our atmosphere and pose no threat, whereas larger items will require plans to try and mitigate the issues – normally this is planned so they land in the South Pacific Ocean.
- I Can’t See Anything Clearly Through My Telescope – Help! - April 26, 2022
- Astronomy For Beginners – Getting Started Stargazing! - April 26, 2022
- Are Telescopes Easy To Use? - April 26, 2022