How many satellites are orbiting the Earth in 2018?

Image courtesy of ESA
Note: The debris field shown in the image is an artist’s impression based on actual data. However, the debris objects are shown at an exaggerated size to make them visible at the scale shown

This is our annual update on the satellites currently orbiting the Earth.

How many satellites are orbiting the Earth?
According to the Index of Objects Launched into Outer Space maintained by the United Nations Office for Outer Space Affairs (UNOOSA), there are 4 857 satellites currently orbiting the planet; an increase of 4.79% compared to last year.

So far in 2018, UNOOSA has recorded 204 objects launched into space. This is already more launches than was achieved in any entire year before 2013, and very close to the number of launches in 2013, 2014, 2105 and 2016. However, it did not beat last year as 2017 was a bit of a record breaker! There were 453 objects launched last year alone, which equates to over 5% of the objects ever launched into space!

A significant proportion of the 453 were cubesats for Earth Observation or communication purposes, and it is these smaller satellites that are driving the increase in objects being put into space. According to UNOOSA, in history 8 126 objects have been launched into space, and over 22% of these are within the last eight years alone. Both technology developments and improved interest in space, particularly from start-up companies, are behind the recent drive.

How many of these orbiting satellites are working?
The Union of Concerned Scientists (UCS) keeps a record of the operational satellites and their latest update records details to the end of April 2018. Using this database together with the UNOOSA Index shows that there are currently 1 980 active satellites in orbit. Whilst this is 13.92% increase over the number of active satellites last year, it still represents only 40% of the satellites orbiting the planet.

This means that there are 2 877 pieces of useless metal hurtling around the Earth at high speed! Interestingly this is actually 20 less than when we did the 2017 update, meaning a number of inactive satellites either deorbited and came back to Earth or burnt up in the atmosphere.  This is not as rare as you might think, as one average about one satellite a week returns to Earth in one form or another.

According to the UCS database of the 453 objects launched in 2017 only 390 of them were still in space at the end of the April 2018. 14% had already returned to Earth, of course some may have been brought back due to to malfunctions, but a lot of the small satellites only have short lifespans and could have already completed their missions.

What are all these satellites doing?
Using the UCS update as at the end of April, the main purposes for the operational satellites are:

  • Communications: 792 satellites, a 6.7% increase on last year.
  • Earth observation: 661 satellites, a 10.9% increase on last year.
  • Technology development/demonstration: 213 satellites, a 10.4% increase on last year.
  • Navigation/Positioning: 121 satellites, a 12% increase on last year.
  • Space science/observation: 76 satellites which is no real change from last year.
  • Earth science: 23 satellites, which is no real change from last year.

Although, it should be noted that some of the satellites have multiple purposes. We’ll examine the Earth observation category in more detail in a future blog.

Who uses the satellites?
The four categories of users in the previous section shows that:

  • 826 satellites are listed as having commercial uses
  • 523 with government uses
  • 399 with military user; and
  • 138 with civil uses

It should be noted that 278 satellites (14.6%) are listed as having multiple uses.

Which countries have launched/operate satellites?
According to UNOOSA 81 countries have launched satellites, although this is slightly complicated by the fact that satellites are also launched by institutions and organisations such as the European Space Agency.

Looking at the UCS database, there are 65 countries listed as currently operating satellites, although there are 65 satellites simply listed as having multinational operators. There is an interesting infographic on the UCS site showing the change in countries operating satellites between 1966 and 2016.

In terms of countries with the most satellites the USA significantly leads the way with 859 satellites, China is second with 250, and Russia third with 146. These are then followed by Japan (72), India (55) and the UK (52).

What types of orbits are the satellites in?
For the current active satellites:

  • 2.1% are in Elliptical orbits which vary between less than 1 000 km to above 40 000 km above the Earth.
  • 29.1% are in Geostationary Earth Orbits (GEO) which is just under 36 000 km above the Earth.
  • 5.9% are In Medium Earth Orbits which are anything between 8,000 km and 24,000 km above the Earth.
  • 62.9% are in Low Earth Orbits (LEO) which varying between 250 km and 1 500 km above the Earth; and of these LEO’s (although 12 – 1.01% – have no track listed):
    • 57.5% are in sun-synchronous orbits which means they pass the equator at the same time each day.
    • 22.85% are in non-polar inclined orbits.
    • 16.1% are in polar inclined orbits.
    • 1.69% are in equatorial orbits
    • 0.76% are in elliptical orbits.
    • 0.08% (Actually, just 1 satellite) is in a cislunar orbit.

Remember ….

When you gaze up at the stars, there are thousands of active, and inactive, satellites also up there and their numbers are on the increase.

19 thoughts on “How many satellites are orbiting the Earth in 2018?

  1. It seems Very excessive to keep placing short-term satellites around our planet, for people to tell each other what they had for dinner or breakfast or to have a social say. This is the final frontier we haven’t totally screwed up as yet but we’re getting there fast. There’s already far too much junk around us now – we need to stop & think – not use more. Please look around us for things to do before looking outward any further, or creating another issue for our children worldwide…

    • Hi John,

      We’re equally concerned about the issue of space junk, as are many others around the world. There are now some satellites being launched to try and attempt to undertake debris removal. However, like a lot of the pollution issues the Earth, it’s not going be an easy one to resolve. Positive steps are being taken, but there is a long way to go.

  2. I wonder if the almost 5000 artificial satellites currently orbiting our planet, are interrupting the natural gravitational relationship between the moon and Earth, causing the unusual weather conditions. Perhaps this is not a global “warming” thing. Perhaps it’s a gravity thing.

    • We’re not gravity experts, as we deal with the data the satellites collect, but due to the limited mass of the satellites when compared to Earth and the fact that the satellites, and associated debris, are spread out around the planet, our view is that any impact on the gravitational relationship is likely to be negligible.

    • These objects do not have a mass that can cause that phenomena, even if all were concentrated in one solid object.

  3. Is there any Environmental Contribution when satellites to launch in orbits? I think they should pay the cost for sweeping the orbit which will make help removing potential space debris. All of the satellites have the potential to be space debris. We need international funds.

    • There is a requirement now for most satellites launching that they had end-of-life disposal arrangements, which generally means that they are either brought back to Earth for larger satellites or they burn up in the atmosphere for the small ones. However, we’re not aware any overarching environmental fund contribution to removing debris. We’d agree it is an issue, and whilst there are some missions that are starting to look at debris removal, there is a huge amount of debris of all sizes already up there, and operating satellites that could become future debris.

  4. Do these counts include military/spy satellites? How often(if ever) does space debris and/or satellites collide? Russia has the ability to jam GPS signals apparently, is this done at the satellite level? Where can I find info on satellite treaties/agreements between nations? Great blog. Thanks.

    • Thanks for the questions and for reading the blog.
      The counts do include military/spy satellites – as far as we can be sure! The military numbers of the blog are generally satellites that are controlled by a military force, we would assume that a lot of these are either spy or communication satellites – however very little more is known about these for obvious reasons. Generally, it is difficult to launch satellites without someone spotting it, and so the figures are fairly accurate – of course it’s always possible that someone managed to launch without it being noticed, but I would think it was fairly unlikely.
      Satellites do get hit by debris, for example, this blog describes when Sentinel-1A was hit, and here we have a bit more about the debris. Satellites also perform manoeuvres to avoid debris which reduces the collisions.
      Details on space treaties are dealt with by the United Nations Office of Outer Space Affairs as they tend to be international ones, rather than between individual countries.
      Hope this helps.

    • That’s a very good question. The best list of currently active Earth Observation satellites we know about are:
      Oscar website (Observing Systems Capability Analysis and Review Tool) which has keeps track of all satellites launched, or planned to launch, in its space capabilities section. There is an option to filter only currently operation ones which will give you the list you are looking for, and you can export the data.
      CEOS website (Committee on Earth Observation Satellites) has an online database of Earth Observation missions, instruments, etc. Again this is downloadable.
      The Union of Concern Scientists also have a downloadable database of active satellites which you can filter on Earth Observation – it has a slightly different information to Oscar. It’s a great resource, but it is only at a point in time with the last updated at the end of April this year.
      These are the best example we know, but we’ve never confirmed how complete either are or how quickly they are updated.
      Hope this helps.

  5. I was just wondering if some type of ballistic approach could work? All you would need to do is cause a degrading orbit so in theory couldn’t a gun in space work? Fire a shot at a satellite from another satellite and cause degrading orbit. It would then just burn up right?

    • Firstly, space is considered to be a peaceful domain, and weapons generally aren’t used. The major danger of this solution would be the creation of space debris, even tiny pieces of around 1 cm travelling at high speed can cause damage to other satellites. In 2007 China used an anti-satellite missile to destroyed one of it’s own satellites and this created 3 000 pieces of space debris, the majority of which are still in orbit. Until the creation of new debris could be eradicated, then this solution is unlikely to be helpful.

    • Simply, because some countries use the comma to indicate a decimal point in numbers, and as we have an international readership we felt that this would be the best way of ensuring no confusion occurs.

  6. this is very great information thank you so much this site got me to finish my science project of school thank you so much

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