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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 update on the satellites currently orbiting the Earth as at the 31^st March 2020. According to the Index of Objects Launched into Outer Space, maintained by the United Nations Office for Outer Space Affairs (UNOOSA), there were 5 774 individual satellites in space at the end of March this year; an increase of 15.78% compared to the start of 2019. This is a significant increase in fifteen months.

UNOOSA recorded that 580 objects were launched into space during 2019, this is the largest annual number ever recorded. It is almost 30% more than occurred in each of the previous two years. However, that record number is very likely to be smashed in 2020 as by the end of March there had already been 356 launches! A further 74 have been launched from the start of April until the middle of May, giving 430 launches so far in 2020. Given that the global pandemic has already had an impact on a number of launches, without we’d already have been closing on the five hundred and we are not even halfway through the year yet.

The growth of objects in space

We realise these are just numbers, but to understand how truly exponential this growth in satellites orbiting the Earth really is, you need to look at the history human space launches. The first-ever object launched into space was SPUTNIK-1 on the 4^th October 1957, and in the sixty-three years since we’ve been able to do this, according to UNOOSA, there have been 9 456 objects ever launched into space. However, over 20% of these objects – 1 919 in number – have been launched in the last three years and three months alone. This is a phenomenal level of growth. The shocking things is, that this is nothing compared to what’s to come.

The growth of the satellites over the last decade was driven by the development of the CubeSat, and the large number of new Earth Observation satellite constellations, like those owned by Planet. However, the new growth spurt is being driven by satellite internet from the likes of SpaceX and OneWeb are leading this drive, although there are others planned too, who between are hoping to launch tens of thousands of satellites in coming months. Obviously, OneWeb recently went into administration and it’s not currently clear what is happening with their ambitions.

All of the orbiting satellites are working, aren’t they?

You’d expect that most of the satellites would be operational wouldn’t you? Well, you might be surprised at the answer.

The Union of Concerned Scientists (UCS) keeps a record of the operational satellites and their latest update provides details to the end of March 2020. Using this database together with the UNOOSA Index shows that there are currently 2 666 active satellites in orbit around the Earth, which represents approximately 46% of the 5 774 objects in space, and increase on the 40% figure 15 months ago. It should be noted that they are a handful of satellites orbiting other planets, moons or asteroids.

In effect, this means that there are 3 108 hunks of metal flying around the Earth at thousands of miles per hour doing absolutely nothing.

What are all these satellites doing?

Using the UCS update, as at the end of March, the main purposes for the operational satellites are:

• Communications: 1 211 satellites – increase of 55% since the start of 2019.
• Earth observation: 884 satellites – increase of 24.5% since the start of 2019.
• Technology development/demonstration: 312 satellites – increase of 40% since the start of 2019.
• Navigation/Positioning: 148 satellites – increase of 8% since the start of 2019.
• Space science/observation: 93 satellites– increase of 9% since the start of 2019.
• Earth science: 18 satellites – a decrease of 28% since the start of 2019.

Although, it should be noted that some of the satellites have multiple purposes.

Who has the most satellites?

According to the UCS database, the top five countries with the most operational satellites are:

1. USA
2. China
3. Russia
4. United Kingdom
5. Japan

It’s also interesting to look at who operates the most satellites, which are:

1. SpaceX – 358 satellites. These are the Starlink satellite internet constellations, owned by Elon Musk’s American company.
2. Planet Labs – 246 satellites. These are Earth Observation satellites for this American company, the majority of which are the Dove CubeSats.
3. Russian Ministry of Defence – 97 satellites. Combination of satellites for Communication, Earth Observation and Navigation.
4. Spire Global – 89 satellites. These are Earth Observation satellites for this American company that are further defined as delivering Meteorology and Automatic Identification System (AIS) data.
5. Iridium Communications – 78 satellites. These are communications satellites for this American based company.
6. OneWeb – 74 satellites. OneWeb’s satellite internet constellation. This was a UK based company, but it recently went into administration.
7. China’s People’s Liberation Army – 68 satellites. These are mostly recorded as Earth Observation satellites.
8. Chinese Defense Ministry – 49 satellites. These are recorded as Navigation and Global Positioning Satellites.
9. SES SA – 48 satellites. These are communications satellites for a commercial company based in Luxembourg.
10. Indian Space Research Organisation (ISRO) – 45 satellites. This is India’s national space organisation, and they have orbiting satellites undertaking a wide range of roles include Communication, Earth Observation, Navigation and Positioning, Space Science & Technology Development.

Who are the users of the satellites?

Given the number of commercial satellite owners in the list of the top ten, it’s probably no surprise that looking at the primary users gives:

• 1,454 satellites are listed as having commercial users
• 599 with government users
• 477 with military users; and
• 136 with civil users.

It should be noted this list is the primary user of the satellite, of these there are 318 satellites (11.93%) which listed as having multiple users.

When you look up at the night sky ….

Remember that there are thousands of objects orbiting the planet. The orbits of these are:

• 1,918 in a Low Earth Orbit.
• 137 in a Medium Earth Orbit
• 554 in a Geosynchronous Equatorial Orbit, also known as a geostationary orbit.
• 57 in an Elliptical Orbit.

Interestingly, if you look carefully, it is possible to see some of these objects from Earth with the naked eye. Famously, it is possible to see the International Space Station and these days it is also possible to see the Starlink constellations. So when you look up at the stars and see the bright objects moving across the sky it could be a satellite!