Blue Marble image of the Earth taken by the crew of Apollo 17 on Dec. 7 1972.
Image Credit: NASA

We’re focusing specifically on the current active Earth Observation (EO) satellites in 2022 this week, following our wider look at satellites orbiting the planet last week.

Using the latest update of the Union of Concerned Scientists (UCS) satellite database, which lists the operational satellites in orbit on the 31st December 2021. As we saw last week it indicated that there were 1,052 active on that date which had the main purpose of EO and/or Earth Science.

According to the UCS, there were 971 EO satellites in orbit on the 30^th April, meaning an 8.34% increase in eight months. Whilst the number of EO satellites in space continues to grow, their rate of growth has been overtaken by satellites for space-based broadband.

What do Earth observation satellites do?

Whilst the 1,052 satellites we are looking at have a purpose of EO or Earth Science, there are further details on their specific roles, which shows that there are:

• Optical Imaging: 426 satellites.
• Meteorology: 170 satellites.
• Electronic intelligence: 113 satellites.
• Radar imaging: 90 satellites.
• Earth Observation: 79 satellites (no detailed purpose listed).
• Earth Science: 75 satellites.
• Hyperspectral/Multispectral imaging: 41 satellites.
• Automatic Identification System (AIS): 19 satellites.
• Other purposes: 17 satellites.
• Infrared imaging: 12 satellites.
• Video: 10 satellites.

Optical imagery is still the largest type of EO satellite in orbit, representing just over 40% of the fleet. Meteorology represents just over 16%, Electronic Intelligence almost 11% and Radar imaging 8.5%. Note that some satellites have multiple purposes.

Who controls the EO satellites?

There are 219 organisations registered as operating EO, although 115 of these only operate one satellite; another 41 organisations operate two satellites, 12 operate three satellites and 9 operate four. Whereas the top operators control almost 55% of the world’s active EO satellites, and these operators are:

1. Planet Labs Inc with 188 satellites.
2. Spire Global Inc with 119 satellites
3. Chinese Ministry of National Defense with 85 satellites
4. America’s National Reconnaissance Office (NRO) with 44 satellites
5. Chang Guang Satellite Technology Co. Ltd. With 29 satellites
6. Russia’s Ministry of Defense with 21 satellites.
7. Satellogic S.A. with 20 satellites.
8. 17 satellites are operated by both:
   • China National Academy of Sciences (CNSAS), and
   • Indian Space Research Organization (ISRO)
9. 12 Satellites are operated by:
   • BlackSky Global
   • EUMETSAT (European Organization for the Exploitation of Meteorological Satellites)
   • ICEYE Ltd.

There are a number of commercial companies in the top operators’ list:

• Planet, Spire Global, & BlackSky Global are American companies.
• Chang Guang Satellite Technology Company is a Chinese company.
• Satellogic is an Argentinean company
• ICEYE ltd is a Finish company.

Countries with the most Earth observation satellites

Given the list of the top organisations that operate satellites, it is not that surprising the USA is way out in front, operating almost 43% of the world’s EO satellites, and it is also unsurprising that China is second with almost 25%. Between China and the USA, they operate 712 of the 1,052 EO satellites, equivalent to two thirds.

70 individual countries are listed in the database as controlling EO satellites, although 59 of these countries operate less than 10 satellites. The countries that operate more than 10 are:

• USA with 451 satellites.
• China with 261 satellites.
• Russia with 37 satellites
• Japan with 35 satellites.
• India with 23 satellites.
• Argentina with 22 satellites.
• European Space Agency with 20 satellites (although it is acknowledged that this is a multi-country operation, rather than a single country).
• France with 15 satellites
• Finland with 13 satellites
• Germany with 11 satellites.
• Taiwan/USA jointly operate 11 satellites.

Who uses the Earth observation satellites?

The users for the EO satellites listed by the UCS are:

• 495 satellites are listed as having Commercial users.
• 310 satellites are listed as having Government users.
• 220 satellites are listed as having Military users.
• 27 satellites are listed as having Civil users.

It should be noted that some of these satellites have multiple users.

What are the orbits of the Earth observation satellites?

Of the satellites in orbit:

• 989 are in Low Earth Orbits (LEO) equating to 94.01% of the EO satellites.
• 46 are in Geostationary Earth Orbits (GEO) – 4.37%.
• 1 is in a Medium Earth Orbits (MEO) – 0.09%.
• 16 are in elliptical orbits – 1.52%.

What’s next?

Although the growth of EO satellites has slowed down over recent years, there is still growth in terms of hyperspectral, Radar and video satellites and constellations of these satellites are expected to become more prominent in coming years. All of this means that the amount of EO data available will continue to expand!