The threat of Chinese and Russian space SIGINT satellites

The 2021 launch of a set of Yaogan-31 satellites, believed to be used for naval reconnaissance. (credit: CASC)

By Matthew Mowthorpe
Monday, July 22, 2024

China and Russia have extensive space-based targeting capabilities, which can geolocate transmissions from the radars of the UK and NATO allies’ navies. This tracking information is then linked to land-based and naval missiles to ensure they can target the UK and US navies.

China's space-based SIGINT capabilities

China has a SIGINT platform in geostationary orbit, which allows it to cover the hemisphere and remain persistently over one location. The first satellite in this constellation, Qianshao-3, was launched in 2015 and is estimated to be no longer operational. However, two other satellites were launched in 2019 and 2021. These satellites are in orbital positions over the Indian Ocean and Micronesia, as shown below. China is particularly concerned about naval activity in the Indian Ocean, as it perceives a threat from both the Indian and US navies, which are heading towards China from that direction.

This chart shows an estimated collection frequency range of 250 megahertz to 4 gigahertz. Interception of these frequencies enables geolocation by search radars, microwave communications, cellular communications, and L-band transmissions such as those from Inmarsat satellites.

Another series of SIGINT satellites is the Yaogan-31. This is a triple constellation that flies in close formation to provide precise geolocation accuracy. The table below shows the launch dates and how quickly China was able to populate the constellation.

This diagram shows the orbital formation of the YAOGAN-31 satellites. It has a lead, a trailing and an outlier satellite to provide precise geolocation of targets. The orbit inclination of 63.4 degrees allows for increased revisit time of Taiwan. Fountain.

In parallel, China launched the Yaogan-30 satellite constellation, which also consists of triplet SIGINT satellites, but at a lower inclination. The constellation includes 18 operational satellites. They do not fly very close together, but are spaced 120 degrees apart to provide greater coverage and geolocation capability. Yaogan-30 is similar to the Naval Ocean Surveillance System (NOSS) used by the US Navy. China likely copied the frequency collection range of the US NOSS satellites, which operated between 555 megahertz and 10 gigahertz with a geolocation accuracy of two to three kilometers.

The Yaogan-30 satellites are arranged in the same plane to improve the ability to track foreign naval deployments.

On September 10, 2023, Yaogan-40 01 A/B/C satellites, likely SIGINT spacecraft, were launched into an 847-kilometer orbit; C is now 787 kilometers away at the same 86-degree inclination. (Final Frontier Flash – 2023 – ISR University. They are in a precise triangular formation like the Yaogan-31 triplets. This indicates that this is a replacement for Yaogan-31 with two satellites maneuvering into higher orbits and the third in a lower orbit.

Russian space-based SIGINT satellites

Russia has been replacing its aging SIGINT satellite series. This includes the Lotos-S SIGINT satellite series, which is part of the ocean surveillance satellite system known as Liana. It has been operational since 2014. Liana provides SIGINT to the Russian Navy. Also included in this naval role is Pion. It was launched in 2021 after long delays from 2014 and provides synthetic aperture radar (SAR) satellite capability with SIGINT signals for the Russian Navy, as discussed below.

These are typical orbits for ELINT satellites used to detect radar emissions.

On June 25, 2021, Russia launched Pion. This is an ELINT and SAR imaging satellite capable of guiding Russian Navy missiles to their targets. It is part of the Liana system, operated by the ground and naval forces of the Russian military service. The SAR capability is primarily intended to obtain images of naval assets. It works in conjunction with ELINT sensors to locate and identify naval assets and uses SAR to obtain images of the identified asset. Pion will use its SIGINT capability to find a naval asset; once discovered, the SAR system will take an image. A SAR satellite alone would be unable to discover an asset.

This image shows the large SAR antennas combined with cross-shaped SIGINT capabilities, providing Russia with a powerful and unique space-based targeting capability.

In 2014, Russia launched a new series of geostationary orbit-based SIGINT satellites, similar to China's Qianshao-1 satellite series, providing long dwell times over a fixed point on Earth and hemispherical coverage. The Russian Olymp-1 satellite has a 15-year design lifespan, but has not changed position since summer 2022. This could indicate that it is low on fuel for maneuvers. Combined with the launch of Olymp-2 taking over Olymp-1's mission, it suggests that Olymp-1 is not operational. Olymp-2 was launched on March 13, 2023, and is moving around the GEO belt in close proximity to communications satellites. Olymp picks up C- and Ku-band communications.

This image shows the recent manoeuvres of Olymp-2 to track a Eutelsat communications satellite. It can carry out such proximity operations throughout its lifespan and intercept transmissions from other countries' communications satellites. Currently, other countries are unable to prevent Russia from carrying out such operations in space.

Conclusion

SIGINT satellite constellations provide Russia and China with a specific SIGINT detection capability. The table below is a summary of operational constellations that are capable of geolocating and targeting naval assets. While this capability is not limited to naval applications, both Russia and China use these systems primarily for naval applications because ground assets can be better geolocated using other ground assets.

Dr Matthew Mowthorpe currently works for BAE Space, where he manages space control as part of the Future Military Space programme. Prior to this he worked at the Ministry of Defence, where he led the space team examining threats to and from space. Dr Mowthorpe has published in numerous journals on the militarisation of space and most notably published the book Militarization and the militarization of space published by Rowman and Little in the USA.

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