Stilsat-1: a Chinese-built Russian satellite watching Ukraine

[B. Hendrickx]

https://www.thespacereview.com/article/5095/1

Stilsat-1: A Russian-owned and Chinese-built satellite watching Ukraine (part 1)

A satellite owned and operated by Russia has been snapping high-resolution images of Earth since last year, mainly to support the country’s war effort in Ukraine. The Russians call it Stilsat-1, but no satellite by that name has been officially announced as such after launch or registered with the United Nations. The reason is that it was built and launched by China and turned over to Russia on a turnkey basis. Although Russian officials have quietly acknowledged this, they have provided conflicting information on the satellite’s design and not revealed its exact launch date or its official Chinese name. Clearly, the need to purchase an observation satellite abroad is considered an embarrassing fact which exposes shortcomings in Russia’s satellite production capabilities and its own satellite coverage of the war zone in Ukraine.

Stilsat-1 is seen as a technology demonstrator for future Stilsat satellites, which will be built by Russia itself and inherit the Chinese optical system. Despite convincing evidence to the contrary, both the Kremlin and China’s Ministry of Foreign Affairs have recently denied allegations of high-level cooperation between Russia and China in obtaining satellite imagery of the battlefield in Ukraine. 

The satellite is named after Stilsoft, a Russian private company based in Stavropol that is in charge of the project. It specializes mainly in surveillance systems for round-the-clock monitoring of border areas and military sites, its main clients being organizations like the Ministry of Defense and the Federal Security Service (FSB). It started working on remote sensing satellites in early 2022, not coincidentally around the time of Russia’s large-scale invasion of Ukraine. In order to speed up the delivery of high-resolution imagery, it was decided to purchase a satellite from China that could be launched at relatively short notice. Later Stilsat satellites should be assembled by Stilsoft itself, but will still use Chinese optics. All this is not just speculation. During a handful of presentations that are openly available online, Stilsoft officials have been unusually loose-lipped about the project’s origins and key objectives and on two occasions even had to be interrupted by event moderators before going into further detail. 

Stilsoft has created a smokescreen around the project by giving contradictory information on the launch date and the design of the satellite. Putting together all the available information, the most plausible conclusion is that Stilsat-1 is the satellite launched by China under the name Taijing-3-02 in January 2024. Manufactured by Beijing-based MinoSpace, it has characteristics similar to those announced for Stilsat-1 and also resembles one of several designs presented for Stilsat-1. While this looks like the satellite purchased and operated by Russia, there are indications that Stilsoft may also be receiving high-resolution imagery from two other MinoSpace satellites, namely Taijing-3-01 (launched in February 2022) and Taijing-3-04 (launched in May 2025). To complicate the picture even further, Stilsoft has also been using the name Stilsat-1 for what look like one or more smaller imaging satellites with lower resolution that may or may not have been launched into space.

This is just an initial attempt to unravel the true identity (or identities) of Stilsat-1 based on currently available information. It’s an ongoing detective story and not all the conclusions may eventually turn out to be correct.

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AI enhanced

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Drawing (AI generated)

[B. Hendrickx]

Thanks for the enhanced illustrations. By the way, this drawing is illustrative of the misleading information that Stilsoft has been spreading about Stilsat-1. It was shown in Stilsoft presentations in October and November 2023. In the November presentation it was identified as Stilsat-1 (which is the Chinese-built satellite) and in the October presentation as the serially produced Russian version of Stilsat (which will be introduced with Stilsat-2 and have a Russian-built bus with the Chinese optical payload).

However, in the November presentation, the Stilsoft official also showed another design (with a hexagonal bus) that he called the serially produced version, so I’m fairly confident the one seen here is Stilsat-1. It corresponds quite nicely to an illustration of MinoSpace’s MN-200 bus, which is used by Taijing-3-01, 3-02 and 3-04.  The frame surrounding the telescope is not seen in pictures of the actual satellites, but could be under the thermal insulation.

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However, in the November presentation, the Stilsoft official also showed another design (with a hexagonal bus)

[B. Hendrickx]

Part 2 of the article is now up on The Space Review:
https://www.thespacereview.com/article/5099/1

It examines the Russian version of Stilsat, which will be introduced with Stilsat-2. It consists of a Russian-made bus and the same Chinese optical system currently being flown on Stilsat-1. The ultimate goal is for the production of the optical system to be transferred to Russia as well, where it will be built on the basis of Chinese blueprints. The Russian version of Stilsat appears to be the one that is shown to have a hexagonal bus. Initially, it had two solar panels, but in later illustrations it is depicted with three solar panels.

Stilsoft’s plan is to operate a constellation of nine Stilsat satellites spread over three orbital planes. The launches of the follow-on Stilsat satellites have slipped considerably in recent months. According to Stilspace’s website, they will now take place between the second quarter of 2027 and the fourth quarter of 2033.

Confusingly, a satellite looking exactly like Stilsat has recently surfaced under the name KOEN, the Russian abbreviation for “Electro-Optical Observation Complex”. While Stilsoft is still in charge of development, the operator is reported to be a start-up called MT-LAB (instead of Stilsoft’s subsidiary Stilspace) and a dynamic model has undergone testing at the Progress Rocket and Space Center (instead of Stilsoft’s own production facilities). The first KOEN launch is reportedly scheduled for next year, conflicting with the late 2027 launch date for Stilsat-2 given on Stilspace’s website. The goals for KOEN are the same as those given for Stilsat, including some that can be linked to the war in Ukraine. Whether future Stilsat satellites will still focus on Ukraine will, of course, depend on how much longer the conflict drags on.

Part 2 also looks at other deals that Russian private companies have signed in the past three years with Chinese operators of remote sensing satellites to provide imagery of the war zone in Ukraine. One prominent user of Chinese remote sensing data was Yevgeni Prigozhin’s Wagner Group, which was active on the battlefield until its short-lived rebellion in June 2023. 

Both the Kremlin and the Chinese Ministry of Foreign Affairs have recently denied new allegations of high-level cooperation between China and Russia in obtaining satellite imagery of Ukraine, but there is overwhelming evidence to the contrary. So far, none of the criticism has specifically focused on the Stilsat project, even though its Chinese connection and its direct link to the war in Ukraine can be gleaned from open sources of information. Without a doubt, it represents the highest level of cooperation between Russia and China in the field of satellite remote sensing to date.

That cooperation is obviously needed because of shortcomings in Russia’s own satellite coverage of Ukraine. Part 2 concludes with a look at the current status of Russia’s reconnaissance satellite program. Although Razdan and Razbeg have most likely not yet flown, Russia has launched a number of low-orbiting military satellites in the last four years that are most likely used for optical reconnaissance, but cannot yet be linked to any known projects. These are twelve relatively lightweight satellites in the EO MKA/OO MKA series and a heavier satellite announced as Kosmos-2572.

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