Russia launches new-generation military satellite

A long-delayed spacecraft believed to be capable of guiding Russian Navy missiles to their targets reached orbit. The liftoff of a Soyuz-2-1b rocket with the Pion-NKS radar-carrying satellite took place as scheduled on June 25, 2021, at 22:50 Moscow Time (3:50 p.m. EDT) from Plesetsk Cosmodrome, north of Moscow.

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First Pion mission at a glance:

Spacecraft designation
Pion-NKS, 14F139 No. 901, Kosmos-2550
Launch vehicle Soyuz-2-1b
Launch site Plesetsk, Site 43, Pad 4
Launch date 2021 June 25, 22:50:00.241 Moscow Time
Mission Electronic intelligence and radar imaging for the Liana network
Customer Russian Ministry of Defense
Spacecraft development KB Arsenal, RKTs Progress
Payload prime developer Berg TsNIIRTI Institute
Orbit 500 kilometers, inclination 67 degrees
Spacecraft mass 6.5 tons
Operational life span 4-5 years

What is Pion-NKS

The Pion-NKS satellites were built as part of the Liana electronic-intelligence network operated by the Russian military and serving both ground forces and the Navy. As of 2021, the constellation had seen the launches of five Lotos spacecraft equipped with radio-intercept sensors. However, the upcoming mission should introduce a major new capability to the system adding an imaging radar intended for pinpointing potential targets around the world for the Russian Navy independent of weather and lighting conditions. The combined system, including the Pion (peony) and Lotos spacecraft, along with their ground assets, has the technical designation 14K160.

In active development since 1993s, the Pion-NKS (14F139) spacecraft should fully replace the capabilities of the currently retired US-A and US-PU satellites, which had provided electronic intelligence and target guidance since the Soviet period. They were developed at the KB Arsenal design bureau in St Petersburg, which also served as system integrator for Lotos and Pion satellites.

Pion and Lotos share a common satellite platform developed at RKTs Progress in Samara and based on the company's long-running Kobalt spy satellite series. However, while Lotos first reached orbit in 2009, the Pion sub-system remained grounded for another decade due to problems with the development of its main payload at the Berg Institute, TsNIIRTI, specialized in electronic warfare. While TsNIIRTI served as the prime integrator of the payload, its overall development was assigned to St. Petersburg-based NII Vektor specialized in military radio systems. (366)

The most critical and most technically problematic component of the payload was a dual imaging radar developed at Vega Corporation, which had previously supplied similar payloads for the Soviet Almaz and Priroda spacecraft, as well as to the Russian Kondor satellites. The radar aboard Pion-NKS was apparently intended primarily for imaging sea vessels. Operating in concert with radio-intercepting sensors, the radar would greatly enhance the locating and identification of sea-based targets.

In 2013, at the Moscow air and space show, KB Arsenal presented scale models and technical specifications of several spacecraft including the Ficus satellite, which closely resembled the Pion-NKS satellites, but was marketed for commercial remote-sensing applications. According to the company, the spacecraft would be equipped with a synthetic aperture radar operating in three frequency bands. With each of its two antennas covering a swath of 500 kilometers on the Earth's surface, the instrument would be capable of producing images with a resolution between 1 and 1.5 meters, provide elevation data for three-dimensional topographic maps, discriminate between vegetation and other surfaces and visualize sub-surface features. The data from the instrument would be processed aboard the satellite, the company's leaflet said.


KB Arsenal listed following specifications of the Fikus satellite:

Liftoff mass 6,250 kilograms
Orbital altitude
500 kilometers
Orbital inclination 84 degrees
Orbital period 94.47 minutes
Maximum observation time per orbit 30-35 minutes
Attitude control accuracy No more than 16 angular minutes
Reliability 0.9
Operational life span 7 years
Imaging radar wavelength 9.5, 23.5, 65 centimeters
Swath 2 x 500 kilometers
Image resolution in survey mode 100 meters
Image resolution in detail mode 5 meters
Antenna dimensions 12 by 4 meters

Development problems

According to the Russian press, the breakdown of industrial cooperation with Ukraine in 2014 and the subsequent western sanctions played a role in the severe delay of the Pion-NKS project.

In 2014, in parallel with the completion of the second Lotos satellite, KB Arsenal was already preparing the launch of the first Pion-NKS spacecraft. At the time, the company was assembling the satellite platform and had also initiated experimental testing of its payload. However, according to unofficial reports, the most critical component of the satellite's payload, most likely its radar, was missing.

According to the design bureau at the time, the first Pion-NKS would certainly fly in 2015, but at the beginning of that year, the head of space projects at KB Arsenal, A. V. Ivanov only mentioned electric and radio tests of the Pion-NKS spacecraft among the organization's planned activities in 2015, even though another official at MZ Arsenal (which serves as the assembly plant for the design bureau), said that all components of the satellite had been delivered.

At the same time, Ivanov disclosed that KB Arsenal had gotten a contract for a new-generation spacecraft, which was then in the preliminary design phase.

Still, it was only in September 2018, during a meeting of the Russia's military collegium, that Defense Minister Sergei Shoigu confirmed signing the integrated development and production schedule for the Pion-NKS satellite. In the subsequent public statements, the Russian military characterized the system as strategically important, but the Ministry of Defense had hinted the project faced multiple delays. Shoigu even said he was taking the project "under his personal control." According to some rumors on the Russian Internet around that time, the launch of the first Pion-NKS was planned for the end of 2019.

However, in June 2020, Pion-NKS was still listed among "problematic issues" discussed at a meeting of top defense officials chaired by Shoigu. According to public announcements at the time, the "production completion schedule" for the first Pion-NKS satellite was signed at the end of 2019.

In early March 2020, Shoigu announced that the development of the Pion-NKS satellite had entered its final phase.

Pion's launch profile


In mid-June 2021, authorities in the Komi Republic informed the local population that a booster drop zone spanning the rural Ust-Tsilemsky and Izhemsky districts would be used for a Soyuz-2 rocket launch scheduled between June 25 and June 30, 2021. Representatives from the republic's environmental authorities and officials from the Plesetsk launch site were scheduled to overfly the area between 21 and 24 of June. The impact region, located around 650 kilometers downrange from Plesetsk appeared to be the same that had previously been reserved for the Lotos missions, targeting orbit with an inclination 67.1 degrees toward the Equator. That particular area would likely be used for dropping the two segments of the payload fairing separating during the operation of the rocket's second stage.

The four boosters of the first stage were expected to split from the core booster of the second stage around two minutes after the liftoff and impact the ground around 350 kilometers from the launch site. In turn, the second stage would normally operate until less than five minutes into the flight and then fall in the Yamalo-Nenetsky Autonomous Region, along with thre three fragments of the tail section of the third stage, which part with it just moments after the split with the second stage. Under normal conditions, the third stage of the rocket fires until nearly nine minutes into the flight, releasing its payload into an initial parking orbit. In the case of the Lotos and Pion missions, the satellites are then supposed to use their own propulsion systems to adjust the orbit to their operational altitude.

Around 10 minutes after the planned liftoff, the Russian Ministry of Defense confirmed that the Soyuz-2-1b rocket had lifted off from Pad 4 at Site 43 in Plesetsk on June 25, at 22:50 Moscow Time. The subsequent statements said that the assets of the Titov Chief Test Center had begun tracking the vehicle at 22:52 Moscow Time and that the new-generation military spacecraft had been delivered into the planned orbit. It received a public designation Kosmos-2550.

Multiple witnesses across Russia reported seeing the rocket moving across the white night summer skies and forming a characteristic "jellyfish" plume.

As with previous Lotos missions, the spacecraft was tracked in a 195 by 466-kilometer initial orbit with an inclination 67.1 degrees twaord the Equator. If everything went as planned, the spacecraft would fire its engine near apogee (the highest point) several days after launch to make the orbit circular at an altitude of around 500 kilometers.


To be continued


Page author: Anatoly Zak; last update: November 10, 2021

Page editor: Alain Chabot; last edit: June 25, 2021

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insider content



The Priroda module with its research radar antenna deployed onboard Mir. Pion-NKS is probably carries a similar antenna. Credit: NASA


This promotional image approximates the general architecture of the Pion navy electronic intelligence satellite. The actual vehicle carries not one but two radar antennas, as well as deployable panels with receiving sensors similar to those on the Lotos-S satellite (above). Credit: TsNIRTI


In 2013, KB Arsenal presented a scale model and technical description of the Fikus spacecraft, which was essentially a civilian version of the Pion-NKS satellite. Click to enlarge. Copyright © 2013 Anatoly Zak


Along with Fikus, KB Arsenal presented imagery of historic and proposed radar-carrying satellites, including an architecture equipped with a nuclear power source. Click to enlarge. Copyright © 2013 Anatoly Zak


Payload fairing of the first Pion-NKS mission. Click to enlarge. Credit: Russian Ministry of Defense


Soyuz-2-1b rocket lifts off on June 25, 2021. Click to enlarge. Credit: Russian Ministry of Defense


Pion-NKS spacecraft in folded position at separation from the launch vehicle. Click to enlarge. Credit: KB Arsenal


Click to enlarge. Credit: KB Arsenal


Artist renderings of Pion-NKS spacecraft published in 2021. Click to enlarge. Credit: KB Arsenal