Soyuz launches commercial satellite cluster

After a 48-hour delay by a technical problem, Russian personnel at Baikonur Cosmodrome, Kazakhstan, successfully launched a Soyuz-2-1a rocket on March 22, 2021, delivering the CAS-500-1 remote-sensing satellite for South Korea and 38 hitchhiker payloads from 18 countries in three different sun-synchronous orbits.




Soyuz rocket launch with the CAS-500-1 satellite at a glance:

Mission, payload CAS-500-1 and 38 secondary payloads
Launch date and time Originally: 2021 March 22, 09:07:12.770 Moscow Time
Spacecraft mass 2,200 kilograms
Launch vehicle Soyuz-2-1a No. V15000-044
Upper stage Fregat No. 122-05
Payload fairing 81KS No. V15000-057
Launch site Baikonur, Site 31
Target orbit Sun-synchronous

The "ridershare" mission

Roskosmos won the contract for the launch of two CAS-500 satellites in August 2017. The 500-kilogram spacecraft were developed at the Korean Aerospace Research Institute, KARI, for high-resolution multi-spectral imaging of the Earth's surface. The project, under development since 2015, was reported to cost $143.8 million.

The launch of the Soyuz-2-1a rocket with the CAS-500-1 satellite was originally planned in the third quarter of 2020. The preparation campaign was delegated to GK Launch Services, which was formed by Glavkosmos, a commercial subsidiary of Roskosmos State Corporation, and the Kosmotras company that had previously marketed discontinued Dnepr missions.

The remaining payload capacity aboard the Soyuz was marketed for the so-called "ridershare" mission, offering multiple customers to place hitchhiker payloads on the Fregat upper stage and release them in orbit after the separation of its primary passenger.

In the course of the mission planning and preparation, the exact number of booked passengers had changed, but according to a list issued by Glavkosmos around 10 days before the scheduled launch, a total of 38 secondary payloads from 18 different countries were onboard alongside the CAS-500-1. Seven spacecraft were classified as small satellites, 24 as cubesats and 6 as nanosats:

  • A dual ELSA-d (End of Life Service by Astroscale) satellite, was built by Astroscale Holdings Inc., which was founded in Japan in 2013. The pair, including the chaser satellite and a target, is scheduled to be released as a single 175-kilogram, 60 by 60 by 110-centimeter package. It is claimed to be the first spacecraft designed to demonstrate the core technologies necessary for space debris removal using magnets. The satellites were also reported to be propelled by environmentally friendly fuel, which will be used for proximity operations and the controlled reentry.
  • Four GRUS satellites built by Axelspace company, also from Japan, were designed for the Earth observation at a strict revisit rate.
  • The NAJM-1 satellite, built by LinaSpace in the United States for the King Abdulaziz City for Science and Technology, KACST, Saudi Arabia. It was described as an experimental and educational small satellite pathfinder mission for low-duty cycle imaging of the Earth's surface and communication from the low earth orbit.
  • DMSat-1 (a.k.a. SmallSat or AirWatch) was supplied by the Governing Council of the University of Toronto (as represented by the Institute for Aerospace Studies, Space Flight Laboratory, SFL, for the Mohammed Bin Rashid Space Center, MBRSC, in the United Arab Emirates to perform multi-spectral observations in the visible and near-infrared bands in order to detect and monitor aerosols in the upper atmosphere. The data could be used for monitoring of air contamination and climate change studies.
  • Three Adelis-Samson (-1, -2 and -3) 6U cubesats were developed at Technion technical university in Haifa, Israel, and were designed to demonstrate the capability of the multiple satellites to perform an autonomous formation flight and provide elocution positioning for a terrestrial transmitter. Two of the satellites were to be ejected from a QuadPack deployer provided by ISIS Space, ISL, from the Netherlands and the third Adelis-Samson was to share a ride in another QuadPack container with a Thai NAPA-2 satellite, which did not make it to the flight.
  • A pair of Kepler-6 and -7 satellites built by Kepler Communications Inc., Canada, were designed for the wide-band and high data rate communication in Ku-Band, as well as low-data rate narrow-band communications in S-band. The spacecraft was to provide data transfer services to locations, assets, and IoT systems distributed across the globe with the Global Data Service, GDS, and Everywhere IoT services.
  • NanoSatC-BR2 is a scientific, academic and technological satellite designed for monitoring of the Earth’s ionosphere and magnetic field. It was developed at the Southern Regional Space Research Center within the University of Santa Maria, Brazil.
  • The KMSL (Korea Microgravity Science Laboratory) satellite was intended for microgravity experiments prepared by the College of Engineering from Chosun University in Gwangju, South Korea.
  • Pumbaa (2U cubesat) and Timon (1U cubesat) satellites were developed at Astrodynamics and Control Laboratory of Yonsei University, Seoul, South Korea and intended for imaging solar corona, including its region that is 10 times wider than the Sun’s angular diameter. Intended to work in tandem, Timon carries a camera and Pumbaa is equipped with an occultation shade blocking the sunlight.
  • A quartet of Beesat satellites (-5, -6, -7 and -8) from the Technische Universität Berlin, Germany, were designed to test four different systems:
    • A UHF communications system;
    • An X-band experimental transmitter for the Global Navigation Satellite System, GNSS;
    • An optical sensor for situational positioning;
    • A laser range finder for precise orbit positioning.
  • The Hiber-3 satellite from the Netherlands was designed for testing “Internet-of-Things”, IOT, services.

NanoSatC-BR2, KMSL, Pumbaa, Timon and the BeeSat cluster share the ride to orbit inside QuadPack deployer No. 1.

  • The Unisat-7 platform was developed by GAUSS Srl, from Italy, as a carrier for the highly accurate deployment of small satellites in the CubeSat format. In addition, the spacecraft could function as a flexible in-orbit technology demonstrator and as an RF transmitter for radio-amateurs worldwide. It also carried a small experimental engine called Regulus. During its mission, Unisat carrier was expected to release six sub-satellites:
    • A Unicorn-1 2U cubesat, a.k.a. Wormsail, originating from Germany, was designed for testing high-precision deployment of cubesats;
    • An Argentinean DIY-1 was intended for testing satellite disposal, flight qualification of radio equipment and solar panels;
    • An Italian FEES payload had educational and research purposes;
    • Another Italian payload dubbed STECCO was also classified as educational and scientific and expected to test an attitude control method with the help of gravity gradient;
    • SMOG-1 from Hungary and
    • BCCSat-1 built in Thailand and carrying four cameras, were also identified as educational and research payloads.

A trio of of Russian cubesat payloads was packed into the so-called 4 by 3U + 6U deployer provided by the Russian company Aerospace Capital:

  • Several small Russian satellites were also onboard, including the first satellite from the High School of Economics, VShE. Known as NIU VShE-DZZ, the satellite was developed for remote sensing purposes in a joint effort between Moscow Institute of Electronics and Mathematics, MIEM, and Sputniks company. Representing the 3U CubeSat, it was equipped with an experimental camera with a resolution of around 50 meters and based on the stepped (Fresnel) lenses, developed by the Samara University, and with a high-speed X-range transmitter. MIEM students were responsible for qualification of the satellite’s control systems.
  • Another 3U CubeSat was developed by the Russian Sirius education center and VShE. The spacecraft was equipped with an improved DeCor-type instrument to monitor quick changes in the space radiation fluxes. Researchers from the Sirius education center and the Moscow University’s Scientific and Research Institute of Nuclear Physics were in charge of the project’s scientific component – handling the space radiation detector and mission’s mathematical algorithms.
  • An even larger OrbiKraft Zorky spacecraft, based on the 6U CubeSat with the size of 10 by 20 by 30 centimeters, was also developed at Sputniks. The eight-kilogram satellite was equipped with a high-resolution (from 6.6 to 15 meters per a pixel, according to various reports) telescope camera manufactured by the Lepton Research and Production Association, NPO Lepton. According to Sputniks, the resolution of the optical imager, reaching several meters per pixel, is unique for a spacecraft of that size. The project was supported by the Innovation Facilitation Fund, a.k.a. Bortnik Fund.

Aerospace Capital also supplied another 4 by 3U deployer for another group of cubesats, including:

  • The SIMBA satellite developed at the University of Rome, La Sapienza, was designed for monitoring of the wildlife behavior.
  • The GRBAlpha satellite, from the University of Košice, Slovak Republic, was intended to demonstrate the detector technology and electronics for the future Cubesats Applied for MEasuring and LOcalising Transients, CAMELOT, mission, which is a planned constellation of nano-satellites providing all-sky coverage with high sensitivity and localization accuracy following detections of gamma-ray transients. Several other universities participated in the project.
  • The UK-based Open Cosmos Ltd., provides end-to-end satellite missions, is the supplier of two payloads. The company has been responsible for the design, manufacturing, integration and mission management of the custom-built nano-satellites for Lacuna Space and Sateliot.
  • Lacuna Space (LacunaSat-2B, LS2-B) provides global connectivity for the Internet-of-Things devices.
  • Sateliot is the satellite telecommunications operator that plans to launch a constellation of nano-satellites to democratize the Internet of Things with 5G coverage. The company plans to deploy 16 satellites starting in 2022 and reaching 96 by 2025 at the investment of over 100 million Euros.
  • Challenge One satellite was another payload for the Internet of Things, IoT, service and includes an innovative communication technology developed at the TELNET company with the Tunisian expertise, even though the base platform was apparently provided by Sputniks in Russia. The project was expected to be the basis for the creation of a new space ecosystem for Tunisia and its region. The mission's launch date of March 20 coincided with the 65th anniversary of Tunisian independence.
  • KSU CubeSat for the College of Engineering, COE, at King Saud University, in Riyadh, Saudi Arabia, was designed for sending telemetry data and photos from the space to the ground station. The satellite was built by Sputniks LLC in Russia.

A few payloads previously registered for the flight apparently did not make it to the launch campaign and had to be replaced with dummies to preserve the geometry and the center of gravity of the stack during the flight. The missing payloads included the NAPA-2 satellite from the Royal Air Force of Thailand and the Vigoride spacecraft mockup from NPO Lavochkin.


A payload section with the CAS-500-1 spacecraft and secondary satellites is being prepared for encapsulation under its payload fairing on March 12, 2021.

Summary of payloads during the launch of CAS-500-1 satellite:

Spacecraft designation
KARI, South Korea
Remote sensing
ELSA-d Chaser
Astroscale Holdings Inc., Japan
Docking, space junk disposal
ELSA-d Target
Astroscale Holdings Inc., Japan
Docking, space junk disposal
GRUS (1)
Axelspace, Japan
Earth observation
GRUS (2)
Axelspace, Japan
Earth observation
GRUS (3)
Axelspace, Japan
Earth observation
GRUS (4)
Axelspace, Japan
Earth observation
KACST, Saudi Arabia
Earth observation
DMSAT-1 (SmallSat)
Muhammad Ben Rashid Space Center, UAE
Multi-spectral atmospheric observations
Technical institute, Israel
Technical institute, Israel
Haifa Technion, Israel
Kepler Communications Inc. Canada
Communications in S-band
Kepler Communications Inc. Canada
Communications in S-band
Santa-Maria University, Brazil
Ionosphere, magnetic field studies
Chosun University, Gwangju, South Korea
Microgravity studies
Yonsei University, Seoul, South Korea
Solar corona studies
Yonsei University, Seoul, South Korea
Solar corona studies
Berlin Technical University, Germany
Communications, navigation experiments
Berlin Technical University, Germany
Communications, navigation experiments
Berlin Technical University, Germany
Communications, navigation experiments
Berlin Technical University, Germany
Communications, navigation experiments
The Netherlands
Internet of Things, IoT
GAUSS Srl, Italy
Satellite deployer
Spacecraft separation experiment
Experimental orbital reentry
Gravitational stabilization experiment
Bangkok Christian College, Thailand
Higher School of Economics, Tikhonov MIEM NIU, Sputniks, Russia
Remote sensing
Sirius Center, NIU VShE, Russia
Space radiation
Sputniks, Russia
Remote sensing
University of Rome, La Sapienza, Italy
Wild life monitoring
Koshitsa University, Slovak Republic
Gamma-ray monitoring
Lacuna Space (LacunaSat-2B)
Open Cosmos, UK, Netherlands
Internet of Things, IoT
Sateliot (3BGSAT)
Open Cosmos
Internet of Things, IoT
Challenge One
Telnet, Tunisia
Internet of Things, IoT
King Saud University
Remote sensing


Preparations for flight


The first and second stages of the Soyuz rocket for the CAS-500-1 satellite during assembly at Site 31 in Baikonur on March 5, 2021.

On January 11, 2021, GK Launch Services announced that the Fregat upper stage, ELSA-d, DMSAT-1, UNISAT-7, three GRUS and a Fukui Prefectural Satellite arrived at the Baikonur Cosmodrome in preparation for launch on March 20.

The CAS-500-1 satellite was delivered to Baikonur on January 24, 2021. Autonomous electric tests of the spacecraft had been completed by February 20 and it was being prepared for fueling planned from February 21 to February 27.

By March 10, the CAS-500-1 satellite and the truss with the secondary payloads were integrated with their Fregat upper stage and ready for the installation of the payload fairing, which was completed on March 12.

On March 14, the payload section was integrated with the third stage of the Soyuz rocket and by March 15, the resulting upper composite was connected to the pre-assembled first and second stages, completing the integration of the launch vehicle. On March 16, the State Commission cleared the rocket for the rollout to the launch pad at Site 31. The rocket left the assembly building around 05:30 Moscow Time on March 17, 2021. After installation of the vehicle in vertical position, the first day on the pad was spent on autonomous tests of the payload, the rocket stages and ground equipment. At the end of the second day of on-pad preparations on March 19, Head of Roskosmos Rogozin announced the launch vehicle had passed the integrated tests with flying colors.


Soyuz-2-1a with CAS-500-1 satellite shortly after installation on the launch pad on March 17, 2021.

First launch attempt scrubbed

Key operations of the pre-launch operations were conducted during the night from March 19 to March 20. On the morning of March 20, the State Commission overseeing the preparations met and gave the green light to the fueling of the rocket's three booster stages and confirming the launch time. The loading of the kerosene aboard the first and second stages started at 05:03 Moscow Time. However, less than an hour from the planned liftoff on March 20, the launch attempt had been scrubbed due to technical reasons. The access gantry remained in place around the rocket at the time of its planned retraction normally conducted 30 minutes before liftoff. Several minutes after that milestone had not been met, the official live broadcast was concluded with a report about a technical problem requiring the delay.

Within an hour after the scrub, Roskosmos announced that the launch attempt would be repeated in 24 hours. Around the same time, the official RIA Novosti news agency quoted Roskosmos head as saying that a spike in the electric current prompted caution and required to postpone the launch. An industry source told that a power interruption from the ground network had caused the scrub. South Korea's Ministry of Science and ICT issued a statement implying that the problem had been detected during the final checks of the flight control system aboard the Fregat upper stage.

By the end of the day on March 20, Roskosmos announced that the meeting of the State Commission that had reviewed the discovered technical problem, made a decision to make the next launch attempt on the morning of March 22, 2021. The announcement also quoted the Director General of Roskosmos Dmitry Rogozin as saying that "in Baikonur, the State Commission made a decision to repeat the tests of the Control Setup of Launch Readiness, KNSG, for the Fregat upper stage on March 21. On the condition of the positive outcome of the KNSG mode, the launch is planned for Monday, March 22."

The decision was for the second fueling of the rocket was expected to be made by a State Commission meeting at 07:00 local time (05:00 Moscow Time) on March 22 to enable the liftoff at 09:07 Moscow Time, Glavkosmos said.

Soyuz lifts off on a second try


After a 48-hour delay, a Soyuz-2.1a/Fregat rocket lifted off from Pad No. 6 at Site 31 at Baikonur Cosmodrome on March 22, 2021, at 09:07:12.770 Moscow Time into the rainy sky.

The initial three-stage ascent of the Soyuz-2-1a rocket was largely routine with the liftoff under the simultaneous thrust of the four peripheral engines of the first stage and the central engine of the second stage. Somewhat unusually, the vehicle headed north and slightly west to align its ground track with a near-polar orbit inclined more than 97 degrees toward the Equator.

The four strap-on boosters of the first stage consumed their propellant first and dropped off 117.77 seconds after liftoff. In the meantime, the core booster continued firing until 4.7 minutes into the flight and separated at T+287.53 seconds, followed by the split and separation of three segments of the third stage skirt at 289.09 seconds and the halves of the payload fairing at 290.23 seconds. These three milestones were timed in close proximity from each other to ensure that all the debris fell in the designated drop zone along the mission's ground track.

Several days before planned launch, authorities in Sverdlovsk and Perm Regions of Russia issued a warning to local population for the rural Karpinsk District from March 20 to March 24, 2021. The projected impact site was bordered by a polygon formed by points located 20 kilometers north of the town of Kytlym, 10-12 kilometers northwest of Kakvinskie Pechi, 17 kilometers west of Sosnovka, 4-5 kilometers south of Denezhkin Kamen reserve, 2-3 kilometers north of the Konzhakovsky Gorge.

In the meantime, the third stage of the rocket ignited its engine moments before the separation of the second stage, firing for a few seconds through a lattice structure connecting the two boosters until the core stage dropped off. The third stage kept firing until T+525.75 seconds, cutting off just before it reached an orbital velocity in order to make sure it did not reach orbit and instead splashed down in the ocean. The third-stage booster separated from the Fregat fourth stage at T+528.7 seconds in flight.

Upper stage maneuvers

Shortly after entering its ballistic path, the Fregat upper stage was programmed to fire its main engine for the first time, reaching an initial parking orbit around the Earth. Shortly after the planned maneuver, Roskosmos confirmed that the first firing had gone as planned.

In the following two hours, the Fregat performed a series of maneuvers to enter three different sun-synchronous orbits. The CAS-500-1 satellite was to be released first into a 498.7-kilometer orbit with an inclination of 97.40 degrees toward the Equator at 10:10 Moscow Time or one hour and three minutes after liftoff from Baikonur and after two Fregat engine firings.

Around 10:50 Moscow Time, Roskosmos confirmed that CAS-500-1 had successfully separated from the Fregat. Glavkosmos also said that specialists from KARI had established contact with the satellite.

The Fregat then maneuvered to a 592-kilometer orbit with an inclination 97.73 degrees, where four GRUS satellites were released during a two-minute period from 11:35 to 11:37 Moscow Time. After another maneuver to enter the 550-kilometer orbit with an inclination 97.57 degrees toward the Equator, the remaining secondary payloads were separated from Fregat between 13:13 and 13:43 Moscow Time.

Roskosmos confirmed that all satellites had been successfully deployed.


Article by Anatoly Zak; Last update: March 22, 2021

Page editor: Alain Chabot

All rights reserved

insider content



CAS-500-1 during pre-launch processing. Click to enlarge. Credit: Roskosmos


CAS-500-1 satellite after integration with the payload adapter. Click to enlarge. Credit: GK Launch Services


The Unisat-7 platform during pre-launch processing. Click to enlarge. Credit: GK Launch Services


GRUS satellites and their processing team after the completion of the spacecraft integration with the payload adapter. Click to enlarge. Credit: GK Launch Services


An ELSA-d duo during pre-launch processing. Click to enlarge. Credit: Roskosmos


Artist rendering of ELSA-d satellites performing proximity operations in orbit. Click to enlarge.


Beesat team from Technical University of Berlin with their payloads. Click to enlarge. Credit: TU Berlin/F. Baumann


Installation of the OrbiKraft-Zorky into its launch container. Click to enlarge.


A pre-launch assembly of Tunisian Challenge One satellite. Credit: GK Launch Services


The DMSat-1 satellite is being prepared for integration with the Fregat upper stage in Vostochny. Credit: GK Launch Services


The Adelis-Samson satellite. Credit: GK Launch Services


A pair of Kepler satellites (6 and 7). Click to enlarge.


CAS-500-1 satellite (top right) is being prepared to be integration with the rest of the payloads. Click to enlarge. Credit: Roskosmos


A fully assembled payload section with the CAS-500-1 satellite. Click to enlarge. Credit: Roskosmos


The CAS-500-1 satellite and secondary payloads are encapsulated under a payload fairing. Click to enlarge. Credit: Roskosmos


Integration of the payload section with the third stage of the launch vehicle on March 14, 2021. Click to enlarge. Credit: Roskosmos


A Soyuz-2 rocket leaves the vehicle assembly building at Site 31 on the morning of March 17, 2021. Click to enlarge. Credit: Roskosmos


A Soyuz-2 is erected on the launch pad. Click to enlarge. Credit: Roskosmos


A Soyuz-2 shortly after installation on the launch pad at Site 31 on March 17, 2021. Click to enlarge. Credit: Roskosmos


Soyuz-2 lifts off on March 22, 2022. Click to enlarge. Credit: Roskosmos