Russia launches multi-satellite rideshare mission on commercial Soyuz flight

by William Graham & Danny Lentz

Russia’s federal space agency Roscosmos launched its first dedicated commercial launch through its GK Launch Services subsidiary, using a Soyuz 2.1a/Fregat vehicle to deliver a cluster of satellites to orbit, including South Korea’s CAS500-1. 

Soyuz – sporting a new blue and white livery – lifted off from Site 31/6 at the Baikonur Cosmodrome, Kazakhstan on Monday, 22 March at 06:07 UTC, which was 12:07 local time and 02:07 EDT. This followed a scrub about 30 minutes before launch on Saturday’s attempt.

GK Launch Services is a joint venture between Glavkosmos – the commercial arm Roscosmos – and launch services company ISC Kosmotras, which contracted commercial flights of the Dnepr rocket prior to its retirement. 

While GK has contracted secondary payloads on several past launches of government satellites, this mission marked the first time that it was responsible for a dedicated launch.

In all, this flight launched with 38 satellites in a variety of sizes, from 500 kg microsatellites to .25U CubeSats and 1P PocketQubes.

Microsatellites:

The primary passenger, the 500 kg CAS500-1 remote sensing satellite for South Korea, was built by Korea Aerospace Research Institute (KARI) and industry partners. This is the first in a series of satellites based on a new bus design for the Korean satellite industry.

The electro-optical payload can produce panchromatic images with a resolution of around 0.5 meters and multispectral images with a resolution of around 2 m.

The co-passengers on the flight included multiple microsatellites for a pair of Japanese companies. Axelspace has four GRUS satellites, each massing about 100 kg, for Earth imaging at a resolution of 2.5 m. One of those satellites is sponsored by the Fukui prefectural government.

Astroscale has the ELSA-d (End-of-Life Service by Astroscale demonstrator) mission which comprises a pair of microsatellites that will be launched as one unit. Once on orbit the smaller target vehicle will be released and the duo will perform a series of demonstrations for proximity operations and magnetic capture between the two satellites. After the demonstrations are over, the pair will passively deorbit over a period of about 7 years.

The 32 kg Unisat-7 microsatellite from Italy’s GAUSS will perform technical demonstrations and also deploy several CubeSats and PocketQubes for their clients. The payloads to be deployed include: the 1U sized BBCSAT-1 multi-spectral imaging satellite built by high school students in Thailand; the .3U sized FEES from Italy; the 1P sized DIY-1 from Argentinian startup Diysatellite; the 1P sized SMOG-1 from Hungary; and the 6P sized STECCO from Italy to test attitude control. 

Other tasks for Unisat-7 include testing the REGULUS plasma thruster for T4i and hosting an amateur radio payload.

Saudi Arabia’s NAJM 1 satellite is an experimental pathfinder for Earth imaging and communications while the United Arab Emirates’ 15 kg DMSat-1, built by UTIAS Space Flight Laboratory in Toronto, will perform multispectral imaging.

There is a mass simulator for a Momentus Vigoride vehicle which was previously scheduled for this flight, but is now slated to fly on the Transporter 2 on a Falcon 9 rocket launch in June.

Nanosatellites:

The Netherlands-based ISILaunch has four quadpack CubeSat deployers on the flight containing 14 satellites for seven customers.

The integrated payload stack awaits fairing encapsulation. CAS500-1, the largest satellite on this mission, is seen bolted to the top of the stack, which is rotated horizontal. (Credit: Roscosmos)

Canadian company Kepler has a pair of 6U CubeSats for their IoT and communications constellation. Dutch company Hiber also has a 3U satellite for their IoT constellation.

The Adelis-SAMSON (Space Autonomous Mission for Swarming and geOlocating Satellites) mission from Technion-Israel Institute of Technology consists of three 6U satellites that will fly in formation to detect and triangulate the position of RF transmitters on Earth.

Yonsei University in South Korea has their pair of Canyval-C CubeSats, the 1U TIMON and 2U PUMBAA, named after characters from The Lion King. These satellites will attempt to fly in formation with PUMBAA deploying a shade that will occult the sun for TIMON, which will image the solar corona.

BeeSat-5/6/7/8 from Technical University of Berlin is a set of .25U CubeSats that will test satellite navigation receivers and intersatellite communications in the UHF band.

KMSL (Korea Microgravity Science Laboratory) is a 3U CubeSat from Korea’s Chosun University with experiments on combustion and biological sciences.

NANOSATC-BR2 is a 2U cubesat for Brazil that will study Earth’s ionosphere and magnetic field.

Another pair of quadpack CubeSat deployers from Russia’s Aerospace Capital is on board. These carry nine more CubeSats: ChallengeOne, the first Tunisian built satellite, a 1U CubeSat for IoT; the 1U WildTrackCube-SIMBA from Sapienza University of Rome for tracking wildlife movements, which won a contest for a free launch; the 1U sized KSU cubesat from King Saud University in Saudi Arabia; 3U IoT CubeSats for UK based Lacuna (LacunaSat2-B) and Spain’s Sateliot (3B5GSAT), with mission management from Open Cosmos; the 1U GRBAlpha from Slovakia’s Technical University of Kosice; a pair of 3U spacecraft, CubeSX-HSE and CubeSX-Sirius-HSE, from NIU VShE in Russia; and the 6U ORBICRAFT-ZORKIY from Russia’s Sputnix.

Soyuz

The trip to orbit for the rideshare mission’s passengers was aboard Russia’s workhorse Soyuz 2.1a carrier rocket using a Fregat upper stage. First flown in 2004, this is one of three versions of the Soyuz-2 rocket which have replaced earlier iterations of the Soyuz design in Russia’s launch fleet

Soyuz is manufactured by the RKTs Progress joint-stock company headquartered in Samara and dates back to the 1960s, with the original design an upgraded version of the earlier Voskhod rocket – itself derived from Sergei Korolev’s R-7 missile. 

R-7 first flew in 1957, becoming the world’s first intercontinental ballistic missile (ICBM). Later that year, it launched the first artificial satellite, Sputnik, into orbit. Although its time in service was short, as it was quickly superseded by other designs with storable liquid and later solid propellants which could remain on alert for much longer periods, its derivatives – including Soyuz, Voskhod, Vostok and Molniya – have served as the backbone of the Soviet and later Russian space programs ever since. 

First flown in 1966, Soyuz was initially used in support of the human spaceflight program of the same name, launching initial test flights and – beginning the following year – crewed missions. Over the next few years, several modified versions of Soyuz were built to launch a handful of reconnaissance satellites and test flights related to the Soviet lunar program.

But the most significant development was the Soyuz-U in 1973. This replaced all previous Soyuz variants, as well as the earlier Voskhod which was still being used for most military launches. The most-flown orbital carrier rocket of all time, the Soyuz-U remained in service until 2017, making over 750 launches.

In November 2004, the first Soyuz-2 rocket, a 2.1a, made its first flight. A suborbital test carrying an obsolete reconnaissance satellite to simulate a payload, this tested new enhancements aimed at bringing the Soyuz design into the 21st century. Changes included upgraded engines and a digital flight control system, with the rocket gaining the ability to roll onto a desired launch trajectory for the first time.

This successful test paved the way for a first orbital launch in October 2006 with the European METOP-A weather satellite.

Soyuz-2 can be used in conjunction with two different upper stages – Fregat and Volga – to make a four-stage vehicle. These configurations allow it to deliver payloads to higher orbits or to perform more complex missions – such as multiple satellite deployments – than the three-stage Soyuz can achieve. 

Fregat, used on this mission, is the most commonly used upper stage while Volga is used for smaller payloads, often in conjunction with the Soyuz 2.1v.

Soyuz launches take place from four sites worldwide: the Baikonur Cosmodrome in Kazakhstan, the Plesetsk and Vostochny Cosmodromes in Russia, and the Centre Spatial Guyanais in Kourou, French Guiana. Slightly different versions of the rocket are used depending on the launch site – while the rockets that fly from Plesetsk and Baikonur are the same, rockets built to fly from Vostochny and Kourou require different on-board computer and telemetry systems, while those destined for Kourou – the Soyuz-ST subclass – also need to be adapted for the tropical conditions at that launch site.

The launch was from Baikonur, using the launch pad at Site 31/6. This is one of two Soyuz launch pads at Baikonur, the other being the historic Site 1/5 from which both Sputnik 1 and Yuri Gagarin’s Vostok 1 missions were launched. Both launch pads date to the 1950s, having been built to support testing of the R-7.

Soyuz on Site 31/6 at Baikonur. (Credit: Roscosmos)

Site 1/5 is yet to undergo the modernization required to launch Soyuz-2 rockets and has therefore been inactive since the Soyuz-FG – the last previous-generation version of the rocket – was retired in 2019. This leaves Site 31/6 as the only operational Soyuz pad at Baikonur.

While the launch was the first dedicated commercial flight for GK Launch Services, it is far from the first time Soyuz has performed a commercial mission. European Arianespace has been conducting launches with Soyuz on behalf of commercial organizations and the European Space Agency since the start of the 2000s. 

Initially, these were made from Baikonur through the company’s Starsem subsidiary before the dedicated commercial launch pad in Kourou came online in 2011. Starsem continues to conduct commercial Soyuz launches from Baikonur and Vostochny.

To celebrate GK’s first commercial mission, Soyuz sported a new white and blue livery, inspired by the color scheme of a prototype Vostok rocket that is preserved in Moscow. Glavkosmos expects to use the same livery on future commercial missions that it contracts.

As with all Soyuz launches, the rocket that flew this mission was integrated horizontally in the assembly building, or MIK, away from the launch pad. This includes the payload, since the older launch facilities at Baikonur and Plesetsk cannot support vertical payload integration at the pad. 

The storable-propellant Fregat was fuelled prior to integration with the rocket and is encapsulated in the fairing along with the payload for launch. 

With assembly completed, Soyuz was taken by rail to the launch pad on Wednesday, 17 March and raised vertical.

Launch

About 16 seconds before the launch countdown reaches zero, the engines on the four boosters and the Blok-A core stage of Soyuz began their two-step ignition process. The four boosters, also called the first stage, are clustered around the Blok-A core (also called the second stage) and use one RD-107A engine each. 

The Blok-A core stage has a single RD-108A – a modified RD-107A engine, which incorporates additional vernier nozzles to help control the rocket’s attitude. The booster and Blok-A stages all use RG-1 propellant: rocket grade kerosene, which is oxidized by liquid oxygen.

When they ignite, the engines are fired at a low thrust level to allow a good combustion to begin via large chemical matches that are inserted into the engine nozzles at the launch pad. A stable combustion in all combustion chambers is confirmed when sensor wires in the chambers are severed — telling the Soyuz’s onboard computers that the engines are ready to be brought to full thrust for liftoff.

That final command to full thrust occurred at T-4 seconds. With all engines up to full power, the launch pad arms swing open and Soyuz lifted off to begin the climb into orbit after rolling onto the correct orientation.

The first major event after liftoff was booster separation. The boosters fired the first 118 seconds of flight before exhausting their propellant. The four boosters detached from the Blok-A stage and vent residual oxygen to push themselves clear. Seen from the ground, this makes a distinctive pattern in the sky known as the Korolev Cross after the Soyuz rocket’s original Chief Designer.

The business end. Soyuz 2.1a’s four RD-107A and single RD-108A engines. Workers are preparing to insert the engine ignition “matches” – a critical pre-launch step for Soyuz. (Credit: Roscosmos)

 The Blok-A stage continued to burn its RD-108A engine for around another 170 seconds. At that point, the Blok-I stage above it ignited its engine while the Blok-A stage is still firing underneath in a “hot staging” technique which ensures the Blok-I stage propellant remains settled in its tanks. 

Exhaust gasses from the Blok-I stage escape through the lattice interstage. The Blok-I stage is powered by a single RD-0110 engine. This burned for about four minutes. 

A few seconds after ignition, the protective skirt at the aft end of the stage separated into three pieces and fell away from the vehicle.

At the end of the Blok-I stage burn, Soyuz was close to orbit – with Fregat performing the final insertion before making a series of burns to deploy its payloads into their designated target orbits. Powered by an S5.98M engine, Fregat is capable of making up to twenty separate engine burns in the course of a mission. It burns hypergolic propellant: unsymmetrical dimethylhydrazine oxidized by dinitrogen tetroxide.

The launch was the fourth of 2021 for Russia, following a trio of Soyuz launches last month. The rocket will be in action again as early as Thursday, 25 March with another commercial mission, this time conducted by Starsem out of the Vostochny Cosmodrome in Eastern Russia that is due to deploy 36 OneWeb communications satellites. 

The next launch from Baikonur will come on 9 April, when a Soyuz 2.1a will launch from the same pad as this mission with the crewed Soyuz MS-18 mission bound for the International Space Station.

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