Soyuz delivers its first Gonets-M satellites
Russian military personnel at Plesetsk Cosmodrome successfully launched a Soyuz-2-1b rocket on September 28, 2020, at 14:20 Moscow Time. The primary payload of the mission was a trio of Gonets-M communications satellites for Russia's low-orbital communications network, previously replenished by the discontinued Rockot booster. Along for the ride on the Soyuz was a cluster of 19 small satellites from an international group of customers. The Fregat upper stage deployed three Gonets satellites in their operational high-inclination orbit, followed by the release of secondary payloads in the Sun-synchronous orbit.
The 16th Gonets-M mission at a glance:
New passengers aboard Soyuz
During the 16th launch of the Gonets-M satellites, the Soyuz-2-1b/Fregat rocket was expected to carry three satellites with production numbers 27, 28 and 29 for the 12-bird Gonets-D1M personal communications constellation developed at ISS Reshetnev based in Zheleznogorsk, Russia.
In the course of its orbital deployment in the previous two decades, the Gonets project had to shift its launches from Tsyklon-3 to Kosmos-3M and to Rockot vehicles, as each previous rocket family was consecutively retired. The conversion of the UR-100UTTKh ballistic missiles into the Rockot launcher had to stop primarily due to lack of flight control systems supplied from Ukraine. As a result, Roskosmos State Corporation had to switch Gonets missions to the medium-class Soyuz-2-1b rocket. As of 2020, three Soyuz vehicles were ordered for the Gonets-M project, with two launches planned from Plesetsk and one from the Vostochny spaceport, which was planned to be outfitted with the necessary facilities to handle Gonets spacecraft, previously processed exclusively in Plesetsk.
The Soyuz rocket, which is around three times heavier than Gonets' previous delivery systems, was clearly oversized for carrying the trio of 280-kilogram Gonets satellites, but, Roskosmos apparently did not have either additional Gonets satellites or other comparable spacecraft to share the ride on the same rocket to a near-polar orbit, at least during the first such mission.
To at least partially fill the unused capacity of the Soyuz, the Glavkosmos subsidiary of Roskosmos offered commercial customers to piggyback on Gonets missions. For the first launch, the Berlin-based Exolaunch provider arranged a ride for 15 small payloads from seven international customers. Additionally, four small Russian satellites were also booked for the same mission.
On August 17, 2020, Exolaunch announced that it had struck agreements to prepare three micro-satellites weighing under 100 kilograms and 12 even smaller spacecraft in the so-called cubesat class for customers from Europe, Canada, USA and UAE. The company collectively nicknamed its payload "Wanderlust" or "desire to travel" to stress the fact that the launch campaign was taking place under the severe travel restrictions of the coronavirus pandemic. According to Exolaunch, the satellites were designed to deliver remote sensing, the Automatic Identification System, AIS, data for sea traffic, the Automatic Dependent Surveillance-broadcasts, ADS-b, for air traffic and the Internet of Things, IoT, as well as data for startups and the international scientific community.
A day after the ExoLaunch press release, Toronto-based Kepler Communications announced it would launch a pair of its 6U XL satellites carrying Ku-band communications system for the company's Global Data Service and for technology demonstration on the Soyuz rocket.
Next, the US-based Spire Global company said that it had booked a ride inside ExoLaunch's 12U EXOpod container for a quartet of its Lemur nano-satellites to add to its 100-plus constellation.
The launch of another quartet comprised of 3U cubesats named NetSat was ordered by Germany-based Würzburg Center for Telematics. According to the center, the NetSat would demonstrate the self-organization of several satellites in three-dimensional space to jointly optimize the configuration for given tasks. The satellites could be precursors of future sensor networks in space, including systems for three-dimensional imaging of the Earth's surface and computer tomography methods for looking inside clouds, the center said. NetSats were loaded into the 12U EXOpod launch containers in Berlin and only then transported to Plesetsk for installation on the Fregat stage.
In the meantime, Khalifa University in United Arab Emirates booked the launch of the 3U cubesat called MeznSat which was configured for monitoring greenhouse gases using short-wave infrared spectrometry.
The prime developer of the Gonets satellites ISS Reshetnev also built a new adapter designed to hold the Gonets trio on top of the structure, while launch containers for secondary payloads would be strapped to its sides. The entire contraption would then be mounted on the Fregat upper stage.
For the integration of the piggyback satellites with the adapter, the ExoLaunch provided the CarboNix shock-free micro-satellite separation system and EXOpod launch containers, which were previously used on earlier Soyuz/Fregat missions.
Only fragmentary information was available on the secondary Russian payloads of the mission. It is known that a 6U cubesat named Norbi was developed at Novosibirsk State University, NGU. A pair of Yarilo satellites, named after pagan god of Sun in the Kievan Rus, was developed at the Bauman Technical University, BMSTU, the chief provider of specialists for the Soviet and Russian rocket industry. Fittingly, these nano-class satellites were designed for uninterrupted observations of the Sun from orbital positions separated by at least 140 degrees from each other, which would guarantee that at least one of them would be on the sun-lit part of the orbit at any given time.
The necessary distance between the pair was expected to be achieved with the help of a two-blade solar sail deployed from a special module aboard the spacecraft. If successful, it would be the first Russian spacecraft propelled by a solar sail.
As their primary payload, the Yarilo satellites carried a foton detector, which was developed at the Lebedev FIAN institute in Moscow and was designed to register X-ray radiation from the Sun within range from 0.5 to 15 Kiloelectronvolts.
Summary of secondary payloads during the 16 Gonets-M mission:
Preparations for launch
As of June 2020, the launch of the 16th Gonets cluster was expected on September 20 and around the same time, ISS Reshetnev, which developed the Gonets-M system, reported that its specialists began preparation of three mothballed satellites for their shipment to Plesetsk. By the middle of June 2020, the company confirmed that the three satellites and their adapter had been delivered to the launch site. The satellites were expected to be assembled into a single cluster before their integration with the launch vehicle, ISS Reshetnev said. At the time, the launch was preliminary scheduled for September 24. However by the end of August, the mission was postponed until September 28, 2020.
On September 2, ExoLaunch announced that it had started its launch campaign in Plesetsk and around the same time, ISS Reshetnev reported that the autonomous tests of the three Gonets-M satellites had been completed and they had been installed on their adapter.
A relatively rare commercial mission originating from the Russian military launch site required a formal order of the Russian Prime Minister Mikhail Mishustin issued on September 10, 2020, which officially authorized the use of assets and facilities of the defense ministry for processing and launching foreign payloads.
Soyuz launch profile with Gonets-M satellites
The liftoff of the Soyuz-2-1b rocket took place as scheduled on September 28, 2020, at 14:20 Moscow Time (7:20 a.m. EDT).
According to the Russian Ministry of Defense, all launch operations went as planned and the assets of the Titov Chief Test Space Center began tracking the vehicle two minutes after liftoff. The separation between the third stage of the launch vehicle and the Fregat upper stage also took place as planned at 14:30 Moscow Time, according to the Ministry of Defense.
Under the standard launch profile of the Soyuz/Fregat vehicle, the first, second and third stages of the rocket accelerated the fourth Fregat stage and its payload to near-orbital velocity, while flying over the Arctic Ocean.
The Fregat then fired its own main engine to enter an initial orbit, followed by a period of passive flight and additional maneuvers to reach its destination orbits.
The vehicle left the communications range of Russian ground stations during the first Fregat firing and was not expected to contact mission control until its second orbit around the Earth.
The Gonets satellites are usually delivered into a 1,400-kilometer orbit with an inclination 82.5 degrees toward the Equator.
Following the release of the primary payload, the Fregat upper stage was expected to maneuver twice to enter a transfer orbit and the target orbit for the deployment of nearly 20 small payloads.
According to ExoLaunch, its customers' satellites were to be deployed into a range of sun-synchronous orbits with an altitude of 575 kilometers. It was the first mission of the Soyuz/Fregat vehicle involving a two-hour transition from orbit with an inclination 82.5 degrees to a Syn-synchronous orbit with an inclination of 97.67 degrees. The stage also reduced altitude by 925 kilometers. According to one poster on the Novosti Kosmonavtiki forum, such maneuver was early proposed by ballistic experts at Plesetsk for the Tsyklon-3 vehicle but was not implemented until this mission.
Another poster on the same forum wrote that the separation of the Yarilo-1 satellite had been scheduled for 17:57:12 Moscow Time, Yarilo-2 at 17:58:52 Moscow Time, followed by Dekart's release at 18:00:32 and by Norbi at 18:03:52 Moscow Time.
Around 18:20 Moscow Time on September 28, 2020, the Fregat was expected to perform its final maneuver to deorbit.
Several days before the planned launch, the Russian government issued notifications to sea and air traffic about closed areas in the Pacific Ocean, apparently to be used for the splashdown of the third stage at the end of its suborbital trajectory and for the controlled reentry from orbit of the Fregat upper stage after the conclusion of its satellite deployment operations.
A post-launch statement from the Russian Ministry of Defense said that the mission had successfully delivered the spacecraft into their planned orbit and Exolaunch also announced that prelliminary reports confirmed that all its manifested payloads had been deployed successfully.
According to the data from the US Space Command, USSPACECOM, the newly launched Gonets-M satellites were found on a 1,484 by 1,504-kilometer orbit with an inclination 82.5 degrees toward the Equator, typical for the spacecraft in the series.
On September 29, 2020, the MeznSat satellite was reported in contact with its ground control in the United Arab Emirates.
The official logo of the first Soyuz launch with Gonets satellites released a day after the successful launch on September 28, 2020. Credit: Roskosmos
Gonets-M in orbit. Click to enlarge. Copyright © 2019 Anatoly Zak
A pair of 6U XL satellites was carried on a Soyuz along with the 16th Gonets-M trio.
Commercial payloads are being processed for launch in Plesetsk circa September 2020. Click to enlarge. Credit: Exolaunch
Cubesat-class satellites are being prepared for launch in Plesetsk circa September 2020. Click to enlarge. Credit: Exolaunch
CarboNIX adapter for the release of micro-satellites was built by ExoLaunch. Click to enlarge. Credit: Exolaunch
Soyuz rocket arrives at launch pad for the 16th Conets mission on Sept. 26, 2020. Click to enlarge. Credit: Exolaunch