Soyuz launches Gonets trio, military cargo
Russian military personnel at the Plesetsk Cosmodrome launched a fresh trio of Gonets-M satellites on a Soyuz-2-1b rocket in the early hours of December 3, 2020. It is the second Soyuz rocket mission to replenish Russia's low-orbital communications constellation in less than two months. However, unlike the previous launch on September 28, this time, there was no commercial hitchhiker payloads aboard the rocket. Instead, a small military satellite piggy-backed with the primary payload.
The 17th Gonets-M mission at a glance:
Preparations for launch
During the 17th launch of the Gonets-M satellites, the Soyuz-2-1b/Fregat rocket is expected to carry three Gonets-M satellites with production numbers 30, 31 and 32 for the 12-bird Gonets-D1M personal communications constellation developed at ISS Reshetnev based in Zheleznogorsk, Russia.
It will be the second Gonets-M mission launched on the Soyuz rocket, after the transition of the launches from the now-defunct Rockot booster.
In the middle of 2020, ISS Reshetnev announced that the second Soyuz launch with the Gonets trio was expected in November or December of the same year. In early September 2020, the company said that the three satellites for the mission had been removed from storage and had been undergoing electrical tests in preparation for shipment to the Plesetsk Cosmodrome at the end of the same month. By that time, the launch date was narrowed down to November 16, 2020. In early October, ISS Reshetnev reported that it had shipped the trio of satellites to Plesetsk with the plan to launch them at the end of November 2020. In early November, Reshetnev said that the satellites were in process of being integrated with their (Fregat) upper stage, followed by integrated electrical checks.
The Soyuz rocket for the second Gonets-M mission likely appeared in the footage released by Russian TV during a visit by Defense Minister Sergei Shoigu to Plesetsk on November 17, 2020.
On November 17, 2020, the Russian military announced that during a visit by the Minister of Defense Sergei Shoigu to the Plesetsk Cosmodrome (earlier that day), he had reviewed the preparation of the Soyuz-2 rocket for liftoff scheduled for November 24. At the time, the preparation of the rocket for the rollout to the launch pad was entering the final phase, the Ministry of Defense said, quoting Col. General Sergei Surovkin, the Commander of the Russian Air and Space Forces, VKS. Normally, the Soyuz rockets are rolled out to the launch pad two or three days before the planned liftoff.
On November 18, ISS Reshetnev confirmed that integrated electric checks of the satellites and their upper stage had entered the final phase and the installation of the payload fairing would take place in near future.
The launch was set for November 24, 2020, at 05:12:15 Moscow Time with the possibility for a second attempt available around 24 hours later. However, on November 21, just before the expected rollout of the rocket to the pad, electrical checks revealed a problem in one of communications channels of the Level Control System, SKU, monitoring fueling of the core stage and one of the strap-on boosters, an industry source said. The necessary replacements were expected to take around 10 days and required to postponing the launch until December 3. Once replacements had been completed, the rocket was rolled out to the launch pad on the morning of November 30, 2020. The liftoff was re-scheduled for 04:14:36 Moscow Time on December 3, 2020, (8:14 p.m. EST on December 2), as usual with an option for a 24-hour delay.
Soyuz launch profile with Gonets-M satellites
Under a 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 a near-orbital velocity, while flying over the Arctic Ocean.
Several minutes after the planned liftoff, the Russian Ministry of Defense confirmed that the mission carried a Gonets trio, but also disclosed a presence of a previously unidentified military satellite onboard, which was later described as an ERA-1 nano-service platform. In its press-release about the launch, Roskosmos said that the ERA-1 platform was intended for testing prospective micro-electronics and miniaturized instruments for attitude control and astro-navigation.
The Russian military also said that ground assets began tracking the vehicle at 04:16 Moscow Time. The separation of the Fregat upper stage from the third stage of the launch vehicle took place as planned at 04:24 Moscow Time, the Ministry of Defense said.
After the separation from the third stage, the Fregat fired its own main engine to enter an initial orbit, followed by a period of a passive flight before the final maneuvering to reach the destination orbit.
The Gonets-M satellites are normally delivered into a 1,400-kilometer orbit with an inclination 82.5 degrees toward the Equator. According to a posting on the Novosti Kosmonavtiki forum, the fourth spacecraft was scheduled to separate from the Fregat slightly more than six minutes after the release of the Gonets trio. After the completion of the first orbit beyond the range of Russian ground stations, the Fregat called home as the stage began its second revolution over Russia, the poster confirmed around 1.5 hours after liftoff. Soon thereafter, the successful separation of all four satellites was officially confirmed. The military payload was designated Kosmos-2548.
Following the release of its payloads, the Fregat upper stage is usually programmed to perform additional maneuvering to enter a disposal trajectory.
During the day on December 3, the Combined Space Operations Center, CSpOC, in the United States listed four objects associated with the launch, probably representing three Gonets-M satellites and the ERA-1 spacecraft:
In addition, in mid December 2020, or around two weeks after launch, the fifth small object (Object E) was detected in a 1,482 by 1,505-kilometer orbit with an inclination 82.501 degrees toward the Equator and an orbital period of 115.83 minutes.
Commenting on the completed launch, the head of the Gonets operator Pavel Cherenkov said that the deployment of the new satellites for the Gonets-D1M constellation also coincided with the introduction of four new regional stations for the system in 2020 which considerably improved the operation of the ground segment supporting the Gonets network. As a result, the Gonets-D1M constellation was ready to provide services to its users and had scale-up capabilities in the list of services and a number of users, Cherenkov said.
Gonets-M in orbit. Click to enlarge. Copyright © 2019 Anatoly Zak
A photo released in the middle of 2020 shows the processing of the Gonets-M satellites. Click to enlarge. Credit: ISS Reshetnev
Soyuz-2-1b with Gonets-M satellites is rolled out from the vehicle assembly building on November 30, 2020. Click to enlarge. Credit: Arianespace
Soyuz-2-1b is being fueled for launch in early hours of December 3, 2020. Click to enlarge. Credit: Arianespace
Soyuz-2-1b lifts off from Plesetsk on December 3 with a trio of Gonets-M satellites and ERA-1 test payload. Click to enlarge. Credit: Arianespace