Soyuz 2-1A launches second Bars-M satellite
Russia launched its Soyuz 2-1A rocket on Thursday, successfully deploying a second Bars-M reconnaissance satellite. The launch from Site 43/4 at the Plesetsk Cosmodrome, located in the north of the country, occurred at 12:42 Moscow Time (09:42 UTC).
Soyuz 2-1A Launch:
Bars-M No.2 is the second of a new series of area reconnaissance satellites, designed to produce wider-angle images of the Earth than Russia’s other reconnaissance satellites such as Persona. Its images, which have a lower resolution than its counterparts, can be used for cartography and analysis of wider areas.
The Bars-M series of satellites replace the Yantar-1KFT film-return satellites operated by Russia, and previously the Soviet Union, between 1981 and 2005.
Also known as Kometa and Siluet, the 1KFT was able to remain in orbit for 45 days at a time before separating its film capsule for return to Earth. By contrast, Bars-M is designed to remain in operation for at least five years – downlinking images electronically rather than storing them on film for a later return to Earth.
The Bars-M spacecraft was developed by TsSKB Progress, with its Karat camera produced by the Leningrad Optical-Mechanical Association (LOMA).
With a mass of around four tonnes (4 Imperial or 3.6 US tons), the Soyuz-2-1a carrier rockets are used and operated in sun-synchronous orbits.
The spacecraft introduce a new bus and a propulsion system, designated SVIT, instead of the Yantar-derived buses and propulsion systems used by most of Russia’s imaging satellites.
Launches of Bars-M’s predecessor, the Kometa, ended in September 2005 with the launch of the twenty-first satellite, Kosmos 2415.
All deployed by Soyuz-U rockets flying from Baikonur, the Kometa spacecraft made use of a spacecraft bus developed by the TsSKB design bureau for its Yantar-2K spacecraft integrated with the return capsule from the Zenit series of reconnaissance satellites.
The Zenit capsule was itself derived from the Vostok spacecraft which carried the first cosmonauts into orbit in the early 1960s. Each capsule could be refurbished after landing and re-flown on up to three separate missions.
Thursday’s launch made use of Russia’s Soyuz-2-1a carrier rocket. A three-stage vehicle under Russian nomenclature, consisting of a set of four boosters – termed the first stage – clustered around two core stages, the Soyuz-2 was introduced in 2006 following a test flight two years earlier.
Intended as a replacement for earlier rockets including the Soyuz-U and Molniya-M, the Soyuz-2 was initially developed with two configurations.
The Soyuz-2-1a features modernised guidance systems and redeveloped engines on the first and second stages. The more powerful Soyuz-2-1b also incorporates a re-engined third stage with a new RD-0124 engine replacing the earlier RD-0110.
Introduced in 1966, the Soyuz was initially as a dedicated carrier rocket for the Soviet manned programme and its Soyuz spacecraft.
A close derivative of the earlier Voskhod rocket, the Soyuz traces its lineage back to the R-7 missile from which the Sputnik, Vostok and Molniya series of rockets were also derived.
In the early 1970s the original Soyuz and the Voskhod were replaced by a new rocket, the Soyuz-U, which still remains in service.
Two close derivatives of the Soyuz-U have also been flown; the Soyuz-U2 – operated in the 1980s and 1990s – used synthetic propellant to increase its performance, while the Soyuz-FG is an enhanced variant used primarily to launch the manned Soyuz-TMA spacecraft.
The Soyuz-2-1a and b are currently in the process of replacing the Soyuz-U and will eventually also replace the Soyuz-FG.
The Soyuz-2-1a and 2-1b have since been joined by a third configuration, the Soyuz-2-1v, which is a less powerful rocket intended to replace some of the smaller vehicles in Russia’s launch fleet.
Omitting the first stage, or boosters, present in the Soyuz-2-1b configuration, it also uses an NK-33 engine on the lower stage of the core in place of the RD-108A present in the other variants.
Commercial Soyuz-2 launches are conducted by Arianespace from its launch site at Kourou, French Guiana, with the Soyuz-2-1a and 2-1b designated Soyuz-STA and Soyuz-STB respectively.
These vehicles feature minor modifications to adapt them for launch from Kourou, most significantly the introduction of a flight termination, or self-destruct, system to allow range safety to destroy the rockets if they should go off course.
The launch took place from Site 43/4 at the Plesetsk Cosmodrome in Northern Russia.
The four boosters which make up the first stage of the Soyuz-2-1a vehicle are designated Blok-B, V, G and D. Each powered by an RD-107A engine, they ignite along with the core, or Blok-A, stage’s RD-108A engine approximately seventeen seconds before launch.
Slowly building thrust ahead of liftoff, once the vehicle reaches its full performance the four launch pad arms which hold it in place will swing back, allowing it to rise from the pad.
First stage flight lasted a little under two minutes, with the four boosters separating to form a pattern which has become known as the Korolev Cross after Sergei Korolev, the chief designer of the OKB-1 design bureau which developed the R-7 missile along with many early Soviet missiles and spacecraft.
Following first stage separation the second stage continued to burn for around two minutes and fifty seconds, during which time the payload fairing separated from around the spacecraft.
At the end of the second stage burn the spent stage will have separated and the third stage, or Blok-I, will have ignited its RD-0110 engine for approximately-four-minutes. All three stages burn T-1 propellant, oxidised by liquid oxygen. T-1 is a refined form petroleum similar to the RP-1 kerosene or paraffin propellant used in American rockets.
The Soyuz-2 flew without an upper stage, so following third stage burnout the spacecraft will have separated to begin its mission.
It is believed that the target orbit for the mission is an elliptical transfer trajectory which will allow the spacecraft to manoeuvre itself into a sun-synchronous orbit.
The third satellite in this range expected to fly around 2018.
(Images via Roscosmos, TsSKB-Progress and L2’s Soyuz 2-1V documentation).