ROSCOSMOS logo.
May 21, 2021
20 years ago, on May 21, 2001, the first launch of the Soyuz-FG launch vehicle took place. It was developed on the basis of the most massive Soyuz-U launch vehicle to support the launches of new Soyuz-TMA manned spacecraft and Progress M cargo spacecraft as part of the Russian International Space Station program.
The three-stage medium-class Soyuz-FG launch vehicle was part of the Soyuz series of launch vehicles developed on the basis of the R-7 launch vehicle with the addition of a third stage unit and operated since 1963. The launch vehicle underwent significant modernization in 1973, receiving the name "Soyuz-U", the modification of 1982 was called "Soyuz-U2". A further modification of the Soyuz-U launch vehicle is the Soyuz-FG launch vehicle (2001).
For the first time, the Soyuz-FG launch vehicle was launched on May 21, 2001. Then she launched the Progress M1-6 cargo ship into space. Later, these missiles were used to launch Progress, piloted by Soyuz, and for launches on commercial orders. For the first time, the Soyuz-FG rocket was used to launch a manned spacecraft on October 30, 2002. Then, with the help of it, the first Russian transport manned spacecraft of a new modification, Soyuz TMA-1, was launched to the International Space Station. Prior to that, Soyuz-U launch vehicles were used to send manned spacecraft to the ISS.
In the process of modernization, the blocks of stages I and II were modified: the RD-108 and RD-107 engines were replaced by the RD-107A and RD-108A propulsion engines with increased energy characteristics and an increased margin of stability of the working process in the chambers. This was achieved by improving the nozzle heads of the engines. To work together with the RD-107A and RD-108A engines, modernized steering units were used, in which the mass ratio of the fuel components was increased to increase the specific thrust impulse. Also, "Soyuz-FG" has proven itself excellently when launching satellites in commercial projects.
Structurally, the Soyuz-FG launch vehicle, like all missiles of the Soyuz family, is made according to the scheme of longitudinal-transverse division of rocket blocks. The rocket blocks forming the first and second stages are connected according to the "package" scheme: four side blocks are installed around the elongated central block. The third stage is connected in series with the central unit.
At the first stage of the flight, the engines of the four side and central blocks operate, at the second - after the separation of the side blocks - only the engine of the central block. In the tail compartment of each side unit, there is an autonomous four-chamber liquid-propellant rocket engine of a single start RD-107A, equipped with two steering nozzles.
The central block of the second stage uses a four-chamber RD-108A engine with four steering nozzles. The launch of the liquid-propellant engine of the central and lateral blocks is carried out on the ground, which makes it possible to control the operation of the engines in the transient mode and, in the event of malfunctions during the launch, cancel the launch of the rocket. This significantly increases the safety of spacecraft launches to the International Space Station.
At the third stage, the RD-0110 propulsion system is used, consisting of a four-chamber single-turn engine and four rotary steering nozzles (used to control the flight along three axes). After the engine of the third stage is switched off and the space warhead is separated, the third stage performs a withdrawal maneuver.
As part of the Soyuz-FG rocket, head fairings of diameters were used: 2.7 meters; 3.0 meters; 3.3 meters; 3.715 meters. The upper stage is not used for launches of manned and cargo spacecraft.
The Soyuz-FG launch vehicle is considered one of the most reliable in the world, with a confirmed operational reliability indicator of 0.9855. From 2011 to 2019, the Soyuz-FG launch vehicle was the only vehicle for delivering crews to the International Space Station. Soyuz-FG has been in operation for 18 years. The last 70th launch took place on September 25, 2019 from the Baikonur cosmodrome.
Since 2020, manned spacecraft have been launched on the new Soyuz-2.1a missiles. This launch vehicle is distinguished not only by the fact that instead of analog equipment, modern digital systems are installed on it, but also by the fact that all rocket equipment is completely manufactured in Russia.
ROSCOSMOS Press Release: https://www.roscosmos.ru/31113/
RCC Progress: https://www.roscosmos.ru/tag/rkc-progress/
Images, Text, Credits: ROSCOSMOS/Orbiter.ch Aerospace/Roland Berga.
Best regards, Orbiter.ch
