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Soyuz Launches GLONASS Navigation Satellite from Plesetsk

Russia has added another satellite to its current satellite navigation upper stage for the GLONASS launch. The Fregat, when used in
network with the successful launch of a Soyuz-2.1b/Fregat rocket. conjunction with Soyuz, allows satellites to be placed into higher
Liftoff occurred at 5:52 AM Moscow Time (02:52 UTC) on Oct. or more complex orbits than could be achieved using just the
10 from the Plesetsk Cosmodrome in the northwestern part of core vehicle. In the case of GLONASS missions, it allows for direct
Russia carrying GLONASS-K1 No. 17. The GLONASS constellation insertion into medium Earth orbit. The Soyuz-2.1b is a modernized
of satellites is very similar to the US Global Positioning System version of the Soyuz family of rockets, which trace their history
(GPS) and European Galileo satellites. GLONASS uses satellites back to Sergei Korolev’s R-7, the world’s first intercontinental
in medium Earth orbit broadcasting highly accurate timing signals ballistic missile. The R-7, which first flew in 1957, was also used to
which receivers can use to triangulate their locations. GLONASS launch the world’s first satellite, Sputnik, and formed the basis of
satellites broadcast four navigation signals in the L-band: the rockets that carried Yuri Gagarin’s Vostok 1 mission into orbit.
unrestricted L1 and L2 signals for civilian use, and equivalent It also deployed the Soviet Union’s earliest probes to the Moon
restricted signals for the Russian military. The GLONASS satellites and other planets. The Soyuz-2 series was engineered to improve
are positioned in three different planes 120 degrees apart from performance and reliability. Digital flight control systems replace
each other with eight satellites in each plane. This particular the analog equipment used on earlier versions of the Soyuz, while
satellite will function in medium Earth orbit at an altitude of 19,100 the first and second-stage engines have also been upgraded. In
km (11,900 mi) and a 64.8° inclination. This plane allows for addition, the Soyuz-2.1b uses an RD-0124, a more powerful third-
coverage to higher latitudes, which can be difficult to reach with stage engine. Soyuz launched from Site 43/4 at the Plesetsk
traditional GPS networks operating at a 55° inclination. The first Cosmodrome in Northwest Russia. Plesetsk is one of four Soyuz
satellite in the GLONASS network was launched in 1982, eventually launch sites worldwide – alongside the Vostochny Cosmodrome
reaching full capacity in 1996. Previous satellites in the GLONASS in Eastern Russia, the Baikonur Cosmodrome in Kazakhstan, and
constellation had short lifetimes, resulting in 140 different satellite the Centre Spatial Guyanais in Kourou, French Guiana, although
launches as old ones failed and needed replacing. In 2001, the launches from the latter have been placed on hold during the
switch was made to the Uragan-M model, which offers a fivefold ongoing Russian conflict with Ukraine. The ignition sequence for
increase in accuracy as well as an improved on-orbit lifespan. The the Soyuz rocket began 16 seconds before liftoff. That includes
current generation of GLONASS-K1 satellites, including No. 17, is the first stage, which consists of four boosters clustered around
expected to continue working for 10 years. These satellites can be the second stage. Each one contains an RD-107A engine. At the
launched aboard a Proton rocket, or in the case of Sunday’s launch, same time, the second stage, also known as Blok-A ignites its RD-
aboard a Soyuz. The K series of satellites has a major improvement 108A engine that includes additional vernier motors to help steer
over older versions. It includes the first unpressurized GLONASS as the rocket ascends. All three stages burn RG-1, the Russian
satellites, allowing them to work solely in the vacuum of space. In equivalent to the rocket grade kerosene known as RP-1 used in
addition, it has a reduced mass of only 750 kg (1,650 lb) compared the US, and use liquid oxygen as an oxidizer. After 118 seconds,
to the older M series which has a mass of 1,450 kg (3,200 lb). the first-stage boosters are depleted and separated with the help
The three-stage Soyuz-2.1b vehicle was topped with a Fregat of vented gases to push them away from the vehicle. This results
in a pattern known as the “Korolev Cross,” named after the chief
designer of the Soyuz. At around three and a half minutes into the
flight, the fairings protecting the GLONASS satellite separated as
the rocket escaped the thicker portion of the Earth’s atmosphere.
Four minutes and 45 seconds into the flight, as Blok-A neared the
end of its burn, the third stage, known as Blok-I, fired its engine
while Blok-A is still lit. This process is known as hot staging. Many
Russian rockets use this procedure to ensure Blok-I remains settled
through separation and prevent the need for additional separation
motors. A few seconds later, separation occurred. Blok-I continued
to burn for an additional five minutes before shutting down, placing
the satellite into a parking orbit. At this point, the Fregat upper stage
and GLONASS-K1 No. 17 were released from Blok-I and separated
from the launch vehicle. The Fregat used storable propellants,
unsymmetrical dimethylhydrazine and dinitrogen tetroxide, and
was fitted with an S5.98M engine which can be restarted multiple
times. The engine performed three different burns over three and a
half hours to place the spacecraft into its final orbit. At that point,
GLONASS-K1 No. 17 separated from the Fregat. Once in this final
orbit, the satellite is expected to be designated Kosmos 2559. This
marks the 13th Soyuz rocket so far this year and the fourth of the
Soyuz-2.1b.

112 SEPTEMBER-OCTOBER 2022