Featured image credit: ROSCOSMOS
Lift Off Time | October 27, 2023 – 04:00 UTC | 07:00 MSK |
|---|---|
Mission Name | Lotos-S1 n°08 |
Launch Provider | ROSCOSMOS |
Customer | Russian Space Forces |
Rocket | Soyuz 2.1b |
Launch Location | Plesetsk Cosmodrome, Arkhangelsk Oblast, Russia |
Payload mass | ~6,000 kg |
Where is the satellite going? | Low Earth orbit |
Will they be attempting to recover the first stage? | No, this is not a capability of Soyuz |
Where will the first stage land? | Unknown |
Will they be attempting to recover the fairings? | No, this is not a capability of Soyuz |
Are these fairings new? | Yes |
This will be the: | – 4th launch of a Soyuz 2.1b in 2023 – 84th launch of a Soyuz 2.1b variant – 173rd orbital launch attempt of 2023 |
Where to watch | If available, a livestream will be listed here |
What Does All This Mean?
The Russian Federal Space Agency is expected to launch the Lotos-S1 satellite on a Soyuz 2.1b launch vehicle into a low Earth orbit (LEO). The rocket will lift off from the Plesetsk Cosmodrome, in Russia, which will mark the 4th launch of a Soyuz 2.1b in 2023.
How Did It Go?
This mission was fully successful. The rocket lifted off from the Plesetsk Cosmodrome, in Russia, on October 27, 2023 at 07:00 local time.
Lotos-S1
Due to the classified nature of this mission, there is no readily available public information on the specifics of satellite operation and intended purpose. We do know that the Lotos-S1(14F145) satellites are a component of the ELINT satellite system, Liana, which is a Russian space based surveillance system. ELINT is a process which intercepts radio signals and relays information for military analysis.
What Is Soyuz 2.1b?
ROSCOSMOS’s Soyuz is a multi-use medium-lift launch vehicle that was introduced in far 1966 and since then has been the workhorse of the Soviet/Russian space program. It is capable to launch civilian and military satellites, as well as cargo and crewed missions to the ISS. Over the decades, several variants of the Soyuz rocket have been developed. Soyuz 2.1b is one of its latest iterations that belongs to the Soyuz-2 rocket family.
The rocket consists of three stages, all of them are expendable. When launching to the ISS, Soyuz-2 can be flown with either a Progress capsule or a Soyuz spacecraft.
Soyuz 2.1b is about 46.3 meters (152 ft) in height and 2.95 meters (9.0 feet) in diameter. The vehicle’s total lift-off mass is approximately 312,000 kg (688,000 lb). The rocket’s payload lift capacity to low-Earth orbit (LEO) is between 6,600 and 7,400 kg depending on the launch site.
Stages
| First Stage | Second Stage | Third Stage | |
| Engine | 4 RD-107A | RD-108A | RD-0124 |
| Total Thrust | 840 kN (188,720 lbf), sea level 1,020 kN (229,290 lbf), vacuum | 792 kN (178,140 lbf), sea level 922 kN (207,240 lbf), vacuum | 294 kN (66,094 lbf), vacuum |
| Specific Impulse (ISP) | 263 s, sea level 320 s, vacuum | 258 s, sea level 321 s, vacuum | 359 s, vacuum |
Side Boosters
The first stage of the Soyuz 2.1b rocket is composed of 4 side boosters that are powered by RD-107A engines. Each one of the boosters has a conical shape and a dry weight of 3,784 kg. It is approximately 19.6 meters in length, with a diameter of 2.7 meters. Each side booster has two vernier thrusters that are used for flight control.
The RD-107A engine runs on rocket-grade kerosene (RP-1) and liquid oxygen (LOx). The propellants are stored in the pressurized aluminum alloy tanks, the kerosene tank is located in the cylindrical part of the booster, and the LOx one is in the conical section. Each one of those engines have 4 combustion chambers and together they are capable of producing a thrust of 840 kN at sea level and 1,020 kN in a vacuum.
Perhaps, the most spectacular moment of the Soyuz-2 rocket’s launch is the separation of the first stage. It happens approximately 2 minutes after the launch. The boosters perform a pattern, known as the “Korolev cross” (named after Sergei Korolev, a very important figure of the USSR space program and history).
Second And Third Stages
The center core stage is powered by a single RD-108A engine, and the upper stage is fitted with a single RD-0124 engine. Both of these engines run on RP-1 and LOx and have 4 combustion chambers. The second stage is 27.1 meters long, with a diameter of 2.95 meters, and a dry mass of 6,545 kg. It has 4 vernier thrusters for three-axis flight control.
The third stage of a Soyuz-2 rocket has a height of 6.7 meters, a diameter of 2.7 meters, and a dry mass of 2,355 kg. One interesting thing about the RD-0124 engine on this stage is that it starts its ignition sequence prior to stage separation. This process is called “hot fire staging”.
Fregat Upper Stage
Flight qualified in 2000, the Fregat upper stage is an autonomous and flexible stage that is designed to operate as an orbital vehicle. It extends the Soyuz launcher’s capability, covering a full range of orbits (LEO, SSO, MEO, GTO, GEO and Earth escape). Fregat is independent of all the other stages, as it has its own guidance, navigation, attitude control, tracking, and telemetry systems. The S5.92 engine burns storable propellants – UDMH (unsymmetrical dimethylhydrazine) and NTO (nitrogen tetroxide). The Fregat upper stage is encapsulated in a fairing with the payload and a payload adaptor/dispenser. Upgraded Fregat-M has additional ball-shaped compartments on top of its propellant tanks, which allows to increase the load capability of the propellant.
