The emergency rescue system of the crew of the Soyuz launch vehicle

The most significant difference between the Soyuz launch vehicle and the previous R-7 carriers designed for manned flights was the new type of emergency rescue system (SAS) developed under the direction of Korolev in OKB-1 , designed to save the crew in case of launch vehicle accidents from the moment of activation САС (15 minutes before the launch of the launch vehicle) and at any flight site.

The Soyuz launch vehicle was designed for launching spacecraft of the same name Soyuz into space orbit.

The Soyuz spacecraft consists of three compartments - a household, instrument-aggregate and descent vehicle (SA). A spacecraft with astronauts is in the middle of the ligament, therefore, in order to save the crew, it is necessary to remove the ligament from the main compartment of the rocket and the spacecraft, together with the head fairing (GO).

The arrangement of the CAC propulsion systems according to the pulling pattern - on top of the bar, and not in the lower part, under the spacecraft, was dictated by considerations of weight and fuel economy, since immediately after the carrier rocket is set to a sufficient height, the bar along with the engines is fired off from the fairing ^[2] .

Solid-propellant rocket engines (RDTT) of separation are installed on the flaps of the head fairing of the Soyuz launch vehicle, leading the detachable head unit with the crew, in the area between the compartment of the CAC propulsion system and the discharge of the head fairing. At the top of the module, there is an auxiliary engine for withdrawal towards the head fairing after the main solid-fuel engine of the compartment has been triggered ^[2] .

The solid propellant propulsion system САС consists of two multi-nozzle blocks of solid propellant engines (for separation and removal of a detachable head unit) and four small control solid propellant motors. The ship is connected to the head fairing by three supports that surround the descent vehicle and “rest” on the lower frame of the household compartment. On this frame, the descent vehicle "hangs" as it were.

The force from the SAS remote control to the SA is transmitted through two power belts (upper and lower) and a special lodgement in which the descent vehicle is installed. There is also an additional mount in the upper part of the head unit that fixes the household compartment.

In 1965, during the development of the SAS, it turned out that in the event of an accident, the discharge of civil defense is entirely impossible without a strong blow to the instrument-aggregate compartment. To eliminate this problem, it was decided to divide the fairing into two parts with a transverse joint, so that when the CAC remote control is triggered, only its upper part is separated. In this case, the lower part of the GO, together with the instrument-and-aggregate compartment of the spacecraft, remained with the rocket.

To maintain stability in flight on the GO, four lattice stabilizers were installed. Such a structural and layout scheme of the detachable head unit of the SAS became the basis for all modifications of the Soyuz and Soyuz spacecraft in the future.

The emergency rescue system includes ^{[3] [4]} :

• CAC automation (automation units, time-program device, power supplies, gyro devices, onboard cable network);
• propulsion system of emergency rescue system (ДУ САС);
• head fairing engines (RDG);
• CAC mechanisms and assemblies located on the head fairing (trellised stabilizers, lodgements, upper supports, emergency joint mechanisms, fire protection system, optical visor blister separation means).

Depending on the moment of the accident, crew rescue is provided for in one of three main programs, corresponding to the three main flight sections ^[5] :

• in the first section (from the moment 10-15 minutes before the launch of the rocket and to the discharge of the head fairing with the propulsion system CAC);
• in the second section (in the time interval between 161 and 522 seconds of flight);
• in the third section (from 522 seconds, but before reaching the target orbit by the spacecraft).

In contrast to the emergency shutdown operations of the Space Shuttles , the SAS Soyuz does not provide a scenario for the spacecraft to go into orbit, since the third stage of the launch vehicle has one propulsion system and a limited fuel supply, insufficient for a second attempt to reach the target orbit ^[6] .

Scenario of the first flight phase

The program is used from the moment the CAC is switched to standby mode at the launch position (10-15 minutes before the launch of the rocket) until the head fairing is reset, along with which (or somewhat earlier) the solid propellant propulsion system is reset. According to this program, at the time of the accident, the alarm on the astronaut’s console is turned on, the propulsion systems of the launch vehicle are switched off accidentally (only after accidents after 20 from the flight), the spacecraft is divided at the junction between the descent vehicle and the instrumentation and auxiliary compartment, and the power connections that hold the SA are fixed and a household compartment inside the head fairing. Next, the transverse joint was separated in the middle part of the head fairing and lattice stabilizers were revealed. Simultaneously with the disclosure of stabilizers, the main solid-fuel engine starts.

In the process of operation of the main engine of the remote control SAS, steering steering engines are switched on, forming the path of removal of the detachable head unit. A detachable head unit must rise to a height of not less than 850 meters and be withdrawn from the launch site to the side by no less than 110 meters ^[1] .

In the region of the top of the withdrawal path, the lander is separated from the household compartment and the solid-fuel separation engine is switched on, which ensures that the head fairing along with the household compartment is removed to a safe distance from the lander. After separation, the descent control system is activated, which should damp the angular perturbations of the capsule with the astronauts obtained during separation. Then, at the command of the program-temporary device (in case of an accident at low altitudes) or at the command of a barometric sensor (in case of an accident at high altitudes), the parachute system is launched. In the event of an accident, in the first 26 seconds of the flight, the descent vehicle is supposed to land on a reserve parachute , and after 26 seconds of the flight, on the main one. During the parachute descent, the on-board systems are prepared for landing.

When the solid propellant is triggered, the crew can experience overloads of up to 10g. The thrust of the solid propellant rocket engine is 76 tf and the operating time is less than 2 seconds.

In this scenario, the T-10-1 Union was saved, the launch vehicle of which exploded right on the launch pad ^[5] .

Scenario of the second leg of the flight

The program is triggered in case of accidents between 161 and 522 seconds of flight. According to this program, at the time of the accident, the alarm on the astronaut’s console is turned on, the propulsion systems of the launch vehicle are switched off accidentally, the onboard systems of the descent vehicle are put into emergency operation.

After a certain time delay, the household compartment was separated, and then the descent vehicle and the instrument-aggregate compartment were separated. After separation, the descent control system deploys the descent vehicle in the pitch plane and, upon entering the atmosphere, provides its descent in the “maximum aerodynamic quality” mode. With a further decrease, the landing system works according to the regular program.

Scenario of the third leg of the flight

In an accident after 522 seconds and before entering orbit, the spacecraft compartments are divided according to the standard scheme, but the descent passes along a ballistic trajectory, and overloads can exceed 10g.

December 14, 1966 - Union 7K-OK No. 1

Unmanned. After the launch was canceled for technical reasons, a command was issued to trigger the CAC at the start. SAS worked flawlessly, but the separation led to a fire and explosion of the LV, as well as the death of one of the officers of the launch team ^[7] .

September 27, 1967 - Union 7L-L1 (4 L, Probe-4A)

This was the first attempt at an unmanned overflight of the Moon , but the flight ended in a CR accident 65 km from the launch site. SAS worked normally, and the descent vehicle landed intact (if it were a manned flight, the crew would remain alive) ^[8] .

November 22, 1967 - Union 7K-L1 (4 L, Probe-4B)

The second attempt at unmanned overflight of the moon . Failure of the Proton launch vehicle 4 seconds after the launch of the second stage. SAS drowned out the rocket engines and saved the lander. The carrier fell 300 km from the cosmodrome ^[9] .

January 20, 1969 - KK 7K-L1 (Probe-7A)

When trying to launch the ship in unmanned mode, the Proton launch vehicle exploded. SAS drowned out the rocket engines and saved the lander.

July 3, 1969 - N-1

Product No. 5L with an unmanned ship 7K-L1A / 7K-L1S (11F92) "Zond-M" (prototype LOK) and a model of the lunar landing ship LK (11F94) of the L3 complex. The launch took place on July 3, 1969 and also ended abnormally due to the abnormal operation of the peripheral engine No. 8 of block A. The rocket managed to fly upright 200 meters - and the engine shutdown began. In 12 seconds, all engines were turned off, except for one - No. 18. This only working engine began to rotate the rocket around the transverse axis. At the 15th second, the SAS powder engines fired, and the descent vehicle, torn from the carrier, successfully flew away. At the 23rd second, the carrier fell flat on the launch site.

April 5, 1975 - Soyuz-18-1

At the 261st second of the flight, when the separation of the second stage of the rocket was supposed to happen, this did not happen, and the rocket began to swing. The automatic separation system of the returning device from the rocket worked. During the descent, the astronauts experienced a peak overload of 20 g (according to other sources - 21.3 g and even 26 g). The device landed south-west of the city of Gorno-Altaysk , at an altitude of 1200 m on the snowy slope of Mount Teremok-3. Cosmonauts Vasily Lazarev and Oleg Makarov were rescued ^[5] , however, as it turned out later, Lazarev’s health was rather badly damaged due to large overloads.

September 26, 1983 - T-10-1 Union

The launch vehicle explosion on the launch pad due to a malfunction in the lubrication system of the first stage gas generators. There were no casualties during the accident. Pyro locks worked, and the descent vehicle rushed away from the rocket, which after 2 seconds after the shooting fell apart, collapsing down into the pit of the launch pad . During the four seconds of operation of the solid propellant engines of the CAC, the astronauts Vladimir Titov and Gennady Strekalov experienced overloads from 14 to 18 g without health effects, rising to a height of 650 meters and then by inertia to 950 meters, where the parachute opened. After 5 minutes, the descent vehicle with the astronauts landed four kilometers from the scene of the accident. As of 2018, this is the only case when the CAC propulsion system was deployed on the head fairing to save the crew ^[5] .

October 11, 2018 - Union MS-10

An emergency shutdown of the engines of the second stage occurred at the 165th ^[10] second after the separation of the side blocks of the first stage from the central block of the second stage. A few seconds before this, the main engine of the SAS was regularly shot, so the evacuation of the descent vehicle was provided by additional solid fuel engines located in the head fairing. The crew included Roscosmos cosmonaut Alexei Ovchinin and NASA astronaut Tyler Hague , the third place on the ship was taken by a container with cargo (the place was intended for the subsequent return of the astronaut from the UAE : Khazza al-Mansouri or Sultan Al-Neyadi ).

• The Soyuz launch escape system: an overview (Russian) . www.space2010.ru . Date of treatment January 12, 2019 . NASA Presentation

• How does the emergency crew rescue system of the Soyuz spacecraft - Infographics (neopr.) . TASS (October 11, 2018). Date of appeal October 12, 2018.