Proton

Khrunichev State Research and Production Space Center * ROSKOSMOS * International Launch Services
 

The rocket UR 500 (later Proton; Proton - K) was developed and first built as IBCM. The design office CHELOMOI (OKB-52) was responsible for its development. In the years 1965 - 1966, the rocket was used for the transport of heavyweight scientific payloads in the earth orbit (Proton 1 to 3).
The rocket consists of two stages. The constructive solution of the first stage is unusual. Six separate boosters which serve as fuel tanks (UDMH) with a revolving engine RD-253 each, are grouped around a central oxidizer tank (Nitrogen Tetroxide). After the boosters’ ignition, the oxidizer is conveyed from the central tank. The engines are protected by heat shields. The second stage uses a group of single chamber engines, four RD-465 (-0210) engines and one RD-468 (-0211) engine.
After 1966, the IBCM was developed to a three-stage and four-stage SLV. First, the burning times of the second stage were extended due to an increased amount of fuel in tank which now came to a total of about 156.1 tons instead of 121.7 tons. Moreover, a third stage was added which was equipped with one single chamber engine RD-0213 and four Vernier engines RD-0214 which altogether provided 31 kN of thrust (= RD-473 or RD-0212). In the following period this three-stage version was exclusively used to transport payloads of up to 20 tons and more in a LEO (Low Earth Orbit). Among these were the space stations Salut, Mir, the military Almaz and TKS modules, and two modules for the international space station ISS etc.
For the lift-off of geostationary satellites, interplanetary and moon probes as well as military communication satellites of the GLONASS-type, a fourth stage called Block D (later DM) is necessary.
The Block D (later DM) has been a standard until the present day. It was developed in the design bureau OKB-1 as an upper stage for KOROLOV's moon rocket N-1. The stage is equipped with a single chamber engine RD-58 (M) = l1D58 (M). A mixture of Kerosene and Oxygen was chosen as propellant. A thruster of Vernier engines (SOZ) is provided with the extra propellant UDMH/Nitrogen Tetroxide. Fundamentally, the following versions of the Block D exist:
 

The four-stage Proton - K was launched for the first time (1967 - 1970) almost exclusively for KOROLOV's programme for the manned landing on the moon (7K-Ll; T1K). The first lift-off of such a test-vehicle took place on 10.03.1967 (Kosmos 146).
CHELOMOI's alternative moon project with the UR 500 and the UR 700 was not enforced. Instead, KOROLEV’s programme with the N-1 was preferred
After the outlook of the moon programme, a strengthening of interplanetary and unmanned moon probes was started. After 1974, geostationary communication satellites (Ekran, Raduga, Horizont) as well as several military satellites of the types Uragan, Prognoz, Geizer and civil satellites (GOMS, Luch, Ekspress, Kupon) followed.
On the assumption that the production and marketing of the Proton would be organized by the Russian Khrunishev State Research and Production Centre, commercial satellites are launched as well since 1996.
KHRUNISHEV has been working on a further development of the Proton - K (Proton - KM). It is intended to replace the fourth stage (Block DM) by a new cryogenic OHSM (Oxygen-Hydrogen Acceleration Module), which is equipped with the engine KVD-1M, and to alternatively complete it with the Breeze - M (UDMH/Nitrogen Tetroxide) which is already usable. New engine modification for the first stage was designated as RD-275. Increase of thrust - 7.7% (162 ton instead of 150.3 ton), it is allow to increase payload mass on 600 kg. First flight with RD-275 engine  -  October 11, 1995 (Luch-1).

Chronology

Period 1965 - 1966
In these years the heavyweight earth satellites Proton 1 to 3 were transported into LEO (Low Earth Orbit) by a two-stage UR 500 (IBCM) at altogether 4 lift-offs. With regard to the configuration and the exact dates of performance of the rocket, it is only known that the second stage was about 4.3 m shorter as later versions and had 30% fewer fuel.

Period 1967 - 1976
The first four-stage Proton (Proton - K) was first launched on 10.03.1967 with the vehicle 7K-LI for the moon programme (Kosmos 146). The engines of the first stage reached a sea level thrust of 8,844 kN. The extended second stage had about 34.4 tons more fuel. For the additional third stage a single engine of the second stage was used. The restartable engine of the third stage (Block D) was adopted for the moon rocket N-1 which was in development.
At first, the reliability of the Proton - K was small. From 1967 to 1969 a high quota of failures was recorded. Out of 17 lift-offs as part of the moon programme, only 6 were successful. In addition, 25 lift-offs with varying success were altogether registered including interplanetary and moon probes and 6 lift-offs with regard to communication satellites (Ekran, Raduga). Two standard fairings of 7.65 and 8.90 m length and 3.90 m diameter were inserted as payload bays.
In this period, 9 lift-offs were accomplished with the three-stage version without Block D containing Salut/Almaz OP modules and one lift-off containing the earth satellite Proton 4 and a double payload (Almaz capsules).

Period 1977 - 1981
In 1977, all engines of the Proton were increased clearly. The engine system Mk-3 of the first stage now delivered a sea level thrust of 9,196 kN (+ 4%). Besides, a prolongation of the burning time by 680 sec (Block DM) could be achieved at the fourth stage Block D by increasing the mass of propellant from 11.56 to 16.8 tons.
For the purpose of a heliocentric mission, the four-stage version was additionally equipped with a third fairing of 10.4 m length.
From altogether 25 lift-offs with interplanetary probes as well as geostationary satellites, only 3 failures were recorded this time with regard to the types Ekran, Raduga and Horizont.
In this period, 5 lift-offs were accomplished with the three-stage version carrying a Salut module No. 6 and two double payloads (Almaz capsules) as well as two lift-offs with the military vehicles TKS.

Period 1982 - 1994
With the introduction of the engine system Mk-4 for the first stage and a further increase of the specific impulses of all stages, the Proton was further improved. The sea level thrust of the 6 engines (RD-253) could be clearly increased to 9,467 kN (+ 3%).
From 1982 to 1994, only six total failures were registered at altogether 128 launches of interplanetary probes and geostationary payloads etc.
For the lift-off of the space probes Granat, ASTRON, Phobos and Venera, a fairing of 10.4 m length and 3.9 m diameter was used.
In this period 9 lift-offs were accomplished with a three-stage Proton, which transported the Salut 7, the Mir space station, the Moduls Kristall and Kvant-2, as well as 5 military Almaz-modules.

Period 1995 - 1999
In 1995, the first stage of the Proton was equipped with a further-improved engine RD-275 (=Mk-5; modified RD-253). It provided a sea level thrust of 9,534 kN (+ 0.7%). Analogous, the thrust of the engines of the second and the third stage were likewise improved slightly. First flight with RD-275 engine  -  October 11, 1995 (Luch-1).
The launched payloads have to be taken individually with regard to the digest appended.
On 28.04.1996, a new fairing (10 m x 4.35 m) was first used for the lift-off of commercial geostationary satellites (ASTRA). Since then, the Khrunishev State Research and Production Centre is responsible for the construction and marketing of the Proton.

Period since 2000
KHRUNISHEV works on a further improvement of the Proton - K (Proton - KM). The performance of the engine RD-275 should once more be clearly increased by altogether 7%.
It is planned to complete the fourth stage Block-DM with a new cryogenic stage OHSM (Oxygen-Hydrogen Acceleration Module) with the engine KVD-1M and the smaller Breeze-M (UDMH/Nitrogen Tetroxide). Furthermore, Block DM is used for the Proton - K and, as an alternative, the Breeze-M is used. Due to the application of the Block DM, a commercial fairing (10 m x 4.35 m) and a standard fairing (10.4 m x 4.1 m) can be disposed of. In accordance with the application of the Breeze-M, a standard fairing of 11.6 m length and 4.35 m diameter is used. Due to the application of an adapter of 1.6 m length, which is included in the Breeze, the fairing extends over a length of 13.2 m.