156 lines
10 KiB
Plaintext
156 lines
10 KiB
Plaintext
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PRESENT DAY SOVIET LAUNCH VEHICLES
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Although most observers of the exploration of space are quite familiar
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with the various US launch vehicle families (Atlas, Titan, & Saturn),
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their Soviet counterparts are still a mystery to most Western analysts.
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This shroud of secrecy is encouraged by the Soviet government which, for
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various reasons, has released little information on these launch
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vehicles. However, given the few tidbits of data available from news
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photos, orbital elements, and the rare Soviet publication, it is now
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possible to describe the history and capability of the Soviet present
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arsenal.
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The following is a summary of the known major Soviet rocket engines and
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their major characteristics. (Vacuum thrust is given in metric tons).
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Number of Vacuum Chamber Specific Principal
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Name Chambers Thrust Pressure Impulse Propellents Use
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------------------------------------------------------------------------
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RD-100 1 30 234 Alcohol/LOX R-1
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RD-103 1 55 28 245 Alcohol/LOX SS-3
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RD-107 4 102 60 314 RP-1/LOX A Class
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RD-108 4 96 52 315 RP-1/LOX A Class
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RD-111 4 166 80 317 RP-1/LOX SS-10??
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RD-119 1 11 80 352 UDMH/LOX B Class
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RD-214 4 74 45 264 RP-1/Nitric Acid B Class
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RD-216 4 177 75 290 UDMH/Nitric Acid C Class
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RD-219 2 90 75 293 UDMH/Nitric Acid SS-9??
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RD-253 1 ? 400 ? UDMH/N2O4 D Class
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As is well known, the Soviets began rocket research on their own
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before the Second World War. The first liquid fueled engine developed
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by Gird, an amateur rocket club, was called the ORM-1, and had the
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distinction of being able to use both cryogenic and storable fuels, an
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ability the Soviets utilized in later vehicles. This small program was
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greatly aided by the capture of German V-2 rockets and scientists in
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1945. The Soviets, as did the US, gained much experience studying the
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German effort. The first post-war Soviet rocket, the R-1, a V-2 clone,
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was launched in 1947, and was powered by the RD-100 engine, the first in
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a long line of large German-influenced engines. In the early 1950's,
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the Soviets developed the Shyster vehicle (dubbed the SS-3 by the US Air
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Force), basically an improved copy of the V-2, for testing Soviet-built
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components in ballistic flights. During this period, the Soviet
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government decided that in order to send 10,000 lb. atomic bombs to the
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US mainland, it would be necessary to develop a large booster, with much
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greater capacity than the Shyster. Thus, Soviet scientists developed
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the techniques of clustering and parallel staging simultaneously. This
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entailed the use of a single turbo-pump per cluster, which led to the
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Soviets adopting a distinct definition of an engine from the Americans.
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The single 50,000 lb thrust engine of the V-2 was clustered in groups of
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4, with a single set of turbopumps for each group. The core cluster of
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4 (called the RD-108 engine, although it used 4 combustion chambers and
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4 exit nozzles) was surrounded by 4 strap-on clusters (the RD-107, but
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basically identical to the RD-108), for a total of 20 first stage
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engines. After the vehicle left the lower atmosphere, the four
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strap-ons were jettisoned, and the core cluster was to carry the warhead
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on a ballistic flight to the US. This vehicle, known to the Air Force
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as the SS-6, and referred to as the A-class launcher by the Library of
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Congress classification system, became the first Soviet satellite
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booster, launching Sputnik in 1957. With a single 12,000 lb thrust
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engine added as an orbital stage, the A class booster was used to launch
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the Vostok capsule. In the mid 1960's, a four chambered, LOX/RP1 fueled
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engine was developed by the design bureau of the late C.A. Kosberg.
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This 50,000+ lb. thrust engine replaced the earlier orbital stage on the
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Soyuz booster.
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Soon after the conception of the A class vehicle, the development of
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the hydrogen bomb enabled much smaller warheads to be built, making the
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large booster obsolete soon after its first launch. The core cluster
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was immediately reconfigured into a missile in its own right, with the
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engine now dubbed the RD-214. In order to decrease launch preparation
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time, the Soviets converted the engine to use storable propellents,
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nitric acid and kerosene, (as in the pre-war ORM-1). This combination
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is much less efficient than the RD-107/108's LOX/RP-1 fuel, resulting in
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a lowered thrust of about 150,000 lbs for the RD-214. The new launcher,
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was deployed in Cuba and Eastern Europe as an intermediate range
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ballistic missile and was dubbed as the SS-4 by the US Air Force.
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Topped by an orbital stage, the hydrazine fueled 24,000 lb thrust RD-119
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engine, this launcher, known as the B class vehicle, is the equivalent
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of of the US Thor/Delta.
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The RD-214 engine was later refined by the use of UDMH instead of
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kerosene for fuel. This new storable fuel increased specific impulse
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for the engine from 264 to 290 seconds. Thrust was increased to 380,000
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lbs. through increase in chamber pressure from 45 to 75 atmospheres.
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The engine was renamed the RD-216, and was installed in the first stage
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of the C class booster. This new vehicle, the equivalent of the Atlas
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launcher, replaced the earlier B class vehicle, and is now the third
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most used space launcher in the world.
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The primitive SS-6 ICBM was ineffective as a weapon. The Soviet
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Union, faced with the need for a storable ICBM, developed a new missile.
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The result was the SS-9, a 2 stage ICBM with 6 thrust chambers, using a
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common turbopump, for the first stage. It is reasonable to suppose that
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the tried and true V-2 design was again used in this new configuration
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with hypergolic fuels for quick launch reaction and storability. It can
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be expected that first stage thrust is greater than the 300,000 lbs that
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the original LOX/Kerosene combination would have produced, due to higher
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efficiency of the Hydrazine/UDMH fuel and Nitrogen tetroxide oxidizer,
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and advances in turbopump technology that the Soviets can be expected to
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have achieved in the 8 year period between the introductions of the A
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class and the F class vehicles. The F class vehicle is roughly
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equivalent to the US Titan missile in payload capacity.
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The Soviets felt that the need existed for a larger space payload than
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the A class, which was limited to 14,000 lbs. in low orbit, could
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provide. A new engine, the RD-253, was developed. One of these engines
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was used in the air-launched core vehicle for the new Proton vehicle,
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with six RD-253 strap-ons as the first stage, giving a total thrust of
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2.5 to 3 million lbs., and a payload capacity of 40,000 lbs. in orbit.
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Details on the upper stage of the Proton are lacking, but it is possible
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to provisionally state that the RD-219 could be a candidate. As the
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RD-219 is claimed to be a second stage engine, with thrust of almost
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200,000 lbs, a probable application for this engine is as the second
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stage of the Proton, if one considers the external strap-ons as a zero
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stage. The tentative configuration of the Proton is thus:
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Zero stage (6 strap-on RD-253) 3,000,000 lbs (approx)
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1st stage (one cluster) 500,000 lbs (approx)
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RD-219 2nd stage 180,000 lbs
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The Proton rocket is used to launch the Salyut space station, as well as
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heavy military payloads.
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It is well known that the Soviets maintain a heavy launch schedule.
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Given the serial production of many thousands of the V-2 class engines,
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which entailed little developmental costs (thanks to the Germans), it is
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reasonable to assume that great economies of scale prevail in their
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space effort. Whereas the US will spend hundreds of millions to develop
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a launch stage that may be used less than ten times (as with the Centaur
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G stage), the USSR has spent little on a family of boosters that
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apparently utilize the same engine design. The U.S. at the beginning of
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the Space Age also developed several boosters from a single engine
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design, the H-1, which grew from 135,000 lbs to 205,000 over twenty
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years. However, the H-1 family was soon superceded by many more
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powerful and more efficient designs, and is now far from being the
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leading edge of engine technology in the U.S. Apparently, the Soviets
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have been content to stay with their basic original design, which has
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grown from less than 40,000 lbs to now over 500,000 lbs of thrust. This
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same paucity of engine research could explain the mysterious lack of a
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liquid hydrogen engine in the Soviet arsenal. Although payload size
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could be greatly increased with even the smallest of cryogenic stages,
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the Soviets are apparently willing to forego the developmental costs in
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favor of keeping program costs to a minimum. Given this low priority
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for engine research, rumors of several new Russian launch vehicles seem
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unfounded, as all of the rumors presuppose Soviet development of liquid
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hydrogen engines that surpass US engines in efficiency. Given the
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present advantage in engine R & D by the US over the Russians, it would
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be highly doubtful that the Soviets will surpass us in engine technology
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in the near term. Making these rumors more dubious is the fact that
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present Soviet launch vehicles can launch all payloads that the Soviets
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have announced for the foreseeable future, including the 1993 asteroid
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flyby. Thus, one can probably count on seeing (or reading about) the
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present group of Soviet vehicles for many years to come.
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*************************************************************************
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Many thanks to Anthony Kenden, Art Bozlee, C.P. Vick, V.P. Glushko,
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Kenneth Gatland, John Parfitt, and many others for their published work
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and their criticism of my earlier entry. Please feel free to correct
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any factual errors that I may have made in this entry, so they may be
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corrected.
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