Soyuz Launch Vehicle
1971-1975 Study
1. The Original Version—A
Sputnik Series SL-1, SL-2
Some time in the early 1950's a large Soviet rocket engine was developed for use in connection with the first ICBM, and it may have been considered even at the outset for space work as well. The Russians designated this the RD-107. The engine burns kerosene and liquid oxygen, uses a single shaft turbine assembly to pump the oxidizer and fuel to four combustion chambers with exit nozzles and to two steering rockets. There are auxiliary systems to pump a hydrogen peroxide gas generator and to run a liquid nitrogen to nitrogen gas pressure supply. The engine operates at 60 atmospheres to produce a vacuum thrust of about 102 metric tons with an Isp. of 314 seconds. A variant of' the same engine is called the RD-108, differing from its predecessor primarily in having four steering rockets instead of two, and its vacuum total thrust is 96 metric tons. The first ICBM which also became the launcher for Sputnik 1 was assembled by placing four long tapered tanks of roughly cylindrical shape around a sustainer core. Each of these strap-ons had an RD-107 engine and the central unit had an RD-108. All five units with their 20 main nozzles and 12 steering rockets are ignited on the pad, and as soon as thrust builds up to lift off the pad, the rocket rises. When the boost task is over, the four strap-ons fall away leaving the sustainer core to continue burning for a time.
The total assemblage creates a fairly graceful impression. The central sustainer core. 28 meters long, described from the ground up starts as a regular cylinder, then flares outward, and tapers back again, creating a hammer head effect. This peculiar shape was selected to blend with the four strap-ons which are modified elongated tapered cones. When all five units are strapped together, the result is a fluted pyramid effect with a maximum base diameter of 10.3 meters, including the four stubby fins.
This is the vehicle which the Russians claim first flew as their original ICBM from Tyuratam on August 3, 1957 . (14) Then it was used for the launch of Sputnik 1 on October 4, 1957 and likewise for the next two Sputniks. During that period the rocket had no upper stage, so it was not used very efficiently for payload weight purposes. The entire sustainer core was placed in orbit on these occasions, and one of the blurred Western photographs taken of such a rocket tumbling in orbit definitely suggests its hammerhead shape which has since been revealed by the Russians. Judged by the weight of the last and heaviest of these payloads, the lifting capacity of the rocket was about 2 metric tons to low circular orbit. It is possible that the residual weight of the spent rocket casing was on the order of 6 metric tons.
With the announced weight of Sputnik 1 at under 84 kilograms, it is understandable why Western observers in that period postulated the use of a much smaller launch vehicle than the real one. When people rushed out of doors to see the passing of the first satellites, usually they were really viewing that 28 meter rocket casing, like a Pullman railway sleeper tumbling end over end rather than the spherical Sputnik 1, 0.58 meters in diameter, or even Sputnik 3 which was 3.76 meters long. Sputnik 2 remained attached to its rocket. Some time later, when the United States launched the Project Score satellite in the same mode as Sputnik 2—namely, leaving the payload attached to the spent rocket casing—it injected the entire sustainer portion of the Atlas launch vehicle into orbit. The United States announced achievement of the "world's heaviest satellite to date (3,969 kilograms). The useful payload was actually about 68 kilograms. This provoked Leonid Sedov of the Soviet Union into some testiness, when he pointed out that the total weight in orbit in connection with each of the three Sputnik launches had been in excess of the U.S. weight. The residual Soviet weight has been assumed to be about 6 metric tons, and the Sputnik 2 vehicle which like Score remained attached to the rocket body weighed 508 kilograms for a total combined weight of perhaps 6,508 kilograms.
2. Launch Vehicle with Lunar Upper Stage, A-l
Vostok Series SL-3
Considering the lead times involved in developing space vehicles, it is likely that well before the time of Sputnik, the Russians were designing and building an upper stage to fit on their original model ICBM, and this raised its orbital capacity to over 4,700 kilograms, though its first use was for direct flights to the Moon with a net payload weight of about 400 kilograms.
This upper stage used for the Luna 1, 2 and 3 flights was the first Soviet spacecraft to be put on public display in replica. Mounted on top of the sustainer core by an open truss structure, it measures about 3.1 meters long and has a diameter of 2.58 meters. Strangely to this date the Russians have not announced the designator for the single nozzle engine or given its thrust. Its thrust should be on the order of 10 to 20 metric tons. We are left with a mystery in the Soviet accounts. They reported for some years that the total thrust of all the engines was 600 metric tons. Having then told us that the five engines of the core and boosters had a thrust of 102 metric tons each, by subtraction the upper stage thrust should have been 90 metric tons, which would have put a heavy G load on this stage when it fired. This is the amount of thrust of the Soviet RD-219 upper stage engine, but it has two nozzles, and the lunar stage engine has only one nozzle. When this rocket was used for the direct flights to the Moon, the lunar stage was accelerated to a speed sufficient to send it to the Moon along with the payload. The combined weight of spent rocket and payload was on the order of 1.500 kilograms.
When the Russians were ready to begin test flights leading toward placing man in orbit, they used this same upper stage on the original launch vehicle. It was not until 1967 that a replica of Vostok was put on public display (Paris Air Show), and indeed, the upper stage of that assembly was essentially the same as the earlier unveiled lunar stage of 1959.
It was mentioned that at first Western analysts thought a much smaller rocket had been used by the Russians for the launch of Sputnik1 because that payload weighed only 84 kilograms, and people at first were unaware of the great weight of accompanying rocket stage also in orbit. A second factor in the underestimation was the difference in design philosophy. For example, the early U.S. Atlas missile has such light construction that it must be kept pressurized all the time to keep it from collapsing of its own weight in relation to skin thickness.
This was done to maximize performance for a given size of vehicle. By contrast, when the Soviet launch vehicle arrived by ship at Rouen, France, observers were fascinated to note that the core and boosters were unloaded with cables attached at opposite ends, and workmen could walk the length of the empty rockets. The implication was the Russians did not feel weight-limited, and had built rugged vehicles which still permitted them to carry the payload they wanted, within reasonable limits.
3. Launch Vehicle with Improved Planetary Upper Stage, A-2
Voskhod, Soyuz Series SL-4
The Luna and Vostok version of the standard vehicle did not exploit the total potential of the first stages, and so an improved stage was built which began to fly as early as 1960. Its first public disclosure came in 1961 in connection with the Venus attempts of that year. The Luna upper stage was replaced by a stage 6.6 to 8 meters long. It was able to send about 1,500 kilograms of payload to the Moon, not counting the weight of an escape rocket, and over a period of time the capacity was raised. Without an escape rocket it was used to increase the Earth orbital capacity. The first announced use in Earth orbit was to put up 6,583 kilograms, and subsequently, the capacity has been described by them as 7.500 kilograms maximum. It was used for the pair of Voskhod manned flights, and has continued in use to the present time in the Soyuz manned flights. In addition it is the version most used in the Kosmos program for those flights which perform a military mission followed by recovery after some days.
It is the Soviet practice to disclose information only piecemeal about their vehicles. In the case of the Vostok it was years before they disclosed the thrust of the rockets or their number. The sole statistic beside the orbital weight was an output of 20,000,000 horsepower, not a common measure for describing the power of rockets. As mentioned they later said the combined thrust was 600 metric tons from six engines.
When the Voskhod flights came, they said the rocket had seven engines of 650 metric tons. No replica was put on display, so that analysis in the West was made more difficult. Subtraction of the announced thrust of the five core and booster engines seemed to leave 140 metric tons of thrust for an upper stage of 2 engines. This was not logical for the purposes or for the observed behavior of the fights. It is only in 1975 that we finally have a fresh Soviet statement on this rocket combination. First of all, they have adjusted downward the thrust of the central core rocket to list it at 96 metric tons, giving 504 metric tons for the combined thrust of the core and boosters. Now they list the same upper planetary stage, as used for Soyuz as having a thrust of 30 metric tons. The stage is powered by a single engine with four combustion chambers and nozzles. There is no clue as to how to reconcile the 534 metric tons of combined thrust in Soyuz with the 650 metric tons quoted for the same stages in the Voskhod of many years earlier. We still do not know what the seventh engine alluded to earlier meant, as only six can be counted.
The mystery of why the Soviet listed thrusts ran ahead of normal reality was finally solved in 1975. Maarten Houtman of Amsterdam was talking with a Soviet engineer at the Paris Air Show, and was told that the 600-metric ton figure for thrust was found by adding together the combined thrust of four RD-107 engines at 102 tons each, plus the RD-108 engine at 96 tons, for a total of 504 tons, and then adding to that the thrust of the same RD-108 which continued to burn after the four strap-ons dropped away, making the total of 600. The arithmetic is impeccable, but it seems a most peculiar way to count total thrust, and it still ignores the thrust of the final stage.
A review of the book by Leonid Vladimirov (Finkelstein) shows that he published in 1971 the thrusts of the Vostok (A-l) rocket four years ahead of the 1975 Soyuz disclosures on the same rocket, and he further had information that the mysterious upper stage had a thrust of 11 tons, which is consistent with the RD-119 engine to be discussed presently.
In 1957, Russia (the former Soviet Union) launched the Sputnik 1, the first artificial satellite in the history of mankind, which was a sensational world event. Russia could keep the lead in space missions for a while after their success because of certain special measures. Russia did not start the production of a large rocket through one single effort but started the mission with a rocket consisting of a bundle of small rockets, applying the V-2 technology they received from the Nazis after their occupation.
The Soyuz is an upgraded version of the Vostok which became the first manned space flight in the world by Gagarin in 1964. The Soyuz is called the A-2 (SL-4) and the Vostok is called the A-1 (SL-3) both of which were nicknamed for a manned space ship. The improved vehicles of Soyuz class were already used by various missions including the first manned flight of the Voskhod in 1964 and other experimental flights before the first manned flight of the Soyuz in 1967.
The most active Russian launch vehicle during 1993-1994 was the Soyuz-U2 (including the Soyuz U2 variant). Deri, Korolev's original R-7 ICBM (ISS-6) and the subsequent Sputnik, Luna, Vostok, and Voskhod launch vehicles, the first in 1966 and has since been flown approximately 750 times in various configurations with a reliability of more than 97%. The two-and-one-half-stage launch vehicle burns simple liquid oxygen and a form of kerosene. The first stage consists of a core vehicle powered by a 11D512 (RD-108) main engine and four strap-on boosters with 11D511(RD-107) main engines. The second stage carries a single, 4-nozzle 11D55 (RD-0110) main engine. The Soyuz- U/U2 launcher currently has a LEO payload capacity of approximately 7,300 kg for 52 degree inclination orbits. The Soyuz-U2 upgrade was introduced in 1986 to support the Soyuz-TM spacecraft and has also been used for Progress-M spacecraft and the sixth generation photographic reconnaissance satellites.
5. The Standard, Vehicle with Maneuvering Stage, A-m
Polet SL-5
Late in 1963 and again in 1964, the Russians flew payloads with the name Polet, and These were heralded as but the first ones of a large series. In actual fact, no more flights occurred with exactly the same characteristics, and the name itself was not used again.
What was distinctive about these flights was that they came early enough in the Soviet program and were ambitious enough in performance for their being an application of the A vehicle. They were launched from Tyuratam. Each was advertised to have made extensive changes of altitude and also of orbital plane. However, the amount of plane change was not specified, and it is doubtful that it was very large. Neither flight left a separated carrier rocket in orbit as a guide to how extreme the subsequent maneuvers were of the final payload. So apparently the A-l or A-2 were not used for these launches, but some experimental maneuvering stage which remained attached to the payload. Either this combination did not work out as hoped, or the “m” stage subsequently has been incorporated into other hardware, to be discussed later.
[We now know that the “m” stage was in fact the Polet payload as a proof of principal ASAT stage flight test demonstration flown on the basic “A” booster that would later appear in the coming years as a revised F-1-m Tsyklon-2 payload third last stage of the Soviet ASAT program. The ASAT last stage was a separate enlarged payload different from the RORSAT payload and was really a derivation of the Tsyklon-2 with third stage being the payload last stage. Both ASAT and RORSAT required a longer Tsyklon second stage than that utilized by the standard SS-9 ICBM from which the Tsyklon was derived.]
6. The Standard Vehicle Possibly in an A-l-m, Configuration
SL-5 Series
There were two more engineering test flights which bore at least a partial resemblance to the Polet flights. These occurred in 1965 and 1966 under the labels Kosmos 102 and 125. There were no separated carrier rockets accompanying the flights, and their location of perigee in the southern hemisphere suggested that their lunar type stages had been only suborbital with an integral upper stage firing half way through the first orbit to put the apogee back in the latitude of the launch site. It is a temptation to consider tills a further development of the use of the "m" stage, but without Soviet data, it is not provable.
[We now know that this was the initial flight tests of the F-1-m, Tsyklon-2 upper last stage flown on the “A-1” booster and payload shroud that were later flown as the RORSAT payload. The RORSAT last stage was different from the ASAT last stage payload and was really a derivation of the Tsyklon-2 with two stages plus the RORSAT payload spacecraft. Both ASAT and RORSAT required a longer Tsyklon second stage than that utilized by the standard SS-9 ICBM from which the Tsyklon was derived.]
WITH PROBE ROCKET ADDED, A-2-e,
SL-6 Molniya / Venera
4- The Added Stage Version for Eccentric Orbit and Escape Missions,A-2-e
The A-2 version, just described, was itself a step back from the A-2-e, already partly described. In this version, there was indeed a seventh engine, in contrast to Voskhod and Soyuz. This added stage when used is contained within the shroud which covers the payload. The Russians after Luna 3 used consistently a special technique for their flights which required an extra stage. This was especially important for flights more nearly in the plane of the equator, since the Soviet launch sites are at relatively northern latitudes. The rocket assembly is launched from the cosmodrome to place the interplanetary larger stage plus the payload in low circular Earth orbit, where the burned out stage is separated. During the course of the first orbit as the payload heads northeast across the South Atlantic to cross Africa, a special orbital launch platform, never specifically described as to shape, dimensions, or weight, is oriented and from it the final payload is launched to higher speed by the escape rocket. This probe rocket, after it has done its work, is separated from the payload and flies on essentially the path as the payload. It has not been described in detail in Soviet publications available in the West. However, it was shown diagrammatically in a Soviet pamphlet written in German, "Nachrich-tenbriike in Kosmos" which described Molniya 1. This has subsequently been issued in English: "A Satellite's Overhead". The stage is shown as a stubby cylinder measuring about 2 meters in diameter and perhaps 2.5 meters long. The Royal Aircraft Establishment estimates its length as 2 meters. Soviet payloads which are launched from the orbital launch platforms and given their impetus with this added escape stage also carry a special maneuvering engine for orbit adjustments and smaller verniers for orientation.
When this whole system works, it does a very effective job. The Soviet program is given added flexibility as to launch windows through the technique of orbital launch, and calculations can be made as to the final stage firing in the relative tranquility of the vacuum of space. This flexibility is important for the Russians who have lacked the worldwide network of land-based tracking and control stations which the United States has developed in cooperation with other nations. But the number of steps required to carry out a deep space mission, supported by automatic devices and a few ships, tended to expose these operations to a fairly high failure rate. Assuming that in general Soviet flight successes and failures are comparable to those of the United States because competent people in both countries are applying the same technology, then we see no particular reason why Soviet Earth orbital operations should be any less successful than those of the United States . But deep space work with the platform launch technique presents in fact another story. For example, the United States has made 59 launch attempts for escape missions, of which only 11, or 19 percent, have failed to escape. The Soviet Union has made an unpublished number of attempts to use the orbital launch technique, but we can note that of 65 Earth orbiting platforms carrying payloads intended for the Moon, Mars, or Venus, 20 failed to send their probe payloads beyond Earth orbit, or a failure rate of 31 percent, higher than the U.S. rate. The total failure rate is undoubtedly higher for deep space missions because additional flights presumably did not even attain Earth orbit.
7. The Standard Vehicle Possibly in an A-2-m Configuration
In 1970 and 1971 there were three flights (Kosmos 379, 398, and 434) which have never been adequately explained. In another context, their possible missions will be examined. They behaved a little like regular A-2-e vehicles in that they abandoned an interplanetary type stage in low Earth orbit after their launch from Tyuratam. Later they abandoned some piece of hardware in an eccentric orbit which reached out to approximately 1,200 kilometers. After this a maneuvering engine integral with the payload carried the flight to a distance of between 11,000 and 14,000 kilometers, depending on the flight. It is possible that this was therefore a series of flights using the A-2-m configuration. On the other hand, supposing that the hardware abandoned in an intermediate orbit was an "e" upper stage, then the payload may have incorporated a new fourth stage of high efficiency, and it might be labeled the A-2-e-h combination. Until there are more flights to give us data points, or a Soviet explanation, we may be left with no firm answer possible.
Elsewhere in this chapter, Table 1-10 attempts a synthesis of the data collected in Tables 1-8 and 1-9 to suggest a possible set of relationships among the rocket engines and stages used in different vehicle assemblies. It must be stressed that this is somewhat of an exercise in building a castle of sand. One good wave of new Soviet disclosures even if not crumbling the whole structure would change some of its parapets and towers of speculation.
[Today we know this was a series of highly successful flight test of the one and a half stage Soviet “Lunar Cabina” (Lunar Module) spacecraft for manned lunar landing by one cosmonaut for their manned lunar landing program N1-L3 that did not utilize its lunar braking module bloc-D. There is no evidence of a hydrogen, oxygen powered rocket stage was flight demonstrated through 1975.]
1. SOVIET SPACE PROGRAMS, 1971-75, OVERVIEW, FACILITIES AND HARDWARE MANNED AND UNMANNED FLIGHT PROGRAMS, BIOASTRONAUTICS CIVIL AND MILITARY APPLICATIONS PROJECTIONS OF FUTURE PLANS, STAFF REPORT , THE COMMITTEE ON AERONAUTICAL AND SPACE .SCIENCES, UNITED STATES SENATE, BY THE SCIENCE POLICY RESEARCH DIVISION CONGRESSIONAL RESEARCH SERVICE, THE LIBRARY OF CONGRESS, VOLUME – I, AUGUST 30, 1976, GOVERNMENT PRINTING OFFICE, WASHINGTON : 1976,
14. Moscow Radio. August 2, 1967 0800 GMT.
15. Vladimirov, Leonid. The Russian Space Bluff, London : Tom Stacey Ltd., 1971, p. 83.
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