UR-700 Launch Vehicle for Direct Lunar Landing Mission
Credit: © Mark Wade
Status: Cancelled 1968. Payload: 151,000 kg (332,000 lb). Thrust: 56,500.00 kN (12,701,700 lbf). Gross mass: 4,823,000 kg (10,632,000 lb). Height: 76.00 m (249.00 ft). Diameter: 17.60 m (57.70 ft). Apogee: 200 km (120 mi).
TsKBM began work on the UR-700 launch vehicle in 1962. Variants were studied with 70 to 175 metric tons payload, and rocket stages of various thrust levels, including nuclear stages. The conclusion was reached that a direct lunar landing would require a payload of 130 to 170 metric tons. Principles of the final design were:
The configuration of the UR-700 was driven by the requirement that its components be rail-transportable and modular. In this way the launch vehicle could be built and completely tested at the Khrunichev factory in Moscow and then quickly assembled for launch at the Baikonur cosmodrome in Kazakhstan. Chelomei's solution was to use a basic module of the largest possible rail-transportable diameter (4.15 m diameter and a sphere radius of 2.265 m at the base). This could consist of an oxidizer tank, or a fuel tank with the engine installation. The design had to meet requirements from two sides. On the one hand, the maximum length and diameter of the modules was dictated by the size of rail wagons and platforms, and existing rail tunnels, waterways, and turntables. On the other hand, the size of the rocket stage, and its corresponding volume and mass, were driven by the necessary technical characteristics of the UR-700. The UR-700 requirements greatly affected the design of the UR-500 Proton, since the Proton core stages would form the basis of the UR-700 modules and upper stages.
The basic configuration of the UR-500, taking into account the UR-700 requirements, was selected in January 1962. While approval to proceed with development of the UR-500 came in April 1962, no such go-ahead was received for the UR-700. However Glushko was authorized to proceed with development of the enormous RD-270 engines required for the UR-700. Chelomei unveiled his UR-700 project to Khrushchev at a meeting at Baikonur in September 1964, during which he showed a model of the rocket to Khrushchev. Korolev was also present at the meeting, and a decision was taken to examine the potential of the proposal. Unfortunately for Chelomei, Khrushchev was ousted from power a month later, and all of his projects came under scrutiny by the new regime.
The next chance for the project to be considered came on 16 November 1966, when a Keldysh-headed expert commission considered the state of the N1 program. Korolev had died earlier in the year, and once again Glushko, Chelomei, and Yangel advocated development of the UR-700 or R-56 in lieu of the N1. While it was agreed that engine development and studies of these launch vehicles could continue, the government decree issued approved Mishin's draft plan for the first lunar landing using the N1.
Chelomei signed the UR-700 design directive documents on 21 July 1967. Development of the UR-700 was undertaken in accordance with decree 1070-363 of the Soviet Ministers and Central Committee of the Communist Party on 17 September 1967 and MOM decree 472 of 28 September 1967. Study index number 4855CC by TsNIIMASH in 1966 showed that any development of improved versions of the N1 would be practically equivalent to design and qualification of a new rocket, while the UR-700 modular approach allowed a range of payloads without requalification. The UR-700/LK-700 combination could support the DLB lunar base better, as well as Venus/Mars manned flybys and Mars landing expeditions.
Project plan was as follows:
Following the explosion of the first N1 in January 1969, Pilyugin was called to a meeting at the Kremlin. Chelomei was again proposing the use of his UR-700 in the place of the N1, and a flight to Mars using an even larger version of the launch vehicle. Afanasyev was preparing a decree along these lines. Pilyugin refused to participate in this 'adventure'. Everyone thought that the UR-700/LK-700 project represented a duplicative effort from the beginning.
Tyulin was less concerned about the UR-700. He noted that Mishin was deep into the development of the N1, and the UR-700 was only being discussed as being promoted as a draft project. The original UR-700 documents had been sent to archives in 1964 when the N1-L3 was approved. At a reception shortly thereafter, Chelomei told Chertok that if the UR-700 had been selected instead of the N1, Russia would already be on the moon. Three stages of the UR-700 had already been developed and flown as the UR-500 Proton. Only the RD-270 engines of the first stages would have to have been developed. The configuration of the UR-700 for the lunar mission consisted of 9 RD-270's with 5760 metric tons thrust at sea level. This would have delivered 140 metric tons into low earth orbit.
Chertok asked Chelomei what would happen if, God forbid, such a booster exploded on the launch pad. Wouldn't the entire launch complex be rendered a dead zone for 18 to 20 years? Chelomei's reply was that it wouldn't explode, since Glushko's engines were reliable and didn't fail. Aside from that, these propellants had been used in hundreds of military rockets, deployed in silos, aboard ships and submarines, with no problem. Fear of these propellants was irrational. Related propellants were used by the Americans on the Apollo manned spacecraft.
Nevertheless Chelomei's bureau continued to study a number of different ways of clustering the basic modules until 1974, when the project was finally and definitively suppressed.
The RKS Rocket-Space System was designed for direct landing on the moon without docking in earth or lunar orbit. It consisted of:
The UR-700 consisted of first and second stages mounted to the core in parallel, while the third and fourth stages were arranged in tandem in the core. The first stage consisted of six 4.15 m diameter modules in pairs; the second stage of three 4.15 m modules; the third of a core 4.15 m module with three 1.6 m diameter tanks.
The RD-270 engine was used in all nine modules of the first and second stages, operating at 103% thrust at lift-off. At lift-off all nine RD-270 engines would fire; the engines of the second stage would feed from propellant tanks in the forward section of the first stage modules. Therefore at separation of the six first stage modules, the propellant tanks of the three second stage modules would still be full. In one variant of the design, each module of the first and second stages would have only one propellant tank, instead of separate oxidizer, fuel, and stage two propellant tanks. A cross-feed system would be used to feed all engines from all tanks. This would result in a more complex but lighter system with improved propellant utilization. Solid rocket motors were used to separate the modules at an angle of 15 to 20 degrees upon propellant depletion.
Each block consisted, from aft to forward, of: an engine section, fuel tank, intertank section, oxidizer tank, upper intertank section, cross-feed propellant tank for fuel or oxidizer pumped to the first stage, and conical aerodynamic fairing. Due to their differing volumes, the oxidizer tanks extended into the conical upper aerodynamic fairing, while the fuel tanks were contained in the cylindrical portion of the rocket block. In the lower part of the block was the autonomous conical engine block, which transmitted loads from the RD-270 engines to the booster structure. The propellant tanks were of AMg6 aluminum alloy and were chem-milled with a waffle pattern to reduce weight and provide rigidity.
The third stage was adapted from the Proton UR-500 first stage. The overall stage was 80% of the mass of the Proton first stage, but with only three external tanks and three engines in place of the six larger-diameter tanks and engines of the Proton. The 4.15 m diameter core tank was shortened a bit compared to the Proton, and the three 2.0 m diameter external tanks lengthened. The three RD-254 engines were versions of the UR-500's RD-253 with high-altitude nozzles. Loads were transmitted from the second to the third stage using three conical structures. The third stage was equipped with ullage engines to provide enough G forces after separation from the second stage to allow propellants to settle and the three main engines to start
The UR-700's guidance system was by KBEM MOM and used digital computers. The booster was maneuvered using gimbaled engines. The gimbals' actuators were by TsNIIAG. The RD-270 engines on the first stage could be gimbaled 8 degrees outward, the third stage engines 3 degrees.
The rocket blocks were connected using a coupling system developed by KB Arsenal. The rocket blocks were connected together at four places: at the top of the engine section, where the main loads were transmitted, at the intertank section, at the top of the block, and at the location of the crossfeed propellant lines. NIIP MAP developed the SOB system of expendable tank support and KSURT complex propellant utilization system. At first stage separation these systems changed over the gas and pneumatic systems, shutdown the propellant valves, and triggered the pyrotechnics for stage separation. The second stage used the SKU propellant utilization system developed for the UR-500.
The UR-700 and LK-700 would be assembled at the existing technical positions of the N1 launch complex. However KBOM did design a launch complex for the UR-700 if the decision was taken to build a dedicated launch site. On the pad the UR-700 would be connected using triple umbilical lines.
Missions and Payloads
The draft project selected a preferred launch vehicle configuration using RD-270 engines, delivering 150 metric tons in low earth orbit, which could place two cosmonauts on any point of 88% of the visible lunar surface.
Chelomei felt that the lunar orbit rendezvous approach of Korolev's N1-L3 system compromised crew safety to an unacceptable degree. Primary features of his design were:
The later DLB lunar base would require 80 metric tons per year of payload delivered to the surface starting in 1975, followed by 150 metric tons per year after 1980. Versions of the UR-700/LK-700 could handle this more easily than modifying the N1. Later versions of the UR-700 could use high energy propellant or nuclear-powered upper stages
Lunar versions of the Almaz OPS would be placed in lunar orbit to conduct detailed reconnaissance of the surface using manned assistance. The OPS would also be used as a command post to co-ordinate the work of lunar surface operations and organize rescues in the case of emergencies on the surface.
The TsNIIMASH study recommended the UR-700 over the N1 for these later operations. The UR-700 would also be used for:
LEO Payload: 151,000 kg (332,000 lb) to a 200 km orbit at 51.00 degrees. Payload: 50,000 kg (110,000 lb) to a translunar trajectory.
Stage Data - UR-700
|UR-700 / RD-350 Russian heavy-lift orbital launch vehicle. UR-700 with high energy upper stage consisting of 3 x RD-350 LF2/LH2 engines with a total thrust of 450 metric tons. Usable third stage propellant 350 metric tons, payload increased to 215 metric tons|
|UR-700 / RO-31 Russian heavy-lift orbital launch vehicle. UR-700 with high energy upper stage consisting of 7 x RO-31 Nuclear A engines using LH2+Methane propellants with a total thrust of 280 metric tons. Usable third stage propellant 196 metric tons, payload increased to 230 to 250 metric tons|
|UR-700 / 11D54 Russian heavy-lift orbital launch vehicle. UR-700 with high energy upper stage consisting of 9 x RD-54 / 11D54 LOx/LH2 engines with a total thrust of 360 metric tons. Usable third stage propellant 300 metric tons, payload to a 200 km, 51.5 degree orbit increased to 185 metric tons|
UR-700 lunar landing launch vehicle - From left: cutaway and bottom views; cutaway of core vehicle after six external stage one modules and shrouds were jettisoned; external view. The cutaway shows the arrangement of N2O4 oxidiser tanks (green) and UDMH fuel tanks (orange). The six outer 4.1 m diameter modules contained fuel and oxidizer tanks for stage 1 and fuel or oxidiser tanks for the three core modules. After propellant depletion, the six outer modules would separate, leaving the three core modules to continue their burn. The third stage, based on the Proton first stage, placed the LK-700 spacecraft into a 200 km earth orbit. The LK-700 was equipped with four nearly identical clustered stages and a lunar landing/ascent stage. The three outer stages fired to place the spacecraft on a translunar trajectory. The inner core stage was used for midcourse corrections, braked the spacecraft into lunar orbit, and then again until it was just above the lunar surface. The ascent stage performed the final soft landing on the moon and then, using the landing legs as a launch platform, launched the LK-700 capsule back towards the earth.
Credit: © Mark Wade
RD-270 Rocket Engine - largest single-chamber engine ever developed in the Soviet Union.
Credit: © Dietrich Haeseler
|RD-0410 NTP Engine|
RD-0410 Nuclear Thermal Engine
Credit: © Dietrich Haeseler
Appearance of the LK-700 spacecraft at each phase of its direct lunar landing mission.
Credit: © Mark Wade
The RD-270 engine was proposed for Chelomei's UR-700 and Yangel R-56 lunar landing launchers in competition to Korolev N1. The RD-270 was in the same class as the F-1 engine developed for America's Saturn V launch vehicle, but burned storable but toxic propellants.
Chelomei's TsKBM began work on the UR-700. The conclusion was reached that a direct lunar landing would require a payload of 130 to 170 tonnes. Initial LK-700 spacecraft designs were derived from the 'Raketoplan' family of manned modular space vehicles. Korolev's N1-L3 design was selected in 1964 for the manned lunar landing, but the UR-700 would surface again when the N1 encountered delays.
Following the August decree that gave the circumlunar project to Chelomei and the lunar landing project to Korolev, further work on development of the UR-700 by Chelomei was cancelled. However development of the RD-270 engine was continued and Chelomei continued to do UR-700 design studies.
Kamanin accompanies 17 generals and other officers of the VVS in a tour of Chelomei's OKB-52. Chelomei spends five hours personally acquainting the visitors with his bureau's space technology capabilities. It was the first in-depth meeting Kamanin and Vershinin have had with Chelomei, despite meeting with him occasionally since 1961. They have mainly interacted with Korolev and now Mishin. Additional Details: here....
Development of the LK-700 manned lunar landing spacecraft was undertaken in accordance with decree 1070-363 of the Soviet Ministers and Central Committee of the Communist Party on 17 September 1967 and MOM decree 472 of 28 September 1967. Study index number 4855CC by TsNIIMASH in 1966 showed that any development of improved versions of the N1 would be practically equivalent to design and qualification of a new rocket, while the UR-700 modular approach allowed a range of payloads without requalification. The UR-700/LK-700 combination could support the DLB lunar base better, as well as Venus/Mars manned flybys and Mars landing expeditions. Work would continue through the mock-up stage until 1974.
As the only remaining contender for the Aelita design competition, Chelomei proposes a Mars flyby using an MK-700 spacecraft. A crew of two would be sent on a two year mission in a single launch of a UR-700M booster. The spacecraft would have a mass of 250 tonnes in low earth orbit and be equipped with an RD-410 nuclear engine.