|R-3 Cutaway - |
7,016 bytes. 51 x 480 pixels.
Development of the long-range R-3 missile was authorised at the same time as the V-2-derived R-1 and R-2 rockets in April 1947. Supplemental authorisation was contained in a government decree of 14 April 1948.The specification was an order of magnitude leap from the other vehicles - to deliver a 3 tonne atomic bomb to any point in Europe from Soviet territory - a required range of 3000 km. To achieve this objective innovative technology was needed in every area of the missile design. Korolev was again in direct competition with the design to the same specification of the captured Germans (Groettrup's G-4).
In selecting a final R-3 design, Korolev examined and discarded several alternatives. An important consideration was the growth potential to achieve ICBM performance (8000 km range with a 5 tonne warhead). The alternatives were:
Korolev's preferred approach was the BN conventional single-stage design. This was down-selected within the bureau in June 1949 and seems to have borrowed a lot from contemporary classified US orbital rocket designs. It required technical advances over the V-2 in every area:
Lift-off mass would be 71.72 tonnes, with a burnout mass of 8480 kg. The warhead would separate at a velocity of 4700 m/s in order to achieve the 3000 km range. An alternative heavy 12 tonne warhead could be boosted to a 1000 km range. Barmin's GKB Spetsmash would provide the V-2-like mobile launcher.
So much new technology was involved that it was deemed necessary to build an R-3A intermediate experimental rocket, based on the R-2. This would be flown to test new construction methods, guidance systems, and high energy propellants. The R-3A would have a 900 to 1000 km range with a payload of 1530 kg; an unfuelled mass of 4100 kg; 20,500 kg of propellants; and a lift-off thrust of 40 tonnes. The R-3A could also serve as a prototype for a more modest IRBM.
The draft project was completed by Korolev in June 1949. In November 1949 the project plan was submitted to the NTS (Scientific-Technical Soviet) of NII-88 for review. The NTS met in plenary session on 7 December 1949 and subjected the proposal to withering criticism.
Isayev found extensive problems with Glushko's engine design. The huge increase in thrust, performance, and use of new propellants seemed a leap too far. But Korolev insisted that Polyarniy's design, using older technology, could not meet the requirements. In general the Soviet preferred Groettrup's G-4/R-14 design to the same requirement. This assumed fewer technical advances in engine design but greater improvements in mass fraction reduction:
|Parameter||Korolev R-3||Groettrup G-4/R-14|
|Payload to 3000 km||3,000 kg||3,400 kg|
|Lift-off mass||71,000 kg||70,000 kg|
|Burn-out mass||8,480 kg||7,100 kg|
|Burn-out velocity||4,700 m/s||4,500 m/s|
|Specific impulse-vacuum||288 sec||249 sec|
|Specific impulse-sea level||240 sec||234 sec|
After heated discussion, the Soviet approved further development of technology for the R-3, but not the missile itself. This work was to go forward on several fronts:
Work proceeded on the R-3 themes with significant German input, although they were not allowed to know how the work was going. Detailed technical questions were continued throughout 1950-1951, coming almost daily by March 1951. Meanwhile Glushko was unable to overcome mixing chamber instability in his 19-burner RD-110 engine concept. Further development of both the Glushko and Polyarniy engines was discontinued in 1951.
Work on the R-3A continued - another period of intense questioning of the Germans came in June 1952, when it seemed to them that a test flight of the R-3A was imminent. But in the end, the decision had actually been made to proceed directly to the R-7 ICBM. During development the range of the R-3A had settled on 935 km with only a 500 kg payload. It was cancelled in October 1951 without ever flying, with the technology being applied to further R-5 and R-11 development. The R-3 was completely cancelled, and a Soviet 3000-km IRBM did not appear until Yangel's R-14 entered service in 1962.
Payload: 5,000 kg. to a: 3000 km trajectory. Liftoff Thrust: 168,000 kgf. Total Mass: 65,000 kg. Core Diameter: 2.8 m. Total Length: 33.0 m.
In overnight roundup, 20,000 Germans transported to USSR to transfer technology on aerospace and other technical fields.
Decree 'On work on the R-1 and R-2 missiles' was issued. To accomplish putting the R-1 into production the resources of 13 research institutes and 35 factories were tapped. Glushko was tasked with producing the RD-100 copy of the V-2 engine. R-1 stand tests began the same day the decree was issued (Prototypes had already begun factory tests at the end of 1947). The decree also set forth design goals for the R-3.The specification was an order of magnitude leap from the other vehicles - to deliver a 3 tonne atomic bomb to any point in Europe from Soviet territory - a required range of 3000 km.
In selecting a final R-3 design, Korolev's preferred approach was a conventional single-stage design. This was down-selected within the bureau and seems to have borrowed a lot from contemporary classified US orbital rocket designs.
The NTS (Scientific-Technical Soviet) of NII-88 met in plenary session and subjected Korolev's proposal to withering criticism. The G-4 was found to be superior. After heated discussion, the Soviet approved further development of technology for the R-3, but not the missile itself. The decisions were: an R-3A technology demonstrator would be built and flown under Project N-1 (probably to prove G-4 concepts). Under Project N-2 both the RD-110 and D-2 engines would proceed into development test in order to prove Lox/Kerosene propellant technology. Packet rocket and lightweight structure research for use in an ICBM would continue under project N-3 / T-1. Winged intercontinental cruise missile studies would continue under project N-3 / T-2. Neither the G-4 or R-3 ended up in production, but the design concepts of the G-4 led directly to Korolev's R-7 ICBM (essentially a cluster of G-4's or R-3A's) and the N1 superbooster. Work on the G-4 continued through 1952.
The R-3 3000 km range missile and R-3A subscale technology demonstrator were cancelled. As a replacement work was to start on the R-5 and R-11. The missiles originated as Theme N-2 of the R-3 project. This was an alternate approach to delivering nuclear warheads on West European targets - road-mobile or sub-launched missiles of shorter range with lighter warheads that could be launched from forward areas and reach enemy targets.