In the early 1950s it was evident that the forthcoming
thermonuclear weapons would need
strategic delivery systems of a new kind. Until
the ICBM (intercontinental ballistic missile)
was perfected the only answer appeared to
be a supersonic bomber. After much planning,
Tsybin went to the Kremlin on 4th March
1954 and outlined his proposal for a Reaktivnyi
Samolyot (jet aeroplane). The detailed
and costed Preliminary Project was issued on
31st January 1956, with a supplementary submission
of a reconnaissance version called
2RS. Korolyov's rapid progress with the R-7
ICBM (launched 15th May 1957 and flown to
its design range on 21st August 1957) caused
the RS to be abandoned. All effort was transferred
to the 2RS reconnaissance aircraft.
The RS had an aerodynamically brilliant configuration, precisely repeated in the British Avro 730 which was timed over a year later. The wing was placed well back on the long circular-section fuselage and had a symmetric section with a thickness/chord ratio of 2.5 to 3.5 per cent. It had extremely low aspect ratio (0.94) and was sharply tapered on both edges. Large-chord flaps were provided inboard of conventional ailerons, other flight controls comprising canard foreplanes and a rudder, all surfaces being fully powered. The cockpit housed a pilot in a pressure suit, seated in an ejection-seat under a canopy linked to the tail by a spine housing pipes and controls. The RS was to be carried to a height of 9km (29,528ft) under a Tu-95N. After release it was to accelerate to supersonic speed (design figure 3,000km/h) on the thrust of two jettisoned rocket motors. The pilot was then to start the two propulsion engines, mounted on the wingtips. These were RD-013 ramjets, designed by Bondaryuk's team at OKB-670. Each had a fixed-geometry multi-shock inlet and convergent/divergent nozzle matched to the cruise Mach number of 2.8. Internal diameter and length were respectively 650mm (2ft IHin) and 5.5m (18ft 1/2in). The 1955 project had 16.5 tonnes of fuel, or nearly 3.5 times the 4.8-t empty weight, but by 1956 the latter had grown and fuel weight had in consequence been reduced. The military load was to be a 244N thermonuclear bomb weighing 1,100kg (2,4251b). The only surviving drawing shows this carried by a tailless-delta missile towed to the target area attached behind the RS fuselage (see below). Data for this vehicle are not known.
Outstandingly advanced for its day, had this vehicle been carried through resolutely it would have presented 'The West' with a serious defence problem.
As noted previously, the 2RS was launched as a project in January 1956. It was to be a minimum-change derivative of the RS, carried to high altitude under the Tu-95N and subsequently powered by two RD-013 ramjets. However, it was decided that such an aircraft would be operationally cumbersome and inflexible, and that, despite a very substantial reduction in operational radius, it would be preferable to switch to conventional afterburning turbojets and take off from the ground. The revised project was called RSR (described later). The Ministry gave this the go-ahead on 31st August 1956, but work on the 2RS continued until is was terminated in early 1957. As it was no longer needed, Tupolev then stopped the rebuild of the Tu- 95N carrier at Factory No 18 at Kuibyshev.
The 2RS would have differed from the RS principally in having the canard foreplanes replaced by slab tailplanes. Behind these was installed a braking parachute. Provision was made for large reconnaissance cameras in the fuselage ahead of the wing. Surviving drawings (below) also show provision for a 244N thermonuclear weapon, this time as a free-fall bomb recessed under the fuselage further aft. Carrying this would have moved the main landing gear unacceptably close to the tail.
Though there was much to be said for air launch, the basic concept looked increasingly unattractive.
|Function||strategic delivery vehicle||strategic reconnaissance|
|Dimensions & Weight|
|Wing Span (over engine centrelines), m||9||9|
|Wing Area, m2||64||64|
|Overall height, m||3,2||3,2|
|Take-off weight, kg||21160||20800|
|Empty weight, kg||5200||9030|
|Fuel weight, kg||15600|
|Engines||2 ramjet RD-013|
|Speed, km/h (M=)||max||3000 (2,82)||2700 (2,54)|
|Flight altitude, m||28000||2700|
|Landing run, m||1100|
|Bombs||1 244N thermonuclear||-|
References and Credits: