The Tu-121 intermediate range cruise missile was developed on order of a decree of 23 September 1957. The decree described a 3,000 to 4,000 km range missile with trials to begin by the end 1958. The astronavigation system for the missile was derived from that developed for Burya, built by NII-1 MAP under V G Chachikiyan. The missile was land mobile, carried on an ST-10 mobile launch trailer, with the wings removed for transport. Following launch the astronavigation system would engage five minutes after launch. The missile would already have covered 200 to 300 km of range before reaching its cruise altitude. The missile would pitch over at the target into a dive at a 55 degree angle. The thermonuclear warhead would detonate at 2 km altitude. In the event of any deviation from the planned course, an internal destruct system would destroy the missile.
Five prototypes were built; the first fuselage was completed in June 1958 and the first prototype was completed in late 1958 at Yauz. Launcher tests were conducted in the winter of 1958-1959 at the NIIAS test centre near Moscow. The first launch with an incomplete system was conducted on 31 December 1958 (thereby fulfilling the decree schedule). In 1959 the first full prototype was delivered to Vladimirovka, followed by the first unsuccessful launch attempt on 25 August 1959. A total of four flight tests had been completed when a decree of February 1960 cancelled all further work on winged long-range missiles. A total of seven cruise stages were completed at the time the project was cancelled. However the Tu-121 was elaborated into the Tu-133 intercontinental cruise missile design, which in turn was the basis for the DRB-1 Yastreb trisonic target drone, which did reach production.
The Tu-121 would have had a range of 3880-4000 km, cruising at 2775 km/hr at an altitude of 19.9-24.1 km. It was to have been equipped with a '205' nuclear weapon built by NII-1011, with a total mass of 3 tonnes. Its AP-85 autopilot used the Zemlya-AI astro-navigation system. The RAT-52 launch stage used two PRD-52 solid rockets for zero-length boost from the launch trailer.
Guidance contractor: NII-1 MAP. Standard warhead: 3,000 kg (6,600 lb). Maximum range: 3,880 km (2,410 mi). Number Standard Warheads: 1. Standard warhead: 205. Boost Propulsion: RAT-52 Solid rocket. Cruise Thrust: 98.000 kN (22,031 lbf). Cruise Thrust: 10,000 kgf. Cruise engine:KR-15-300. Maximum speed: 2,775 kph (1,724 mph). Total Number Built: 7.
AKA: S; 121.
Status: Cancelled 1960.
Gross mass: 32,600 kg (71,800 lb).
Payload: 3,000 kg (6,600 lb).
Height: 24.77 m (81.26 ft).
Diameter: 1.70 m (5.50 ft).
Span: 8.40 m (27.50 ft).
Thrust: 790.00 kN (177,590 lbf).
Apogee: 24 km (15 mi).