The Taran was a variant of the basic UR-100 ICBM vehicle capable of shooting down enemy ICBM's within a range of 2000 km. The basic UR-100 guidance system by NIIAP/Pilyugin was designed to work with any UR-100 variant and the vehicle could be converted from one configuration to another within 24 hours. However for use as an ABM the launch complex needed some additional equipment. Chelomei cooperated with G B Kisunko at OKB-30 to develop an energetically manoeuvring control system for the UR-100, and a command point for guidance of the system against incoming manoeuvring re-entry vehicles. Work on the Taran ABM version began in 1962. The concept was ingenious, in that offensive missiles could be turned into defensive missiles in response to changes in enemy posture. In this role the missile carried a 10 megaton warhead.
Upon detection of enemy launches, a UR-100 would be launched toward the trajectory of an incoming re-entry vehicle. The new TsSO-S multi-target radar, to be located 500 km from Moscow at an existing missile early warning centre in the Leningrad region, would be the only new element required for the Taran system. The TsSO-S would track enemy re-entry vehicles and then calculate the intercept point and time for each warhead. The station would be interlinked with early warning radar stations RO-1 in Murmansk and RO-2 in Riga. Taran would be used together with the A-350 missile being developed for the defence of Moscow as part of a layered defence. Taran could defend the most heavily populated area of the Soviet Union, from Leningrad to Moscow, from a single basing area.
Development of an advanced project for the Taran was ordered by a decree of 3 May 1963. Mintsa was put in charge of the advanced project, with assistance from Chelomei. However other elements of the Soviet technical leadership did not share Chelomei's enthusiasm for the scheme. The Keldysh Institute calculated that to destroy 100 incoming Minuteman ICBMs, 200 UR-100s would be required. This seemed excessive both from a cost-benefit point of view and the immense megatonnage that would be exploded in space over Soviet territory. Therefore Keldysh persuaded Khruschev to cancel Taran in 1964. The Achilles heel for the whole concept was the single TsSO-S tracking station, which was required for the whole system to work.
Taran was resurrected in 1980's and pitched to Gorbachev on a visit to Baikonur. The chief designers were scrambling to identify quick responses to the American Star Wars space defence system. The negative reaction of the Soviet leadership was the same as in 1964.
Maximum range: 2,000 km (1,200 mi). Number Standard Warheads: 1. Warhead yield: 10,000 KT. Boost Propulsion: Storable liquid rocket, N2O4/UDMH. Cruise engine: 8D423.
AKA: 8K84; 15P784; 15A10.
Status: Cancelled 1964.
Gross mass: 41,410 kg (91,290 lb).
Height: 16.93 m (55.53 ft).
Diameter: 2.00 m (6.50 ft).
Span: 2.00 m (6.50 ft).
Thrust: 785.00 kN (176,475 lbf).