The two-stage DF-4 (CSS-3) limited-range ICBM was designed initially to hit the US base at Guam and later modified to increase its range to 4750 kms so as to be able to strike Moscow. The launcher is a DF-3 with an added upper stage designed to provide power for boosting a 2,200 kilogram 3-MT warhead over a range of 5,500-6,000 kilometers. The first tests of this system were conducted in November 1970. Deployment actually began in 1975-76. An estimated 30 DF-4s have been constructed for ballistic missile use. Two launch configurations exist for the CSS-3: a rollout-to-launch site and an elevate-to-launch silo. Many of the DF-4s are stored in tunnels under high mountains, and are launched immediately outside the mouth of the tunnel.
On DF-4 was based CZ-1, launch vehicle of first Chinesse satellite. First and second stages were adopted from the missile and third stage with solid rocket motor was added to obtain orbital velocity for the satellite.
