he Dong Feng 5 or DF-5 (also known as CSS-4) is a 3 stage Chinese intercontinental ballistic missile (ICBM). The DF-5 had its first flight in 1971 and was in operational service 10 years later. Initially the DF-5 ICBMs were stored in a horizontal position in tunnels under high mountains and were to be launched immediately outside the mouth of the tunnel. These missiles must be moved into the open and fueled prior to firing, with the fueling requiring from 30 minutes to two hours. The deployment of a pair of DF-5 ICBMs in silos in central China was completed in 1981. That portion of the DF-5 force that is deployed in silos can be maintained in a ready-to-fire status. In order to enhance the survivability of these missiles, China has constructed a large number of decoy silos which consist of shallow holes excavations with headworks that resemble operational silos.When the DF-5 was first tested in September 1971, it had a range of 10,000 to 12,000 km which allowed it to threaten the western portions of the United States. Beginning in 1983 the Chinese developed the improved DF-5A, with range increased to over 13,000 km and a more accurate guidance system. The DF-5A upgrade increased the throw-weight of the system from 3,000 kg to 3,200 kg.