The anti-satellite test apparently conducted by China on January 12, 2007 immediately reminded everyone of the U.S. and Soviet cold-war ASAT programs. Some Russian commentators even suggested that the system tested by China is just a replica of the Soviet “IS” system. Well, not quite.

The “IS” system (“IS” stands for “istrebitel sputnikov” – “satellite fighter”) was developed back in the 1960s. The system, which included an automated launch system in Baykonur, space-surveillance radars, and the command center in Noginsk near Moscow, was accepted for service in 1968. The launcher used in the system, 11K69, was based on the orbital version of the R-36 (SS-9) missile. The interceptor carried an explosive warhead that would detonate within about ten meters of its target (50 meters appears to be the upper limit for miss distance, although it certainly depended on the warhead).

The “IS” system underwent several modernizations – the first upgrade, “IS-M”, was deployed in 1978. It could target satellites deployed in orbits with altitudes of 250-2200 km (from about 250-1000 km of the “IS” system) and inclinations of 50 to 130 degrees. Designers of the system estimated that it provided the probability of kill of about 70-80 percent.

As far as I understand, unlike the reported Chinese system, neither “IS” nor “IS-M” was a direct-accent system – before approaching the target an interceptor would have to get information about its own orbit from ground space-surveillance radars. This would normally require two revolutions, so the intercept process would take three to five hours. The Soviet Union conducted a few one-revolution intercept tests in 1976-1977, but then returned to the two-revolution scheme. In any event, an interceptor of the “IS” system would have to reach an orbit, even if for an incomplete revolution, while the Chinese missile appeared to fly along a ballistic trajectory directly toward the target.

The last test of the “IS-M” system took place on 18 June 1982, during a large-scale exercise of the Soviet strategic forces. In 1983, the Soviet Union announced a unilateral moratorium on all anti-satellite tests. The system nevertheless underwent another modernization. The new system, “IS-MU”, was reportedly given a capability to intercept maneuvering satellites. According to the plans of the late 1980s, the system was to be converted to 11K77 Zenith launchers by mid-1990s. These plans, however, were interrupted by the breakup of the Soviet Union. In 1993 the “IS-MU” system was withdrawn from service.

The “IS” program was not the only Soviet anti-satellite project. In response to the U.S. program to develop an aircraft-based ASAT, the Soviet Union launched a similar effort. The decision to begin development of a “Kontakt” system, which would include an interceptor launched from a MiG-31 aircraft, was approved by the Soviet government on 27 November 1984 (the United States conducted first test of its system earlier that year – on 21 January 1984 and 13 November 1984). The “Kontakt” system was developed by NPO Soyuz. The system was expected to provide the capability to launch up to 24 interceptors in the space of 36 hours to hit satellites in orbits with altitudes of 120-600 km. The upper range of intercept was to be extended to 1500 km during later modernizations of the system. Development of the "Kontakt" system, however, did not reach the stage of flight tests and was suspended even before the breakup of the Soviet Union.

The Soviet ASAT project that the reported Chinese system resembles most closely is “Naryad-V”. This project, developed in the Salyut Design Bureau, involved development of an interceptor that was to be deployed on existing silo-based intercontinental ballistic missiles (both R-36M/SS-18 and UR-100NUTTH/SS-19 were discussed, but the UR-10NUTTH was the primary candidate). A missile was to carry one or two interceptors that could target satellites in a wide range of orbits – with inclinations from 0 to 130 degrees and altitudes from 150 to 40,000 km. Intercept of spacecraft on high orbits would have taken up to seven hours, but LEO intercepts were expected to take from 30 minutes to 2.5 hours. It may have involved a direct-accent hit.

The “Naryad-V” system was in active development up to the end of the Soviet Union and the project may still exist. The first flight test of the “Naryad-V” spacecraft took place on 20 November 1990, in a suborbital flight of the Rockot launcher (which is a modified UR-100NUTTH/SS-19 missile). Another suborbital flight of Rockot was conducted on 20 December 1991, but it is not clear if it was a flight test of “Naryad-V”. The first orbital flight of a “Naryad-V” spacecraft (again launched by Rockot) was reported to take place on 26 December 1994. The spacecraft was declared as “Radio-ROSTO” satellite. It is quite possible that it was indeed a peaceful satellite built around the “Naryad-V” platform – the information on the program is quite scarce.

[UPDATE: I forgot to mention another ASAT project considered by the Soviet Union in the 1980s - a non-nuclear anti-satellite interceptor for the A-135 Moscow ABM system. The project, approved in 1985, was known as "Amulet".]

Eventually, the common problem of all ASAT systems is that they are quite useless – the best they can do is to take out few satellites, which any space-based system should be able to beat with having redundancy built in. The cold-war U.S. and Soviet programs were driven mostly by their respective military industries, not by any reasonable military considerations. So far China has been sane enough stay away from the expensive and useless cold-war type projects. It would be sad indeed if it decided to change this policy.