Two shorter-range missiles (the RSA-1 and RSA-2) were intended for use on Cuban or Warsaw Pact troop concentrations should a massed attack be made from an adjacent country. The RSA-4 ICBM was also in long-term development, possibly to deter the United States or Soviet Union from sponsoring such an attack in the first place.
The original intended payload for the missiles was said to be the uranium gun-type atomic bombs developed in South Africa between 1971 and 1989. Seven of these weapons were built, each with a mass of about one tonne, a diameter of 65 centimetres and a length of 1.8 meters. Each device contained 55 kilograms of highly enriched uranium, producing a fission yield of 10-18 kilotons. Five of the weapons were configured as air-launched bombs, but were said to be adaptable to missile launch. It was planned during the 1990's to lighten and modernise these warheads, and use tritium-boosting to increase the yield to 100 Kt. A missile using the original devices would have to be provided with a heat shield, implying a total warhead mass of around 1500 kg. This would not have permitted the RSA-4 to reach intercontinental range. Presumably the boosted, modernised warheads, that were to have been completed by 2000, would have been under 700 kg and allowed the missile to reach New York or Moscow.
Substantial facilities for assembly, test, and launch of the rockets were built at the Overberg Test Range at the tip of Africa. Overberg was also used for Israeli Jericho-2 test flights.
As a cover for and supplement to the missile development, the R5b indigenous space programme was funded. This would use the RSA-3 and RSA-4 launchers. Four South African space rockets were built. Three were launched into suborbital trajectories in the late 1980's in support of development of the RSA-3 launched Greensat Orbital Management System (for commercial satellite applications of vehicle tracking and regional planning). The range was also used for aerospace and system testing for British, Swedish and Czech programmes.
Following the decision in 1989 to cancel the nuclear weapons program, the missile programs were allowed to continue until 1992, when military funding ended and South Africa officially ended its missile collaboration with Israel. All ballistic missile work was stopped by mid-1993. In order to join the Missile Technology Control Regime the government had to allow American supervision of the destruction of key facilities applicable to both the long range missile and the space launch programmes. The RSA-3 and RSA-4 space launchers were therefore cancelled in 1994.
Prime Contractor Houwteq had to dismantle its existing RSA rocket components, and retrieve and sequester technical data from its subcontractors. Propellant manufacturer Somchem eliminated the RSA solid propellants and rocket casings that remained in stock. Denel filled in its large engine casting pits at Somerset West and demolished its large-scale X-ray inspection equipment. The Hangklip static motor test facility at Rooi Els was converted to a nature reserve. The Overberg Test Range was allowed to remain for use by 'potential foreign partners'. Following these measures, South Africa joined the Missile Technology Control Regime in September 1995.
Houwteq's staff at Overberg grew to a peak of 500 in 1992, before the cancellations began. By 1997 the staff was reduced to 28. Houwteq's Ian Farr continued to market the Overberg facility for commercial launchers until at least 1997. Nothing came of these efforts, and it seems that the book was closed on further indigenous African space activities.
Since much remains undisclosed about the Israeli Jericho missiles and Shavit - Next space launchers, the material on the South African rockets provides some insights into Israeli programmes. The RSA-2 clearly corresponds closely to the Jericho-2, and the RSA-3 to the Shavit launcher. It is interesting that there has been no mention of an Israeli counterpart to the Peacekeeper-class first stage motor of the RSA-4. This may represent a 'reserve' Israeli capability to upgrade the Jericho-2 to ICBM range that has never been made public. However there have been reports of Israeli development of a MIRV capability for its missiles. The post-boost warhead dispenser for such a capability could correspond to the RSA-4 fourth stage.