The missiles were to be based on the RSA-3 and RSA-4 launchers that had already been built and tested for the South African space programme. According to Al J Venter, author of "How South Africa built six atom bombs", these missiles were incompatible with the available large South African nuclear warheads, he claims that the RSA series being designed for a 340 kg payload would suggest a warhead of some 200 kg, "well beyond SA's best efforts of the late 1980s." Venter's analysis is that the RSA series was intended to display a credible delivery system combined with a separate nuclear test in a final diplomatic appeal to the world powers in an emergency even though they were never intended to be used in a weaponized system together. Three rockets had already been launched into suborbital trajectories in the late 1980s in support of development of the RSA-3 launched Greensat Orbital Management System (for commercial satellite applications of vehicle tracking and regional planning). 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 all ballistic missile work was stopped by mid-1993. In order to join the Missile Technology Control Regime, the government had to allow U.S. supervision of the destruction of key facilities applicable to both the long range missile and the space launch programmes.