a missile inside containing a single warhead, such as the RT-2PM Topol, emitted a different pattern of fast neutrons than did one with a missile having three warheads, such as the RSD-10. Provisions of the SALT II agreement prohibited the deployment of more than one new missile (which became RT-23UTTh), it was officially declared by the Soviet Union that the RT-2PM Topol was developed to upgrade the silo based RT-2. The US government disputed this view, contending that the missile was clearly more than 5% larger and had twice the throw-weight as the RT-2 and therefore constituted a new missile system. Marshal Nikolai Ogarkov, Soviet Chief of General Staff cancelled the September 1, 1983 test flight of the RT-2PM Topol which was to be launched from Plesetsk (the launch site in northwest Russia used for test firing of solid fuel propellant ICBMs)- 24 minutes later to land in the Klyuchi target area on the Kamchatka Peninsula. The night of the scheduled launch was the night that Korean Air Lines Flight 007 was shot down after accidentally intruding Soviet airspace over Kamchatka. An RT-2PM Topol with two MIRVs may have been tested in 1991, and the missile was tested at least once with four MIRV warheads, but there has apparently been no further development of a multiple warhead version. This became a point of contention during the conclusion of the 1991 START negotiations, at which time the US pressed for a definition of "downloading" (removing warheads from missiles) that would complicate any Soviet attempt suddenly to deploy multiple warheads on the RT-2PM Topol. Russia plans to reequip approximately 400 silos where obsolete UR-100, RT-2 and MR-UR-100 missiles are located. Under the START II Treaty, which never had and most likely will never have a binding effect, Russia would have been able to place 90 single-warhead solid fuel missiles in reequipped R-36 silos. In order to guard against a break-out scenario involving the rapid reconversion of R-36 silos on-site inspection became a very important aspect of START II verification. Post-Soviet period The breakup of the Soviet Union had a significant impact on the Topol program. The dispersed manufacturing of ICBM components seriously complicated researching and building new missile systems. For example, the Minsk Wheeled Truck-Tractor Manufacturing Plant in Belarus manufactured the missiles' transporter launchers, and some 90% of the components of the guidance system were manufactured in Ukraine. In Belarus, as of