With the La-250 being plagued by development issues, and the MiG-21 – designed around exactly the same planform – proving too light and too short-ranged for the task, eventually it fell to the Sukhoi Su-9 to become the most potent high-speed/high-altitude interceptor of the PVO in the early 1960s. Its prototypes set several new records in sustained speed and altitude, while series production was initiated in 1959. In operations, the Su-9 proved capable of reaching up to Mach 2 at 20,000 metres (66,000ft) while armed with RS-2U/K-5 missiles. Unsurprisingly, one was involved in intercepting Francis Gary Powers’ U-2 on 1 May 1960, but because the jet was unarmed, its pilot, Captain Igor Mentyukov, was ordered to attempt ramming. Mentyukov missed and then ran out of fuel but claimed that it was his slipstream that caused the U-2 to break apart. The Su-9 continued serving with the PVO through the 1960s, and became involved in numerous other intercept attempts, but is not known to have ever scored any aerial victories , bar a few aerostats. This example served with the 393th Guards Interceptor Aviation Regiment of the Baku Air Defence District. (Artwork by Tom Cooper)