Russian Hypersonic Missile Scientists Accused of Treason.

Three Russian academics who have worked on hypersonic missile technology face "very serious accusations" of treason, according to the Kremlin. The case has spread alarm through Russia's scientific community. Colleagues of the accused have published an open letter in their support, protesting their innocence and saying the prosecutions threatened to inflict grave damage on Russian science. President Vladimir Putin has boasted that Russia is the global leader in hypersonic missiles, capable of travelling at speeds of up to Mach 10 (12,250 kph) to evade enemy air defences.