»Rajnath Singh Inaugurates India's 1st Hypersonic Wind Tunnel Facility. Here's What it Means for Us 2-MIN READ Rajnath Singh Inaugurates India's 1st Hypersonic Wind Tunnel Facility. Here's What it Means for Us Rajnath Singh at the DRDO facility. (Image credits: Twitter) After America and Russia, India is the third country to have such a large facility in terms of size and operating capability, the defence ministry said. FOLLOW US ON: Defence Minister Rajnath Singh on Saturday inaugurated the advanced Hypersonic Wind Tunnel (HWT) test facility here, making India the third country after the US and Russia to have such a facility. The state-of-the-art HWT Test facility is "pressure vacuum driven enclosed free jet facility having nozzle exit diameter of 1 metre and will simulate Mach No 5 to 12 (Mach represents the multiplication factor to the speed of sound)", a defence release said.