Bangalore: India’s defence scientists on 24 September began testing a smaller version of its hypersonic aircraft, or an unmanned plane, which flies at nearly three times the speed of a fighter jet, at a test facilityin Russia.
The 1m rectangular-shaped craft is being tested to fly at Mach 6.5—or six-and-a-half times the speed of sound—in simulated conditions at a lab of the Central Aerohydrodynamics Institute on the outskirts of Moscow. It will help validate similar tests for aerodynamic stability done on a smaller scale for Mach 4, or nearly 5,000km per hour, and computer simulations done by scientists at the Defence Research and Development Laboratory (DRDL), the missile lab of India’s defence research agency in Hyderabad.
The National Aerospace Laboratories has a facility for tests of Mach 4 being used by both DRDL and the Indian Space Research Organisation (Isro), India’s space agency. DRDL has drawn plans for new test centres at its guarded facility for higher speeds.
Simultaneously, work has begun on building a 5.6-m technology demonstrator of the hypersonic aircraft, at SEC Industries Ltd, a Hyderabad defence systems builder. DRDL plans to test the demonstrator by end-2008.
The hypersonic plane, enclosed in a capsule, will be fired by an Agni missile booster to a height of around 32km, at which point the capsule will open to allow the aircraft to fly at Mach 6.5 for 20 seconds, said S. Panneerselvam, director of the hypersonic technology demonstrator vehicle project at DRDL, a unit of Defence Research and Development Organisation (DRDO).
While “2008 is a possibility, it (the timetable) could spill over,” said B.N. Raghunandan, chairman of the aerospace engineering department at the Indian Institute of Science.
DRDL will invest Rs120 crore for the two-technology demonstrators and a spare aircraft for the project, and is already working on a new hypersonic vehicle to fly for over 400 seconds. “It will take another four years for the new vehicle that will have an additional tank for the fuel,” said Panneerselvam.
Hypersonic aircraft have air breathing engines known as supersonic combustion ramjet, or Scramjet, which takes oxygen from the atmosphere and burns kerosene or liquid hydrogen to achieve speeds, several multiples that of conventional jets. Besides the engine, the aircraft needs material that can withstand high temperatures of more than to 1,400 Kelvin or 1,127 degrees Celsius, due to the heat generated flying high speeds.
The US, Russia, Japan and China are working on hypersonic technology that can help build high-speed cruise missiles or reconnaissance aircraft for military use. The technology could also be used to reduce time and costs of space travel.
Isro will test the air breathing or Scramjet engine next year for speeds of Mach 6 after firing from a two-stage sounding rocket into the atmosphere. In 2009, it will fly a demonstrator of a reusable launch vehicle using Scramjet propulsion that burns oxygen with on-board fuel such as liquid hydrogen. “The focus is to build technologies that will reduce the cost of sending a mission to space,” said G. Madhavan Nair, chairman of Isro.