Nov. 27: India unveiled its own ballistic missile defence programme this morning, firing a mystery interceptor over the Bay of Bengal that struck a Prithvi surface-to-surface missile 50 km above Earth off the Orissa coast.

The target missile was launched from a mobile launcher at the integrated test range in Chandipur at 10.24 am. A minute later, the interceptor was fired from another mobile launcher on Wheeler Island, 72 km from Chandipur.

The “exoatmospheric intercept system”, which means it is capable of striking missiles outside the Earth’s atmosphere, introduces a new element to the missile race in the subcontinent.

Three missiles have been tested by India and Pakistan in the last fortnight. Pakistan tested the Ghauri (Hatf V) on November 16. Three days later, India tested the Prithvi II from Chandipur.

The last firing of the Prithvi was most certainly a build-up to today’s test because it was described as part of “air-defence exercises”. The Prithvi is not an air defence missile but was modified for the test today as the target to be shot down by the interceptor.

“The country today achieved a significant milestone in missile defence system,” a defence ministry statement said.

The “exoatmospheric” missile’s range was simulated because of limitations of space, said a source at the Defence Research and Development Organisation (DRDO).

India has been looking to acquire tactical missile defence capability and the defence establishment is being briefed by the US on the Patriot III, by Israel on the Arrow and by Russia on the SV-300.

The mystery interceptor has not been named yet, the DRDO chief controller (research and development), V.K. Saraswat, said. Described as “10 to 12 metres long”, it was probably made at the Defence Research and Development Laboratory, a DRDO establishment in Hyderabad.

The interceptor has been in the works for at least three years. This morning’s was the first test-firing of an interceptor by India. “It is a completely indigenous system,” said Saraswat, who was leading the team of scientists on Wheeler Island.

An interceptor is by definition capable of flying faster than an intruding missile. Asked for the speed at the time of impact, DRDO sources said it was “high supersonic”. The sources said the two missiles had a combined flight duration of six minutes before they dropped into the sea.