In a major technology leap, Indian defence scientists are ready to go ahead with the first full test flight of its indigenously developed air to air beyond visual range missile, ASTRA.

 The test-flight from an IAF Sukhoi fighter aircraft could be undertaken "anytime in the next 45 days", top DRDO officials said.

 A successful test flight of ASTRA will plunge India into a select group of nations to have such a technology. Only US, France [Images], Russia [Images] and China have so far produced such advance missiles, which enables fighter pilots to lock-on and shoot down enemy aircraft almost 90-120 km away.

Describing ASTRA as a futuristic missile, DRDO scientists said the weapon will intercept the target at mach 1.2 to 1.4 speed. The missile has already been tested on ground to prove its avionics, guidance and other sub-systems including propulsion.

Any success with air to air ASTRA missile will come as another milestone in defence research and cap recent strings of success the DRDO scientists have had in building at producing for the country -- short to medium range � surface to surface missile system capable of delivering nuclear war

heads at long distances. The test firing of the ASTRA missile may coincide  with the second test firing of country's anti-missile missile, which is also due by September this year.

The defence scientists are also near breakthrough in test firing the country's first underwater launch ballistic missile, Sagarika.

Sagarika has already been test-fired from a pontoon, but now DRDO is planning a full-fledged test of the missile from a sub-marine and for this purpose may use the services of a Russian Amur class sub-marine.

Planned to arm the country's indigenous Light Combat Aircraft, Tejas, ASTRA after user trail by IAF may now be initially integrated with the SU-30 MKI and later with LCA.

Though DRDO scientist refused to give out the range of the ASTRA missile, sources said for extreme high altitude interdiction the initial series of ASTRA missile will have 90-110 km skill range.

But at lower altitudes of up to 30,000 ft the missile will have a range of 44 kms and those launched at sea level of up to 30 km.

DRDO officials said ASTRA could also arm the IAF's frontline aircraft MIG-29 and Mirage 2000 which are to go in for mid-life upgradation this year.