National
Advantages of the Agni variant
By N. Gopal Raj
THIRUVANANTHAPURAM, JAN. 26. The short-range Agni missile tested on Friday appears to consist of just the first stage of the earlier Agni versions and has distinct technological advantages.
The first Agni missiles, touted as ``technology demonstrators'', used solid propellant-based first stage of the SLV-3, India's first launch vehicle. These missiles, the first of which was launched in 1989, had a second stage with a liquid propellant engine which has also been used to propel the single- stage Prithvi missile.
The all-solid two-stage Agni-II, where a new solid- propellant second stage replaced the old liquid propellant one, was first test-fired in April 1999 and then again last January. The short-range Agni seems to have done away with the second stage altogether and become a single-stage solid propellant missile.
All-solid missiles such as the Agni-II and the new short-range Agni can be fired at short notice. Whereas, the liquid-fuelled Prithvi missile is transported empty and it takes time to fill its propellant tanks before its launch.
Liquid engines, however, can be shut off when the requisite velocity is reached. For precise targeting, it is essential that a missile imparts just the right velocity to the warhead.
The Agni-II carried a ``velocity-trimming package'' to compensate for the slight performance variations inherent in solid motors. The package in the Agni-II is said to have consisted of liquid-fuelled thrusters (which are small rocket engines). The new short-range Agni is likely to have retained this velocity trimming package.
Since the principal difference between the Agni-II and the short-range Agni is the absence of the second stage in the latter, there would be many systems in common. This would greatly simplify production, maintenance, and ground handling.
From the time India successfully launched the SLV-3 - an all-solid four-stage rocket in 1980 - it has had the capability to build fully solid ballistic missiles such as the Agni-II and the short-range Agni.
However, it is not clear why it chose to build liquid fuel-based missiles such as the Prithvi and the early Agni version, when the Integrated Guided Missile Development Programme was started in 1983 itself.
Send this article to Friends by
E-Mail
National
|
