ballistic missile next month.
"Agni-III, a 16.7-metre tall missile with a lift-off weight of 50 tonnes, should be tested within a month, towards end-July. This will be another step towards inducting it into the armed forces,'' said top defence sources on Friday.
Once fully-ready by 2011-2012, Agni-III will provide India with the capability to strike deep into China, with cities like Shanghai and Beijing well within its potent reach.
India, incidentally, is also working on the 5,000-km-range Agni-V missile, which will have near-ICBM (intercontinental ballistic missile) capabilities, but it will be ready for its first test only by late-2010.
Asked about the Agni-V on Friday, defence minister A K Antony only said the government was taking "all steps'' to build "whatever capabilities'' were needed "as per changing threat perceptions'' to protect national security.
Both Agni-III and Agni-V are primarily designed to bolster India's "active credible deterrence posture'' against China, especially since it has a clear-cut "no-first use'' nuclear doctrine.
China's expanding nuclear and missile arsenal, of course, has even the US worried. The Chinese DF-31A ICBM, with a strike range of 11,270 km, for instance, can target any location in the continental US.
India's missile programme is rudimentary by these standards, and even lags behind Pakistan in certain aspects. In fact, only the Prithvi (150-350 km) and Agni-I (700-km) missiles, primarily meant for Pakistan, can be said to be fully operational in the armed forces till now.
The tri-Service Strategic Forces Command is still engaged in conducting "training user-trials'' of the 2,000-km Agni-II. The first such Agni-II trial last month "failed to meet the laid-down flight parameters'', say sources.
But defence scientists say they are not deterred by a flop or two. The first test of the rail-mobile Agni-III in July 2006 had flopped miserably, spurring them to ensure the second one in April 2007 and the third one in May 2008 were successful.
As for India's most ambitious missile till now, the Agni-V, the scientists are incorporating a third composite stage in the two-stage Agni-III, along with some advanced technologies like ring laser gyroscope and accelerator for navigation and guidance.
They want the solid-fuelled Agni-V, for which the government has sanctioned around Rs 2,500 crore, to be a canister-launch missile system to ensure it has the requisite operational flexibility to be fired from any part of the country.