DRDO is developing the Agni-VI, a road mobile, containerized strategic missile with a range of 6,000 km that would be capable of carrying between 4 to 6 independently targeted warheads.
The number of warheads carried by the 20m long, 2m diameter and 65-70 ton would depend on the types of warhead deployed.
Like the Agni-V - which weighs 50 tons, is 17.5 m long and 2 m in diameter - the Agni-VI will have three solid propellant stages. Unlike the Agni-V, all three stages will be made using composites. (On Agni-V, the first stage is metallic, the second and third stages, composite)
The government has yet to sanction development of the missile, but DRDO has developed all the enabling technologies, finalized the design of the missile and started engineering its components.
DRDO scientists revealed the progress made on the missile and its characteristics in Bengaluru before the start of Aero India 2013. [via The Hindu]
"We have started working on the multiple independently targetable re-entry vehicles [MIRV] version [Agni-VI]. It will carry four or six warheads depending upon their weight,” DRDO missile technologists said. “The constraint is the vehicle’s mass.”
"Agni-VI will be a massive vehicle," the technologists said.
It was too early to say when its first launch would take place.
Speaking to the Business Standard in May 2013, DRDO missile chief Avinash Chander said, "Our ballistic missiles must be compact and road mobile, even the Agni-6 with its heavy payload. We will do this by building the first stage with composites, fitting the Agni-6 with India’s first composite 40-ton rocket motor. This is a technical challenge but we have good capability in lightweight composites."
Emphasizing the need for the missile to be compact, Chander added, "It must be carried on a standard size trailer that can move from one part of the country to another, turn on our roads, cross our bridges and climb our heights. As the payload weight increases, we will require more advanced technologies to keep the missile’s length constant."
Media speculation that DRDO is working on the Agni-VI, a 6,000 km missile with MIRV warheads, capable of canister based storage and launch from above ground or below sea started following the publication of a news item in the May 2011 newsletter of DRDO announcing the appointment of Shri Avinash Chander as Chief Controller R&D (Missiles and Strategic Systems).
Detailing Chander's recent achievement, the newsletter report added:
"He is an eminent scientist in the field of Missiles and is the Chief Designer of Long-range missile system, with specific contribution in Agni program management, mission design, guidance, navigation, simulation and terminal guidance. He has unique achievement of delivering and deploying three long-range Agni missile weapon systems viz, A1, A2 and A3.
Presently, he is leading three major system developments; A2p, a technologically challenging state-of-the-art system; a 5,000 km canister-launched A5 system; and a 6000 km A6 system with multiple warheads (MIRV) capable of launching both from the ground and underwater."
The A2p missile referred to in the newsletter is probably the Agni-II Prime which was renamed Agni-IV after its first successful test. .
In the past, on several occasions, DRDO chief VK Saraswat has stated DRDO's intent to develop a MIRVed version of Agni-V. It is also possible that Agni-V range could be improved after it is successfully tested.
However, it is unlikely that the A6 system referenced in the newsletter is an improved Agni-V because the Agni-V, which is 17.2m long and 2m in diameter, is probably too long to fit into a Arihant class submarine missile tube.
In the past, it has also been reported that DRDO is working on a followup to the 3,500 km K-4 SLBM with longer range.
It is logical for DRDO to develop a cold launched, 6,000 km range missile that is around 12m long and can fit into a 2.4 m container (Missile tubes on Arihant are reportedly 2.4 m diameter). The missile could be land based in a canister, or sea based in a submarine silo.
A day after the successful maiden test of the Agni-V missile on April 19, 2012 during a press conference in New Delhi DRDO Chief VK Saraswat clarified that the future Agni missile has not been named 'Agni-VI' as has been speculated in a section of the media.
However, the DRDO Chief indicated that India's missile development program will continue.
"Our missile development program is based on today's, current and evolving threats. Evolving threats will continue to drive our future needs for platforms and weapons," he said. [via DNA]