The Defence Research and Development Organisation and the Indian Navy, recently tested the ability of launching a ballistic missile from underwater using a pontoon.

The launch was said to be successful in that the scientists were able to calculate and experiment with the amount of thrust that would need to be generated to push the heavy missile out of the water given the drag exerted by the water on a body moving through its ambiance.

The depth at which the pontoon was placed under water was approximately that which a nuclear-powered submarine would need to be stationed if it is to retain the secrecy of its presence before the launch and be able to make a swift getaway after the missile has cleared the surface of the ocean waves.

The thrust is provided by a gas canister that separates as soon as the missile clears the water and its motors are automatically ignited to push the missile through its pre-determined trajectory to target through the atmosphere.

It is a delicate operation and many parameters, including the amount of pressure the water exerts on the launch tube and the amount of thrust-to-weight of missile would be required for a successful launch need to be determined in advance.

Nonetheless similar launches will need to be undertaken from a submerged submarine before the third (and most assured deterrent) becomes part of the triad necessary to ensure that no neighbor is able to take advantage of India.

How many such launches will need to be conducted will depend on how well the computer simulation studies contribute to the hastening of the process of testing the validity of the launch standard operating procedures.

A few tests will also have to be carried out from India’s nuclear submarine, the Arihant, to ensure that both the submarine and the sea-launched ballistic missile (SLBM) are in sync and can be operated as a weapon system in the eventuality of hostilities in our neighborhood.

Nuclear deterrence

It is the stealth characteristics of the launch platform (submarine) that creates the uncertainty that is so essentially a part of the concept of mutual assured destruction (MAD) in a nuclearised environment that will deter the enemy from being adventurous.

India has been at somewhat of a disadvantage in its attempt to create its sea-based nuclear deterrent in that there has been a disjoint between the submarine and the missile in terms of specifications and size.

The missiles that were needed with a certain urgency became operational depending on the range requirement. Beginning with the short-range Prithvi missiles the Integrated Guided Missile Development Program has only recently delivered an inter-continental ballistic missile capable of hitting targets at more than 5000 km.

The girth of all the surface-to-surface missiles under this program was not constrained by a pre-determined requirement of being fitted to a submarine as well.

Although the Advanced Technology Vehicle (nuclear submarine) project was started at around the same time, the need to be ready to counter Pakistan’s clandestine nuclear weapons program ensured that whatever was seen to be functional was inducted even as the warhead was kept in mothballs.

It was finally tested when Indian intelligence came to the conclusion that US expert Leonard Spector’s prophecy that Pakistan’s “Bomb in the basement” program was just “two screwdriver turns away” from fruition was about to come true.

Just how close was the race could be seen in the swift manner Pakistan responded to India’s series of test at Pokharan in May 1998?

Indian assessment of the China-Pak nuclear collusion was on the spot at every turn and twist of the sordid nexus. Fortunately for the nation both the political leadership and the scientists were in complete agreement about what is required and how it is to be achieved.

If the length and diameter of the delivery vehicle created the desired range and brought Pakistan’s vital areas and vital points within reach that was the immediate requirement. If the range requirement was fulfilled it did not matter how broad and long the missile was.

Thus, the same logic guided the creation of the first set of Prithvi missiles to be charged with the more volatile liquid fuel instead of holding the program till the more stable solid fuel was available. India needed to show Pakistan that a nuke was available to prevent it from making a horrible mistake.  

Hence a great deal of re-engineering was required to be done to fit a missile into the vertical launch tubes of a submarine. The Arihant nuclear submarine is the first of its kind that has been manufactured in India.

From it will be learned many lessons for application in future nuclear submarines in which the height, the diameter and weight of the missile can be designed for greater range when fired from a submarine the dimensions of which will be governed by that one requirement.

The point would be that all future generations of submarine launched ballistic/cruise missiles would not consume the time that it has taken to bring the Arihant Advanced Technology Vehicle to fruition.

Where does India stand at the moment with regard to the third leg of the triad of nuclear weapons? A Naval Chief has said that once the Arihant is operational the triad would be in place.

The Sagarika alias K-15 missile with a range of 750 km was the one that was tested from a pontoon launch in the Bay of Bengal in late January and with it, the developmental phase of the missile was completed and it is now ready for operational deployment from any submarine in which it fits.

Future programs

The last test at the end of January this year was conducted over its full range of 750 km carrying a 1000 kg warhead. It can hit 1900 km carrying a 180 kg nuclear warhead. Its weight is less than 10 tons, length ten meters and diameter 0.74 meters. It can be launched from any submarine that has similar specifications of launch tubes.

In case the tubes are larger in diameter it is possible to pack it with a sabot or sleeve so that there is a snug fit and the missile can be gas-launched without the gas escaping from the sides and thereby reducing the thrust.

Another missile capable of being submarine-launched is part of what is also known as the “K” (for A P J Abdul Kalam, missile-man and former President of India) family. The K-4/5 will have a range of 3500km. Another submarine-launched missile under preparation is the Nirbhay sub-sonic cruise missile with a range of 1500 km.

The Brahmos short-range (295 km) missile is also submarine launch capable though it has already been installed on several Indian Navy ships for surface-to-surface (anti-ship, land-attack) roles. In fact, the ship-based nuclear capable Brahmos is in some ways already part of the nuclear triad but overt and hence targetable.

India thus has both nuclear-tipped missiles and the platforms from which to launch them. However, if the latter is surface operable true deterrence is missing because the platform is vulnerable to detection and destruction.

Detecting and disabling a submarine, particularly a nuclear powered submarine, is an altogether different ballgame.

The uncertainty that a nuclear submarine brings to the battlefield far outrange any other naval platform, is thus justifiably described as the ultimate deterrent. If the presence of a nuclear-power, nuclear weapons carrying submarine does not deter an enemy nothing else will.