India recently had another successful test of their Prithvi II ballistic missile. This is progress because in September 2010, a Prithvi II test failed as the rocket motor began burning fuel but not enough to get it off the launcher. There was a lot of smoke and confusion but no launch. This was a user trial where military crews were making sure they were able to use a new weapon that had been successfully completed testing using manufacturer personnel to operate it. This is a common practice but particularly necessary in India, where the manufacturers often cut corners during development and testing. The troops on the military launch crews are usually not privy to these workarounds, and the developers sometimes just keep their fingers crossed that the troops can handle things on their own. For example, in 2009, the first user test of the ground launched BrahMos cruise missile failed. Not a major problem, it turned out. After a few months, everything was put right. That’s what happened with the Prithvi II.
The first successful test of the 4.6 ton Prithvi II took place in 2009, and it successfully hit a target 350 kilometers away. The 2010 launch was to test the ability of the missile to carry a half ton warhead. This is the minimum size for a nuclear warhead. Used with a nuclear warhead Prithvi II is a strategic weapon, since it can put those nuclear warheads on major targets within neighboring Pakistan. In the last three years Prithvi II has been improved to the point where it can reach targets 350 kilometers away while carrying a one ton warhead.
A Prithvi III is in development. This is the Prithvi II modified to be operated from ships. This missile can carry a half ton warhead 600 kilometers. The increase in range and warhead weight for the Prithvi III was achieved by using a solid fuel rocket motor and adding a second stage with a liquid fuel motor. The Prithvi II uses a liquid fuel rocket. The navy has not installed the Prithvi III on any of its ships because it was discovered that the liquid fuel was too dangerous to handle aboard a ship at sea.
The Prithvi is a ballistic missile that reaches its target within 5-10 minutes of launch and was originally developed as a shorter range (150 kilometers) missile. Prithvi uses liquid fuel, meaning it takes up to an hour to ready for launch. In 2013, India announced that it is replacing over a hundred Prithvi I ballistic missiles with the solid fuel Prahar. While the air force controls long range ballistic missiles, the army has long been supplied with some shorter range Prithvi Is. This is a single stage, road mobile, liquid fuel battlefield support missile that weighs 4.4 tons and is 9 meters (27.3 feet) long, 110cm in diameter and costing about a million dollars each. Introduced in 1994, the army version has a 150 kilometer range and carries a one ton warhead.
The Prahar is more compact and reliable. It weighs 1.3 tons, is 7.3 meters (23.6 feet) long, and 42cm in diameter, costing less than a million dollars each and carrying a 200 kg (440 pound) warhead. Prahar can be carried and fired from a TEL (Transporter Erector Launcher) that will haul six Prahars, each in a sealed container. Prahar can carry nuclear or conventional warheads and the TEL can fire salvos of up to six missiles, each in quick succession. The guidance system brings the missile to within ten meters of its aiming point. This is more than twice as accurate as Prithvi I. Most importantly, a Prahar can be fired within minutes of receiving the order while the Prithvi I takes over an hour to fuel and prepare for launch.
Prithvi I is similar to the old Russian SCUD, which is a direct descendent of the first ballistic missile, the German V-2 in World War II. The U.S. produced the Corporal missile as an equivalent to the SCUD but replaced it with solid fuel missiles in the 1960s. Russia replaced its SCUDS in the 1970s and the U.S. replaced its liquid fuel battlefield missiles a decade earlier. But a lot of SCUD type missiles remain in service around the world. India is in the process of replacing most of its liquid fuel missiles with solid fuel types.