N-sub's first missile test this month

India's first nuclear-powered submarine Arihant is likely to carry out its missile tests this winter so that the submarine becomes ready for operational use early next year.

“The tests held so far has been successful. In October, we will fire Nirbhay missile from the submarine which will be followed by firing of another type of missile,” defence ministry sources said.

While Nirbhay is a 1000-km-long range subsonic cruise missile, the next missile would be India's first Subamrine Launched Ballistic Missile (SLBM), which has a range of about 700 km. The SLBM was successfully test fired in 2013 from an under-water platform – more than a year before Arihant left for its sea trial in December, 2014.

Though the DRDO did not disclose the SLBM's range after the test, there were reports that defence scientists were developing two SLBMs – one with a range of about 700 km (K-15) and a second one whose range is upwards of 3000 km (K-4).  The plan now is to ready the submarine for operational use for Indian Navy during the International Fleet Review scheduled in February, 2016.