Thursday, January 16, 2014

Nirbhay Cruise Missile Capability Analysis

Nirbhay Cruise Missile Debut Test on March 12, 2013. Photo Credit: DRDO

The second test of the Nibrhay cruise missile is due (The Hindu had reported on November 24, 2013 that the test would take place in December 2013) on Friday, October 17, 2014 and this post presents a recap and analysis of the missile's reported capabilities.

The debut test of the Nirbhay cruise missile on March 12, 2013 was aborted after about 20 mins of flight. A DRDO statement following the test said, "After travelling approximately mid-way, deviations were observed from its intended course.  Further, flight was terminated to ensure coastal safety."

Following launch from a road mobile launcher, the first stage rocket booster separated, the second stage turbojet engine starter fired, and the engine attained full thrust; the missile reached a cruise speed of 0.7 M (460 k or 900 kph).

The missile is reported to have successfully navigated to two waypoints and was flying at a height of 4.5 km when the mission was aborted.

The test was planned to the max range of the missile, which is 1,000 km. The missile successfully covered half the distance, proving many of the critical systems of the missile such as vertical launch and boost, tip over to horizontal flight, engine light up and cruise at max turbojet power. DRDO correctly labels the test as a partial failure.

Nirbhay's Reported Capabilities

Nirbhay is projected to be a terrain hugging (30m AGL) stealthy cruise missile capable of delivering different warheads as per mission requirement.

A DRDO official told the press that the missile would be capable of carrying 24 types of warhead.

On March 11, 2013 The Hindu reported that the Nirbhay is capable of dropping bombs and coming back. The missile cruises at 500-m to 1-km and has a cruise speed of 0.67M.

A DRDO missile engineer told The Hindu of Nirbhay, "It will cruise in the atmosphere like an aircraft and it is capable of travelling up to 1,000 km. The biggest advantage with Nirbhay is that it can be launched from land, air and sea. It is a potent system. ”

An unnamed DRDO official reportedly told The Hindu in March 2012 that the Nirbhay will be able to carry multiple payloads and engage one of several targets.

“Even if there are multiple targets, it can pick out a target and attack it. It is a loitering missile; it can go round and round a target, perform several manoeuvres and take it apart. It has precision, endurance and accuracy. It is an important missile,” the official said.

Flight Profile

Nirbhay takes off vertically from a road mobile launcher using its first stage solid rocket motor booster. As it reaches 500-m to 1-km, it archs to a horizontal flight path and accelerates. On burn out, the first stage motor drops off and the second stage turbo-jet engine powered by aviation kerosene lights up. The missile then cruises to its target at a speed of 0.67 Mach.


Nirbhay has no LO shaping, though the missile has a clean design and a recessed, shielded air-intake to reduce radar signature, like in the US Tomahawk CM.


Loitering Missiles

Typically, a loitering missile can fly a search pattern over a wide area for identifying targets and relaying their location back to the command center, where these targets are engaged by direct attack PAMs or by other assets.

Toward the end of its mission, or when a priority target appears, the missile brakes out of its search pattern and attacks the target.

The Nirbhay's loitering capabilities are likely inspired by those of the Tactical Tomahawk or RGM/UGM-109E Tomahawk Land Attack Missile (TLAM Block IV). The missile has network-centric warfare-capabilities - it can use targeting data from multiple sensors (aircraft, UAVs, satellites, foot soldiers, tanks, ships) to find its target and its sensors can send data to these platforms - which allow it to be re-targeted during a loiter. Instead of attacking target coordinates stored in its memory, the missile can be directed to attack fresh co-ordinates uploaded in realtime.  The missile entered service with the US Navy in late 2004.

The TLAM-D carries 24 canisters containing 166 bobmlets (7-ea in 22 canisters and 6-ea in 2 canisters).  The missile can perform up to five separate bombing runs dispensing two canisters, one from each side, at a time during a run, allowing it to attack multiple targets. However, typically the missile dispenses all 24 canisters sequentially from back to front to ensure the density of bomblets on target is adequately destructive.

The DRDO official who reportedtly told the press that the missile would be able to carry 24 types of warhead was likely referring to this capability.

Nirbhay's Loitering Capability

A loitering ability at a range of 750 km would require reliable satellite based communication link, something India doesn't have yet. Besides, loitering deep in enemy territory would make the missile susceptible to enemy defenses.

For loitering to be effective, it would have to be from a height where the missile will be an easy target for enemy air defenses.  The missile's reported max speed of 0.67 M or approximately 400 kts should make it an easy target, despite the LO features, were it to loiter in contested airspace.

It's likely the Nirbhay will have separate versions, like the Tomahawk, for strategic (single nuclear warhead) and tactical (multiple munitions) use, with only the tactical version using loitering capabilities.

It is possible that the Air Force satellite GSAT-7A will give the IAF an ability to control the Nirbhay right through to its limiting range.

Most likely the Tactical version of the Nirbhay will operate at limited range so that it can remain effectively networked, with AWACS providing a high bandwidth data link.

Recoverable Missile

DRDO scientists have alluded to the Nirbhay having an ability to engage targets and return.

Even if the missile is capable of being recovered, like the Lakshay-2, it would be limited to a few reuses. The cost of recovering the missile and subjecting it to rigorous testing for reuse would likely be close to the cost of a new missile if it is being produced in large enough quantities.

Fitted with a nuclear warhead, Nirbhay's loitering capabilities makes no sense and it's low cruise speed make it highly vulnerable.

It is possible that the ability of the missile to return is a reference to a recall of the missile, but no reuse.

For additional details about the Nirbhay missile, please visit the link below

Nirbhay Cruise Missile - IDP Sentinel