Nirbhay (Fearless) is an intermediate-range (1000km), stealthy, subsonic land-attack cruise missile with terrain hugging (30m AGL) capability under development by Advanced Systems Laboratory (ASL) in Hyderabad since 2007.
The missile is being developed to supplement the 300-km range supersonic Brahmos missile.
"The need was felt for a subsonic cruise missile that will be capable of being launched from multiple platforms in land, air, and sea," says the ASL director.
Nirbhay is a two stage missile. A solid fuel rocket motor serves as its first stage and accelerates the the missile after launch to cruise speed when a turbojet engine in the second stage takes over.
Nirbhay is reportedly based on the Lakshay-2 pilotless target aircraft developed by ADE, which also uses a solid propellant rocket motor for launch and a turbojet for cruise. [via Hindu]
It is relevant to note that DRDO recently developed a Digital Flight Control System incorporating Autonomous Way Point Navigation with Global Position Satellite updates for the Laskhay-2 which during a test flight in January 2012 demonstrated its ability to fly at heights ranging from 12m to 800m.
Nirbhay will be a terrain hugging (30m AGL), stealthy missile capable of delivering different warheads as per mission requirement.
The missile will be capable of carrying 24 types of warhead but it is not clear if it would be nuclear capable.
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 Nirbay, "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.
The Hindu report is riddled with a likely inaccuracy. For example, it quotes a DRDO source as saying "the second stage has a turbo-prop engine, akin to an aircraft's." It's likely the source, or the reporter meant turbo-fan, not turbo-prop.
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.
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.
A loitering ability at a range of 750 km would require reliable satellite based communication link and it's moot if India has that as of now. Besides, loitering deep in enemy territory would make the missile susceptible to enemy defenses.
For the 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.
It is possible that the Air Force satellite GSAT-7A will give the IAF an ability to control the drone right through to its limiting range.
The loitering ability of the missile would allow it to pick the right target from amid dummy targets placed to confuse the missile.
Fitted with a nuclear warhead, Nirbhay's loitering capabilities makes no sense and it's low loitering speed would make it highly vulnerable. It is likely the loitering ability is designed for conventional warheads only.
DRDO scientists have said that the missile can engage one of multiple targets. In many press reports this has been interpreted as an ability to engage multiple targets.
It's likely DRDO officials were referring to missiles ability to loiter and pick the right target.
The missile is too small to carry a payload large enough to engage multiple targets. Besides, any bombs carried by the missile would have to be optically guided over extreme ranges.
DRDO scientists have in the past talked about a missile that can 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, subjecting it to rigorous testing for a relaunch 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.
The missile is being designed to match the capabilities of the US Tomahawk and its Pakistan developed variant Babur.
The debut test of the Nirbhay cruise missile at 11:50 AM on March 12, 2013 was aborted after about 20 mins of flight.
The following is the DRDO statement on the test.
"Long range cruise missile Nirbhay was successfully launched today at 1150 hrs from launch complex, Chandipur, Odisha, meeting the basic mission objectives successfully. After travelling approximately mid-way, deviations were observed from its intended course. Further, flight was terminated to ensure coastal safety."
The test was planned to the max range of the missile, which is 1,000 km.
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.
The missile was flying at a height of 4.5 km when the mission was aborted.
DRDO had setup make-shift stations along the East Coast to track the missile during its flight.
DRDO switched off the missile's engine after it veered towards the coast, having travelling around 300 kms (30% of its envisage range.). All the parameters till then were exactly as planned.
DRDO's Avinash Chander, Chief Controller (Missiles and Strategic Systems), told The Hindu, "All the aspects of cruise vehicle were tested and verified. That is a major achievement."
He added that DRDO might take a couple of months to determine the reason for the deviation and take remedial measures before conducting another test.
He told Business-standard, "I would call the test 80 per cent successful. The Nirbhay demonstrated that it could take off correctly, establish a cruise profile, and navigate to its initial waypoints. These were new performance parameters that we had never tested before, so we are satisfied that the test proved those. But then, one of the sub-systems malfunctioned and we had to terminate the test. All that remains is to determine why this happened and to rectify the flaw."
On May 8, 2013, Defense Minister A K Antony today told the Rajya Sabha in a written reply that scientists have identified the problem in Nirbhay cruise missile, which led to its malfunction during the first test flight last month, and corrective design is being implemented.
"Scientists have identified that Inertial Navigation System has malfunctioned and corrective design/modification are being implemented," he wrote.
DRDO officials have acknowledged the missile is powered by an imported turbofan engine, which is likely to be the Saturn 36MT
Turbofan two-shaft turbofan engine with coaxial shafts cascades of low and high pressure.
The engine powers the Russian Kh-59M Ovod-M (AS-18 'Kazoo') LACM and the Kh-59MK anti-shipping missile.
High pressure stage - osediagonalny compressor and single-stage axial turbine;
Low pressure stage - of wide-stage fan blades and a single-stage axial turbine;
Annular combustion chamber;
Standalone oil system;
Electronic-hydraulic control system;
Built-in electric output of 4 kW.
The main characteristics of the engine:
Max Thrust: 450kgf
Specific fuel consumption at maximum capacity, kg / kgf * h 0.71
Dry weight, kg 82
Weight in the delivery condition, kg 100
Maximum diameter in mm 330
Maximum length, mm 850
The missile was tested for the first time on Tuesday, March 12, 2013. The test was partially successful.
On January 25, 2013, PTI reported the DRDO chief VK Sarswat as saying the missile would be tested in February.
"[The missile] is in the final stage of integration and we expect to launch it next month”, Mr. Saraswat said.
Saraswat claimed the missile has good loitering capability, good control and guidance, high degree of accuracy in terms of impact and very good stealth features.
ADE Director P S Krishnan said Nirbhay would be launched from Integrated Test Range at Chandipur in Orissa.
On September 14, The Hindu quoted DRDO chief VK Sarswat as saying the missile would be tested in October or November 2012.
On September 5, 2012, TOI reported that the missile would be tested from Wheeler Island in October 2012.
DRDO director general V K Saraswat told TOI that the missile with a turbo jet is now ready to be test-fired.
"It is a highly advanced missile with strong capabilities. We have made an assessment of it and we are almost prepared for a test launch," Saraswat said.
In March 2012, a DRDO official told The Hindu that the missile will be tested in early April 2012.
In November 2011, a DRDO official told PTI, "We are looking to test-fire the new sub-sonic cruise missile in the first quarter of 2012."
On February 11, during Aero India 2011, Defense Research and Development Organisation (DRDO) chief VK Saraswat said the Nirbhay was almost in place and it would be ready by early next year.
“Integration of the engine is under way,” he said.
First test flight is expected in 2012, Saraswat said.
On April 11, 2010, DRDO Chief Dr V K Saraswat said, "[The] missile is getting into some shape."
He was in Bangalore to deliver the keynote address at a national convention on 'The Frontiers of Aeronautical Technologies', organised by the Aeronautical Society of India.
On February 2010, DRDO Chief said that Nirbhay has not reached integration stage, but development is on.
"The development of the system is on. We have completed the propulsion system's design. But we have not integrated it.
Once we reach the integration stage, we will show it you," he told reporters.