Indian Missiles and Munitions Discussion

[John]

also, given its range, which is about double that of spyder, akash systems need not keep up at the same speed as entire armoured force. it would constitute the centrepiece of the mobile AD net with 2-3 batteries at the division level while the spyder and SP AA systems like the tungushka M1/shilka take care of things at tank squadron level.

Big advantage of Spyder is it uses active/ir guided missile and can better deal with saturation attacks and cruise missile. Where as Akash is limited by the FCR and it requires line of sight, in urban areas a low flying missile view could be obstructed by buildings. Also derby/python missile itself is superior to Akash in terms of speed and maneuverability (the ramjet is major limitation). That said Spyder is a system that exsists only on paper including the improved the variant with double the range, so it makes sense to procure Akash to replace the SA-6.

[jaladipc]

Sorry,posted the wrong link
here is actual one
http://www.deccanherald.com/content/503 ... ahmos.html

[sum]

Absolutely no news on the supposed "Nirbhay" firing a week back?

[jaladipc]

Absolutely no news on the supposed "Nirbhay" firing a week back?

Even if a Nirbhay test occured,there is no point of it coming out into public. Unlike BM`s,India dont have to disclose its cruise missile launches.

all we can do is,rely on panwallahs.

[manjgu]

what role does the green pine play in AD env ? or is it for ABM purposes??

[Rahul M]

also, given its range, which is about double that of spyder, akash systems need not keep up at the same speed as entire armoured force. it would constitute the centrepiece of the mobile AD net with 2-3 batteries at the division level while the spyder and SP AA systems like the tungushka M1/shilka take care of things at tank squadron level.

Big advantage of Spyder is it uses active/ir guided missile and can better deal with saturation attacks and cruise missile. Where as Akash is limited by the FCR and it requires line of sight, in urban areas a low flying missile view could be obstructed by buildings. Also derby/python missile itself is superior to Akash in terms of speed and maneuverability (the ramjet is major limitation). That said Spyder is a system that exsists only on paper including the improved the variant with double the range, so it makes sense to procure Akash to replace the SA-6.

spyder and akash cater to somewhat different roles and those comparisons don't quite cut it IMHO. akash is a medium range SAM while spyder is a short ranged QRM. also, I'm not aware of cruise missiles that are considered cheap enough to be used against armoured vehicles.
primary targets of akash in IA will be attack helicopters and CAS aircraft.

>> Big advantage of Spyder is it uses active/ir guided missile and can better deal with saturation attacks and cruise missile.

considering that an akash battery can engage 4 targets at a time and a number of such batteries with overlapping protection bubbles constitute an akash formation, the akash is more than adequate to handle any conceivable saturation attacks.

>>Where as Akash is limited by the FCR and it requires line of sight, in urban areas a low flying missile view could be obstructed by buildings.

firstly, NO AD missile system like this is intended to be used *in* urban areas. all SAMs for protecting urban sites are deployed outside urban clutter where their surveillance radars can have clear LOS. neither are the armoured formations, (that army akash groups will be tasked to protect) be deployed *inside* urban areas in general. also, if the SAMs don't have LOS to incoming cruise missiles, how will the cruise missiles have clear view of the targets co-located with akash ? how will it identify the fast moving tanks in the first place ? in fact, how many cruise missiles are used in general to attack dynamic ground targets anyway ? I can't remember any ATM.
oh and btw, the spyder systems will also require LOS for its main surveillance radar for initial tasking of all launches in LOAL modes. and in case a target suddenly appears over the spyder system, I seriously doubt if there will be sufficient time for the missiles to get a lock.
the situation will be worse if and when the longer ranged syder-MR comes along. at those ranges there will be no LOBL due to seeker limitations.

>> Also derby/python missile itself is superior to Akash in terms of speed and maneuverability (the ramjet is major limitation).

15G and full powered flight is a limitation ? of course an AAM based system will be maneuverable but it will also be significantly hampered by the fact that it will be coasting for much of its flight. any aircraft with good reserve power will throw the spyder off-target by quickly changing altitudes.
as for cruise missiles, how many cruise missiles maneuver in the middle of their flight path ? none ? the s-maneuver thingy etc comes up only in terminal phase, therefore it's a headache for the short ranged spyder but not the medium ranged akash.

[srai]

One question though , if we have so much faith in Akash and even the Army has certefied to it . Why do we need Spyder QRSAM.

I think that the Akash SAM requires more vehicles to support it, including radar and command and control, reload vehicle (both are there on Spyder too, but each missile is a lot lighter), but I think that its biggest disadvantage in being mobile is that its heavier and AFAIK fewer are carried per vehicle.

which means its a good SAM for area defence but not quite so great for mobile ops. the Spyder QRSAM is designed to be very mobile, with only 1 Command Control Unit vehicle per battery of 4 Missile Firing Units with 4 missiles each. so it can be embedded alongwith mobile strike and defensive groups as they move and protect it from fighters or gunships that may attack tanks and other mobile targets.
...

IA specifically had DRDO change the BMP vehicles (Rajendra Radar and Akash launcher) to be mounted on T-72 chassis for better mobility with its armored formations. So do you know of some details that even with the T-72 chassis change Akash system is still not mobile enough for the IA armored corps?

...
15G and full powered flight is a limitation ? of course an AAM based system will be maneuverable but it will also be significantly hampered by the fact that it will be coasting for much of its flight. any aircraft with good reserve power will throw the spyder off-target by quickly changing altitudes....

I read somewhere (I think with SA-6 engagement profiles/hit probabilities) that with a 15g missile maneuverability roughly equates to being able to shoot-down targets maneuvering at around 8g. And Akash's top speed of around ~M2.8 equates to it being to intercept targets flying at around M1.8 (600m/s).

Akash missile is of a "vintage" SA-6 design. So there are limitations that are inherent in its design when put in a modern context, such as speed (~M2.8), maneuverability (15g), distance (~30km), and size (700kg+). However, Akash designers have made up for the "short-comings" of the missile by vastly improving the radars, C4I, multi-target capability, automation, and employment (group formations). For a first operational indigenous SAM system, it is still a giant leap.

Instead of upgrading to extend the life of the Russian systems (which the IA and IAF have a lot of and updates long overdue), it is likely a portion of the 2 SA-6 Groups and 25+ SA-3 squadrons will be replaced by the Akash SAMs. Rest will be replaced by the Barak-8 SAM systems post 2014.

[Rahul M]

So there are limitations that are inherent in its design when put in a modern context, such as speed (~M2., maneuverability (15g), distance (~30km), and size (700kg+).

we have had these discussions before.

speed : 2.8 M as against 4 M for other missiles ? that ignores the fact that 4M is the top speed and the avg speed is much much lower while for the akash top speed will be very close to avg speed. effectively no difference. the aster-15 has a speed of 3 M, which I guess is the top speed.

maneuverability (15g) adequate for a missile that is powered till the end of its engagement envelope. higher maneuverability is required for the rocket powered SAMs because they are coasting in their intercept phase and won't have a chance to recover and re-engage.

range is a little lagging but that can be rectified with an additional booster, ala aster.

[Kanson]

From the TOI link:

"The missile can target an enemy aircraft up to 30 km away, at altitudes up to 18,000 meters
The missile is capable of carrying conventional as well as nuclear warheads with a payload of 60 kg.

What will a SAM of 30 KM range do with a Nuke warhead? do we have 60 kg compact nukes?

DDM, ignore.

It is not the first time that Akash is reported to have N warhead.

[Kanson]

Hot news on Sub-Brahmos ...sorry folks this is from telugu news and its in telugu


http://sakshi.com/main/SportsDetailsNor ... ubcatid=33

Translating from the above source. Emphasis and translational/transcription errors are mine:

Yet another powerful missile is taking shape in indian defense sphere. DRDO is developing this one with latest technology. The missile which is in
preliminary devlopmental phase was tested on thursday around 10 am. The secretive test conducted 40 nautical miles from Visakhapatnam was successful.

Camping in Visakhapatnam, a group of about 80 specialists from Hyderabad's DRDO (DRDL?) have been working hard on it for last few days. The group made
all necessary arrangements for the test and time to test was fixed for thursday.

As part of these arrangmenets a submarine from naval dockyard proceeded into waters of bay of bengal. Specialists from DRDO followed the submarine on INS
Sukanya. It has been learnt that, being a preliminary test, the missile was tested from submarine on to sea surface. During advanced testing, target to
be achieved will be designated. With the success of preliminary testing, advanced testing may be scheduled for February. According to sources, the missile
resembles Brahmos (Sagarika/Shourya?)

Prestigeous nuclear sumbmarine INS Arihant has already been developed. It was inaugerated last year on July 26th by Mr/Mrs Dr. Manmohan Singh. The
missile tested is believed to have been developed for nuclear submarine. Notably, during today's test, most of the officials were from DRDO with only a
handful of navy officials. With successful execution of this crucial preliminary test, various DRDO groups are elated.

Indian torpedo "Varunastra" was supposed to be tested around this time. It very well resembles like Brahmos. Further, if it is tested in Vizag, more probably it will be a torpedo test.

[Anujan]

I read somewhere (I think with SA-6 engagement profiles/hit probabilities) that with a 15g missile maneuverability roughly equates to being able to shoot-down targets maneuvering at around 8g. And Akash's top speed of around ~M2.8 equates to it being to intercept targets flying at around M1.8 (600m/s).

This is not quite that simple.

Assume that the missile is a fixed point in space and an aircraft is approaching it. Let the aircraft maneuver at X G's. It is enough for the missile to maneuver at the same X G's to line up to the aircraft & the aircraft is finished. So technically, when the missile is closing in on the aircraft an ability to pull the same G's as the aircraft will be a sure kill! (ofcourse a slight excess is needed to account for the time needed for the sensors and actuators).

Then why this story of a missile needing to be more maneuverable than the aircraft?

Consider this. You are chasing the aircraft in a circle and the missile is slower than the aircraft. Then the only way to catch up is to turn in a tighter circle, so you cover less distance and hit the aircraft. This means that you have to be able to pull a higher G than the aircraft.

Typical AA missiles have a coast phase (say at Mach 4) and they have some Kinetic energy. This Kinetic energy is harnessed by the fins to maneuver the missile, which causes a loss of energy every time it turns. Now assuming that the missile is twice as fast as the aircraft and the aircraft is flying away, you can drain the energy by maneuvering, causing the closing speed to drop, till you can outrun the missile. Or vastly simplified, if the aircraft keeps going in a circle the missile will eventually drop down like a stone (if it hasnt caught up by then). So when the missile has a particular amount of energy, there is a particular zone in front of the missile which is a "no-escape" zone for an aircraft flying at a particular speed and ability to pull particular G. The missile has enough energy to maneuver and still have enough velocity to close the distance to the aircraft and hit it. (ofcourse, this does not take into account "fooling" the missile with jamming, chaff or flares. No-escape is just "theoretical" based on speed and ability to maneuver)

But what of missiles which burn their rocket motors continuously? If they are even slightly faster than the aircraft, and if they can pull slightly better G's than the aircraft, it is a sure kill!

Ofcourse, things like the speed at which sensors and actuators can work means that you have to be able to pull higher G's. So the missile performance is not a straight one to one mapping of missile G's to aircraft G's.

[Kanson]

^^ I think what Srai saying on Akash is right. For doing the same manoeuvre, the object with lesser speed experiences lesser Gs than an object with higher speed.

[sum]

Indian torpedo "Varunastra" was supposed to be tested around this time. It very well resembles like Brahmos. Further, if it is tested in Vizag, more probably it will be a torpedo test.

Kanson garu,

Thanks for the input. I think what you said makes sense ( though it made this jingo depressed who was expected the "mythical" Nirbhay)

[Rahul M]

^^ I think what Srai saying on Akash is right. For doing the same manoeuvre, the object with lesser speed experiences lesser Gs than an object with higher speed.

not sure of that. same manoeuvre is the operative word. a coasting missile would need to do a much more violent maneuver because it has no reserve power to fall back upon if it misses the first time. a powered missile can keep up with a maneuvering target on account of its reserve power with much less violent maneuvers and hence lesser g-forces.

[negi]

^ Rahul I wonder whether 're-enagement' is possible specially for a missile with a short range of 30km. I am under the impression the whole engagement takes places in a minute or so hardly any time or chance for re-engaging a target.

I do realize for long range intercepts it might very well be possible that target disappear amidst clutter or some hill/mountain for a short time and missile would have to re correct the course once the seeker/GBR again starts tracking the target but once in terminal stages there is no chance of a miss if the missile misses we are talking about a lot of corrective maneuvering to re engage the 'Behind the enemy lines' kind of maneuvering is unheard of and imo not realistic. In case of a missile with active seeker or IIR seeker if the missile misses the target (I don't expect missile to miss head on or in simple tail chase approach) the chances of it being out of its FOV will be very high and from there on it will keep hunting for the target . Akash has a big airframe and obviously a lot heavier than other small AAMs yet it pulls just 15gs and with no TVC or movable fore planes I wonder the kind of maneuverability missile is capable of which is required for re engaging a supersonic target.

[ramana]

sum, It also says the sub was surfaced and not underwater.

[arun]

Agni-III test launch before Sunday:

CHENNAI, February 3, 2010

Fourth launch of Agni-III before Sunday

T. S. Subramanian

Intense preparations are under way on the tiny Wheeler Island, off Damra village on the Orissa coast, for the launch of ballistic missile Agni-III before Sunday.

A new version of K 15 to be test launched later this month:

The coming weeks/months will be hectic for the DRDO with one more launch of K-15 missile this month from a submerged pontoon off the coast of Visakhapatnam. The pontoon will simulate the conditions of a submarine. K-15 had been launched earlier from submerged pontoons, but this is a different version.

Shourya test launch planned in June:

Shourya, which is the land-version of the underwater-launched K-15 missile, will have its second flight around June

AAD test launch planned in September:

The fourth flight of India’s interceptor missile, which can knock out adversarial ballistic missiles at an altitude of 130 km, is scheduled for September.

Read it all:

Fourth launch of Agni-III before Sunday

[vavinash]

A BMD missile intercepting at 130 km will be AD-1 not AAD. AAD can only intercept at a max altitude of 30 km. PAD at 80 Km.

[John]

15G and full powered flight is a limitation ? of course an AAM based system will be maneuverable but it will also be significantly hampered by the fact that it will be coasting for much of its flight. any aircraft with good reserve power will throw the spyder off-target by quickly changing altitudes.
as for cruise missiles, how many cruise missiles maneuver in the middle of their flight path ? none ? the s-maneuver thingy etc comes up only in terminal phase, therefore it's a headache for the short ranged spyder but not the medium ranged akash.

I believe Barak-8 is supposed to be capable of 60g ,Python/Derby are capable of similar figures?

As for Cruise missiles (even the TLAM-N) yes they can be programmed to perform maneuvers during their flight path not just in terminal phase (it does reduce their overall range).

speed : 2.8 M as against 4 M for other missiles ? that ignores the fact that 4M is the top speed and the avg speed is much much lower while for the akash top speed will be very close to avg speed. effectively no difference. the aster-15 has a speed of 3 M, which I guess is the top speed.

Where did you get aster speed figure from aster top speed is 1.4 km/sec where as Akash top speed is 600 m/s.

As i said before Akash is good replacement for SA-6 but Ramjet engine poses many drawbacks (hence the Russians were quick to replace it in their SA-11). DRDO needs to accelerate Akash 2 with extended range and solid propellant motor especially since it has funding for it.

[Craig Alpert]

India to buy more BrahMos missiles

The missile, known as BrahMos Block-2, can have a top speed of over Mach 5, which could make it virtually impossible to intercept, and can effectively engage even slightly visible ground targets. It has been designed primarily to meet the needs of the army.

"The army officials said they were pleased with last year's ground trials of the missile, and approved of putting it into service," Pillai said.

The company has also been developing another version of the missile for Air Force, the BrahMos-A missile, with a reduced mass and increased aerodynamic stability. The Indian Air Force chose the Russian-made SU-30 MKI Flanker-H multirole fighter as the trial platform for the missile.

"[This] version of the missile is now ready. Air trials will commence in 2011, and by 2012, we are planning to fit the missiles onto aircraft," Pillai said.

The required modifications of the SU-30 MKI for integration with the BrahMos-A missile system are being carried out by the Hindustan Aeronautics Limited (HAL) and Russia's Sukhoi Design Bureau.

Mach 5??? last I heard it was at Mach 2.8 or atleast that's the speed for Block 1..
Maybe I'm understanding it wrong.. TOP speed around Mach 5, cruise speed around Mach 2.8???

[Anujan]

^^^

DDM confusing Brahmos-2 with Brahmos Block 2.

Brahmos-2 (still under development and a few years away) will have a 5.5 mach speed (reportedly achieved in "lab tests"). From what I can say, Brahmos Block 2 is old Brahmos with updated software (and possibly new seekers)

[Kartik]

Then why this story of a missile needing to be more maneuverable than the aircraft?

Consider this. You are chasing the aircraft in a circle and the missile is slower than the aircraft. Then the only way to catch up is to turn in a tighter circle, so you cover less distance and hit the aircraft. This means that you have to be able to pull a higher G than the aircraft.

Typical AA missiles have a coast phase (say at Mach 4) and they have some Kinetic energy. This Kinetic energy is harnessed by the fins to maneuver the missile, which causes a loss of energy every time it turns. Now assuming that the missile is twice as fast as the aircraft and the aircraft is flying away, you can drain the energy by maneuvering, causing the closing speed to drop, till you can outrun the missile. Or vastly simplified, if the aircraft keeps going in a circle the missile will eventually drop down like a stone (if it hasnt caught up by then). So when the missile has a particular amount of energy, there is a particular zone in front of the missile which is a "no-escape" zone for an aircraft flying at a particular speed and ability to pull particular G. The missile has enough energy to maneuver and still have enough velocity to close the distance to the aircraft and hit it. (ofcourse, this does not take into account "fooling" the missile with jamming, chaff or flares. No-escape is just "theoretical" based on speed and ability to maneuver)

But what of missiles which burn their rocket motors continuously? If they are even slightly faster than the aircraft, and if they can pull slightly better G's than the aircraft, it is a sure kill!

Ofcourse, things like the speed at which sensors and actuators can work means that you have to be able to pull higher G's. So the missile performance is not a straight one to one mapping of missile G's to aircraft G's.

[/quote]

the speeds at which modern air to air missiles fly is so high that any turn (even if its not the tightest of turns) is bound to lead to very high G forces. To have a missile with high speed (so you can fire in tailchase mode and it can catch up with a fleeing fighter or in head-on mode it gives the on-coming fighter very little time to react) you need to be able to make the missile airframe withstand humongous g forces just so it can turn quickly as the (most likely) sub-sonic fighter jinks. The fighter may pull only 7-8Gs but then its flying a lot slower, so it can still pull tight turns. For the missile to pull such turns at high super-sonic speeds would require that its actuators work that hard, and that its airframe withstand that much g's or else you put thrust-vectoring on board. All these features add weight.

If you don't want to make it capable of taking such high g-loads (some modern IR missiles quote 40-50 g's) you could go with lower speed air to air missile so you don't generate very high g forces and you can correspondingly reduce weight. But then operationally it may be useless, for instance in a tail-chase mode it could be out run and may not manage to catch up with its target.

So the factors that need to be taken into account for a missile design are:
- engagement profile desired as per requirements. the larger the engagement profile required, the more is the energy and speed required
- speed which will in turn decide how much propellant is required
- motor size and burn time - for e.g. ASRAAM designer MBDA claims that with a diameter of 6.5 inches, it has 70% more motor burn time than missiles with 5 in diameters, which means that it is powered for a longer period, which means longer engagement range as well as more energy at the fag end of its flight, which translates to higher probability of a kill. It may not have the very high g- force capability of the IRIS-T, but it compensates for it with a very long range for an IR missile and a better probability of getting a kill at those long ranges
- drag reduction features. the new R-77 upgrade features something called as a "boat-tail" design on its fins that allow drag reduction
- and all of these factors will decide how much the airframe will weigh. the higher the g-forces, the higher is the structural integrity requirement of the airframe. that means higher cost as better and stronger materials are required.

On the new R-77 upgrade, as per AW&ST's recent article, there is a 30% increase in range to 110 km and a corresponding increase in weight from 175kgs to 190 kgs. New seeker, new fins and ability to use lofted trajectory for better range are other features on this upgrade.

[Craig Alpert]

^^^

DDM confusing Brahmos-2 with Brahmos Block 2.

Brahmos-2 (still under development and a few years away) will have a 5.5 mach speed (reportedly achieved in "lab tests"). From what I can say, Brahmos Block 2 is old Brahmos with updated software (and possibly new seekers)

I doubt it.. It's not normal DDM, it's RIA Novitsi... and they clearly mention BLOCK II...so that's very intriguing.. Mach 5 would make it HYPERSONIC.. interesting to say the least!

[shiv]

Some interesting AAM-talk on this page.

I would like some gyan regarding this since my naalij here is about high school physics level. G forces in a turn are dependent on acceleration. Acceleration is rate of change of velocity. If the angular velocity of both objects in the same, shouldn't they both have the same G forces if they are turning at the same rate ? This assumes that the "outer circle" (aircraft) is moving at a much faster speed than the missile (inner circle).

Now if the missile is fired (from inside the circle) at a point where the aircraft is expected to be in a few seconds time, the missile does not even have to suffer those lateral G forces that it would need if it was turning at the same rate as the aircraft. It merely needs to accelerate in a direction which the aircraft will reach in some time.

As long as the missile is inside a circle in which both aircraft and missile are travelling, the missile will not have to experience the same G forces as the aircraft even if the aircraft makes evasive maneuvers. By turning the aircraft is in effect wasting part of its energy in allowing the missile to "catch up", while the missile itself is using all its energy to catch up.

I would have thought that this is an ideal situation for the missile. Would it not be true to say that the only way for the aircraft to escape would be to concentrate on using all its energy in making the missile do more work (expend more energy). This would be IMO to break away from a turn and start accelerating in a direction away from the missile. At this stage the missile would need its maximum acceleration to catch up and may burn itself out before it does, depending on the initial launch conditions. Also at this stage chaff and flares might help.

As the missile gets closer, a sudden change of direction, such as a Cobra could throw the missile off track because when the missile is closer to the aircraft, it will need to exert a higher G force (and expend energy) to follow the maneuvering target.

For the same reason a missile fired at an aircraft coming directly at the missile firing aircraft (but perhaps at a lower or higher altitude) will require the missile to perform some fancy Hi-G energy wasting turns to change its direction. The G forces will be small if the target is far away - but as it gets closer the missile will have to perform a tighter turn. But the missile will get to the target that much more quickly and I would imagine that the target aircraft would have to perform some fancy maneuvers to avoid the missile. Even if my guesswork is correct - I wonder what would be the best evasive action for a plane that finds a missile approaching head on?

A third scenario would be an end on missile that overshoots the target and becomes tail chase

[Masaru]

x - post

Su-30 MKI to be armed with BrahMos missiles

India's fleet of Su-30MKI Flanker-H fighter jets could be armed with BrahMos missiles by 2012, the vice president of the Irkut
Corporation said at the Singapore Airshow 2010.

"The modernisation programme includes re-equipping of some 100 Su-30MKI fighters, which are currently in service with the Indian Air Force," Vladimir Sautov said Thursday.

[Craig Alpert]

BEL bags Rs 4,279 crore deal for Akash missiles

05 Feb 2010 8ak: Bangalore-based defence publics sector undertaking (DPSU), Bharat Electricals Limited (BEL) has bagged an order for 750 additional Akash Surface-to-Air-Missile (SAM) worth Rs 4,279. The order comes as a boost for the DPSU as the IAF was not happy with the missile and had floated a proposal to abandon the program.

Defence Minister A.K. Antony said "Earlier, there was a proposal to abandon the Akash missile system. But the IAF deployed it on a trial basis and is now happy with the system. After testing it in two squadrons last year, they have placed orders for six more squadrons. This shows the Defence Research and Development Organisation (DRDO) and BEL are capable of producing equipment for our armed forces,”.

The order is over and above the Rs 1,221 crore deal the IAF had signed with BEL for supplying 250-Akash missiles for two squadrons. The fresh order for 750 SAM will enable the IAF to raise six-additional squadrons of Akash missiles.

The missile can target aircraft up to 30 km away, at altitudes up to 18,000 m. Akash can be fired from both tracked and wheeled platforms. It is capable of carrying nuclear warheads with a payload of 60kg. The first test flight of Akash missile was conducted in 1990, with development flights up to March 1997. The Akash Project has been the most expensive missile project ever undertaken by the government of India in the 20th century. Total development costs for the missile and associated radars and systems was almost $US120 million. MOST EXPENSIVE and then they quote it at ~$120 Million..... Man don't know what they are smoking, but would sure like to get my hands on some...Compared to the rest of the countries, and designing it SPECIFICALLY for the IAF this is money WELL SPENT and infact they outta spend more to increase the speed/range of the missile while decreasing the WEIGHT and reaction time

The missile has a launch weight of 720 kg, a diameter of 35 cm and a length of 5.78 metres and flies at supersonic speed, reaching around Mach 2.5. The Akash missile has been developed jointly by DRDO and BEL as part of the Integrated Guided Missile Development Program initiated by the government in the 1983 to develop futuristic missiles technology based on hypersonic rockets to provide a potent weapon to the armed forces in order to enhance national security. Other missiles developed under this program include the 700km-range nuclear- capable submarine- launched ballistic missile (SLBM) Sagarika, the 350km-range Prithvi, 3,500km-range Agni 3, Nag anti-tank missile and Trishul SAM.

A study the blue-print of IGMP shows the advancement that India has made over the years in development of missile technology. The program underlines India's capability to attain self-reliance and present a deterrent from a hostile attack. Armed forces are however concerned about the low rate of production of these missiles and the long time it is taking to induct them into the services.

[Rahul M]

x - post

India's fleet of Su-30MKI Flanker-H ..........

NATO reporting name for su-30mki.

[David Saenz]

Apologies if posted earlier..
Barak-2 LR-SAM maiden flight later this year

The Barak-2 version will have a longer range between 120-350Km in comparison to the Barak MR-SAM, which has a range of 60 km vertically.

[Bheem]

With Orders for Akash missiles, earlier orders for CARs and WLR, it would be worth noting that Akash Programme has already netted orders of around Rs. 10,000 crores which would make it the biggest indigenous production programme in Indian defence (Note LCA will have lesser net indigenous addition at present, though it may overtake Akash programme later)

[Kartik]

I would like some gyan regarding this since my naalij here is about high school physics level. G forces in a turn are dependent on acceleration. Acceleration is rate of change of velocity. If the angular velocity of both objects in the same, shouldn't they both have the same G forces if they are turning at the same rate ? This assumes that the "outer circle" (aircraft) is moving at a much faster speed than the missile (inner circle).

the centrifugal force is the one that we're referring to here as the G-forces. its basically a product of mass and velocity squared, divided by the radius of the circle around which the object revolves. The larger the value of 'r' (the less tight the turn), the lower is the centrifugal acceleration for same mass and velocity. If the angular velocity is to be taken into account, then formula is slightly different- mass*radius of turn * square of angular velocity (since angular velocity is velocity divided by radius of the angle). So if two objects have same angular velocity, and are prescribing a circular path of the same radius, they still may have different centrifugal forces acting on them depending on their mass.

Now if the missile is fired (from inside the circle) at a point where the aircraft is expected to be in a few seconds time, the missile does not even have to suffer those lateral G forces that it would need if it was turning at the same rate as the aircraft. It merely needs to accelerate in a direction which the aircraft will reach in some time.

As long as the missile is inside a circle in which both aircraft and missile are travelling, the missile will not have to experience the same G forces as the aircraft even if the aircraft makes evasive maneuvers. By turning the aircraft is in effect wasting part of its energy in allowing the missile to "catch up", while the missile itself is using all its energy to catch up.

sorry doc, totally lost you here..maybe you could re-explain more clearly calling the enemy as bogey and the fighter that launched the missile as something else.

I would have thought that this is an ideal situation for the missile. Would it not be true to say that the only way for the aircraft to escape would be to concentrate on using all its energy in making the missile do more work (expend more energy). This would be IMO to break away from a turn and start accelerating in a direction away from the missile. At this stage the missile would need its maximum acceleration to catch up and may burn itself out before it does, depending on the initial launch conditions. Also at this stage chaff and flares might help.

As the missile gets closer, a sudden change of direction, such as a Cobra could throw the missile off track because when the missile is closer to the aircraft, it will need to exert a higher G force (and expend energy) to follow the maneuvering target.

the last thing a pilots wants in a situation where he is being chased by a missile is to lose energy and the Cobra basically reduces airspeed to nearly zero. In most cases, it will not result in a missile overshooting the target but finding it to be a rather large, lazy, juicy one. For it to succeed the pilot would need to time it to perfection just a second or two before the missile is to impact.

When a pilot has had some fore-warning about an approaching missile my guess would be that he would first of all try to get into a position where he has plenty of energy to allow for sustained turning without becomng a sitting duck and try to run in the opposite direction so the missile loses energy by the time it reaches him and then any jinking maneuver would be far more successful. that would mean accelerate immediately, and then keep a watch out in the sector from which the missile is approaching.

depending on whether an IR or Active guided missile is fired, things will differ. if its IR, only a MAWS or Eyeball Mk1 will even warn a pilot that something of this sort has happened, which is why IR long-range missiles like the MICA-IR and ASRAAM are dangerous- they are capable of being fired outside of the max. ranges of most MAWS sensors and too far to be seen by naked eye. When an IR missile is fired within WVR, both MAWS and the pilot are likely to spot the missile plume as it leaves the fighter that launched it. within a few seconds of this, the guy will be punching flares, chaff and diving down to try and confuse the seeker against ground clutter. go up into the clear blue sky and you offer a perfect target as most seekers fare better in this condition. using After burner would only increase the fighter's IR signature and may serve to negate the effect of flares although modern IIR seekers like those on the Python 5 or AIM-9X will easily dismiss flares. but the best option is to dive and then alter one's path suddenly and then re-accelerate and again alter the flight path. If you do this from too far out, the missile's will simply be making small energy loss turns with plenty of energy intact. If you do it too late, well it may be too late.

with a BVR missile, the RWR will warn about the sector from which the fighter is being targeted. But even this advantage can be beaten by a tactic that Gripens use- one fighter illuminates the target, then passes on target data via the TIDLS datalink to a "radar silent" Gripen separated by several kms which fires the active guided missile. the targeted fighter's RWR will spot the Gripen that illuminated it, and the pilot will expect the missile to come from this quadrant, consequently doing this best to jam that aircraft's radar while it still has him illuminated. All the while, the missile would be coming from a different quadrant, from a fighter that isn't even radiating and could take the pilot by suprise even as the RWR keeps ringing (although I'd expect this is possible only when the missile's onboard seeker has Locked-on-before-launch). the best way to deal with BVR missiles are fiber optic active towed decoys like the kind the Typhoon and Super Hornet have. Its an area where the IAF will need to invest in for its fighters considering the AMRAAM, SD-10 and possibly MICA coming into PAF service.

I don't know if I even answered any question of yours Shivji. sorry if I didn't.

[Mihir.D]

For the Akash Block-2 , should the DRDO continue with the Ramjet based propulsion or the should it move to a more regular propulsion? The ramjet seems to have its associated disadvantages. Is there any document out on the specs of Akash 2 ?

[Anabhaya]

I doubt there is a follow up development of Akash. It will probably be Barak all the way. No?

[Anujan]

Also derby/python missile itself is superior to Akash in terms of speed and maneuverability (the ramjet is major limitation).

I am not so sure that "Ramjet is a major limitation". Raytheon proposed the "Future Medium-Range Air-to-Air Missile", an improvement of AIM-120 AMRAAM with guess what? Ramjet. http://www.hughesmissiles.com/develop_p ... fmraam.htm

MBDA Meteor has Ramjet propulsion! http://en.wikipedia.org/wiki/MBDA_Meteor The planned improvement to R-77, the R-77M1 will have Ramjet propulsion. In fact most long range AA missiles seem to be moving in that direction.

Then what is the basis to claim that Ramjet has a major limitation?

You might also find this interesting "Performance simulations of a rocket and a ramjet Air-To-Air Missile"

(I do note that these are all A-to-A missiles)

[neerajb]

So there are limitations that are inherent in its design when put in a modern context, such as speed (~M2., maneuverability (15g), distance (~30km), and size (700kg+).

we have had these discussions before.

speed : 2.8 M as against 4 M for other missiles ? that ignores the fact that 4M is the top speed and the avg speed is much much lower while for the akash top speed will be very close to avg speed. effectively no difference. the aster-15 has a speed of 3 M, which I guess is the top speed.

My understanding is that comparing average speed of mach 2.8 with top speed of other missiles is unfair/inaccurate. The higher speed SAMs will burn their motors, achieve their top speed and then they'll be coasting to their targets at much lower speeds. Time to target and effective range is a function of average speed and not the top speed. Infact ramjet is not a limitation but an advantage.

The Ram jet system enables powered intercept, high maneuverability, much higher terminal velocities, high average speed, lesser reaction time, lower flight time and better engagements of receeder targets vis-à-vis boost coast type of missiles.

http://www.akashsam.com/about.htm

Cheers....

[tejas]

My beef against Akash is not its speed but its pathetically short range. 28-30 km is abysmal.

[Rahul M]

My beef against Akash is not its speed but its pathetically short range. 28-30 km is abysmal.

it's a 'medium' range SAM, in what way is 30 km 'abysmal' ? what pray is the range of the 'modern' aster-15 on the 'ultra modern' RN Type 45 frigate, FREMM, horizon etc ?

that's right, abysmal 30km onlee saar !

in any case, there's a proposal to develop a longer ranged version with an additional booster stage that will push its range towards the 50-60 km mark.

[ramdas]

The Hindu reported that Agni III was to be tested before Sunday. Still no sign of the test. Are they being cancelled by pacifist elements in the govt ?

[krishnan]

Before which sunday?

[ramdas]

Strictly speaking, the Hindu article did not specify which sunday. Given there was an Indian Express article saying Feb 6-8, it means the test should have taken place before Feb 7, i.e, on Feb 6.

[ramana]

Please start new thread on the test whenever it happens.

Thanks ramana