Russian Air-to-Air missiles

Isos wrote:Rob Lee
@RALee85
·
12 févr.
According to Izvestia, Russia will develop a multi-functional long-range interceptor missile (MFRK DP) for MiG-31 and the MiG-41 to counter hypersonic missiles. The MFRK DP would carry several smaller missiles that would break away to search for targets.

This is the original Russian source:


https://iz.ru/972679/anton-lavrov-roman-kretcul/odnim-makhom-rossiia-razrabatyvaet-oruzhie-protiv-giperzvukovykh-raket

Russia has carried out theoretical studies on an ultra-long-range air-to-air missile (MPKR DP) with multiple warheads. One of the submunition would be the medium-range missile K-77M (Izdeliye 180) developed for the Su-57

What's the need for multiple warheads in air to air missiles? Any idea? Anybody?

Part about r-77M is only speculation.

The need for many submunitions is probably because hypersonic targets are very hard targets and you would need many missiles to hit one (increase chances).

If integrated into tu-160 they could destroy cargo planes above Atlantic and pacific.

An anti ship variant would also be nice. 3 or 4 mini missiles inside the big one would start 3 or 4 fires in a ship and could even destroy fregates and destroyers.

A smaller missile with this feature would be useful against drones.

An interesting piece about the R-37M and izd. 180/180PD:

https://en.topwar.ru/170125-otvet-rf-na-osnaschenie-lanserov-raketami-agm-183a-ne-zastavil-sebja-dolgo-zhdat-vympel-i-suhoj-v-igre.html

GarryB wrote:So the ramjet powered R-77 completed testing but was put on hold in 2012... that is rather odd... I have speculated before that it was because a scramjet powered missile would have rather better performance but probably would not cost much more... just a slightly more complex ramjet design to allow supersonic combustion of fuel...

That may well depend on exotic materials or new fabrication technologies, and MRAAM are items of which you need to have an stock of hundreds and thousands of pieces.

Given how secretive they are about the newer weapons for the Su-57, I would not be surprised if they continued with the development of the PD version and simply suppressed any public mention to it.

GarryB wrote:So the ramjet powered R-77 completed testing but was put on hold in 2012... that is rather odd... I have speculated before that it was because a scramjet powered missile would have rather better performance but probably would not cost much more... just a slightly more complex ramjet design to allow supersonic combustion of fuel...

They would have issues with the radar because of the genereted plasma on the front at hypersonic speeds.

Mach 4 is more than enough.

GarryB wrote:But that article basically said it had passed its tests and was pretty much ready to go in to service when it got suspended in 2012... if it was just about getting a long range jet powered missile in to service it is supposed to be ready.

Yes I know, to be honest I am not sure why they don't have them already in operation. One reason could be money, after all they are still operating old missiles and only recently started to seriously update their stocks. Other reason could be doctrine:

We see that a fighter, if aware enough time in advance, can normally shape the kinematics of the encounter so that it can defeat a long-range shot. Russian missiles up to date seem to assume that and not loose too much sweat trying to overcome that fact. For instance, R-77 with its lattice tail puts manoeuvrability first and even R-37M is not mainly intended against fighter type targets. But in any case, kinematically defeating an inbound missile means loosing initiative, typically having to turn away in order to reduce the rate at which the missile closes in.

Western designs on the other hand try to give the missile high speed at long ranges, even at the expense of having worst turning performance due to small aerodynamic surfaces. Trajectory on the AIM-120D was optimised (loft angle has a big influence on range) to keep high speeds at high altitudes well beyond 100 km, Meteor received small surfaces together with the throttling-capable ducted rocket engine for best end-game capabilities. Reason is that a fast missile has no need for tight manoeuvring, since the much slower target will not be capable of generating substantial separation, especially at high altitudes. It seems that the biggest difference between AIM-120 and R-77 is aerodynamics, and by all accounts K-77M will abandon the lattice design and match AIM-120D's stated range close to 200 km in ideal conditions.

So, they might have abandoned the 180PD with lattice tail, but they might use that engine and design elements for a newer missile, similar to the Meteor. I would add that, for a plane like Su-57, it would be very beneficial to have such. Potentially, it could be carried in bigger amounts than R-37M and be more effective against fighter-type targets (due to lower drag and cost and better manoeuvrability). On the other hand, the strategy of the Su-57 in the air superiority role seems dependent on high-speed and altitude and long range. It should have the tools to force opposing fighters to abandon their attack or escort missions, not to loose initiative to lesser fighters, due to inferior missiles. The range of very low drag missiles like AIM-120 is best against high flying targets, and flying very fast in little dense air demands many km for a fighter to turn away from an attacking missile, which also adds to the range of the shot, because the fighter would make a major contribution itself to closing the distance at high speed, until it manages to turn away.

In the end, missiles optimised for such long-range shots may have a terrible pk and still be very useful to neutralize the threat posed by enemy fighters...

That high temperature aluminium they were talking about might be part of the solution to high speed use...

Good point, that may be useful.

besides I would suggest that an IIR seeker would make rather more sense against potentially stealthy enemy aircraft.... it is passive so will give no warning... just a mach 10 diving missile from 60km altitude....  hehehehe... like a meteor... and I don't mean the European product... I mean the real damn thing....        

I guess it must be quite difficult to keep IR apertures for the seeker cold enough for operation at 10 M!

GarryB wrote:I would think long range missiles would be more effective against lower altitude targets and with tiny control surfaces at very high speed their ability to turn would be improved at lower altitudes, and also coasting along at high altitude lofted trajectories means at the terminal end of the engagement a high altitude target would mean less energy for the missile compared with a high speed diving attack on a target at lower altitudes.

Yes, it is a bit counter-intuitive, but once the missile is coasting the key is drag. From the simulations and analysis that I have seen, in a long shot the missile benefits most from rarefied air, even when it is detrimental to manoeuvring. The reason is as exposed before, that the faster the missile is, the less it needs to turn (in angular terms) and also, the bigger the lift it creates. When the missile dives into dense air, the drag increases massively and the speed normally decreases or can be kept but only with pronounced dive angles. I even saw a simulation where a R-37M lost energy so fast when diving that it simply missed against a fighter-type target that was perfectly within range. This effect increases non-linearly with the reduction in altitude, accordingly to non linear increase in air density.

Ironically I think the lattice fins make more sense with the R-77M than they do with the R-77PD because the PD should still have its motor running during the interception of the target where it might have turned the motor off while coasting to a long range target but still restart the motor for the terminal phase

To an extent yes, because with normal rocket engines the missile receives a boost that increases explosively its speed and therefore a lot of energy is bled through drag early on, while ducted rocket ones like Meteor have way longer burn at lower speeds, which is optimal for energy preservation. This is partially compensated with newer dual-thrust rocket engines (dual-pulse is not so precise a term) with a fast and strong burn followed by a long and soft one, which is very good for range.

In any case, the lattice creates a drag during all the flight of the missile, only to be used in the end game. That is not the best for a long-ranged missile, be it a conventional rocket or ramjet. In fact, the longer the range of the missile, the more energy is bled through such aero arrangements, working against the very logic of using a ramjet engine.

... but while grid fins offer all sorts of advantages like harder turns with less risk of the surfaces stalling and more turning force to allow tighter harder turns... I would expect a ramjet powered missile would also have some form of thrust vectoring nozzle so manouvering hard should not be any real issue and of course because it would use thrust based manouvering then the control surfaces should be minimised to reduce drag and just use fine trimming adjustments of the exhaust nozzle to minimise body drag in the cruise phase to get to the target.

If hard turning was so critical they should maybe take a look at the 9M96 and adapt it for the fighters, even the small version would see its range multiplied once launched from a fighter, and with its gas-dynamic manoeuvring it should be the best, even when admittedly expensive. At 4.5 m, it should be possible to adapt it even for the bays of the Su-57. But as said, the best aid for hitting the target is speed. Short range missiles need very hard turning, because they are comparatively slow (delta to speed of the target is much smaller than in the case of a MRAAM) and traditionally cannot do proper lead pursuit but simply chase the target. Maybe that, together with the probably not-so-impressive thrust available after a long shot, is the reason why they have TVC while Meteor for instance doesn't have it.

From the Russian side we have seen already the following:

- Reports that K-77M abandons lattice fins
- A patent drawing of fins for a R-77-alike missile with a split-fin configuration (should help prevent stall even with big deviations of the control surface, while being much more aerodynamic than the lattice)

As far as I can tell the only reason to stop its development just when it is ready to go is that they realise that with new materials and perhaps new passive sensors and new types of propulsion, that a missile that would not cost much more to make but with an order of magnitude better performance could be made instead... and for all we know it might not just be IIR seeker... it might be some from of photonic radar that is not effected by plasma forming around the nose of the missile...

It would need to be a very good reason...

I don't know, there can be all kind of reasons for this, even very mundane ones  

Does it need to be cold?

If it is too hot, it can prevent the seeker from seeing the target.

There is no reason why the IIR aperture needs to be on the tip of the nose... it could be located further back and perhaps split into four array sensors offering 180 degree forward views so it can look for targets on the way... passively... a tiny computer with the power of a modern cell phone could use a built in IR signature data base of 3D shapes to identify most military targets and threats....

Yes, in the Kinzhal we see the apertures away from the nose tip, where there are spots of zero airspeed that create overheating. But this is a missile against ground/surface targets, in an AAM a solution like the one you propose would be necessary and I think that would be difficult and expensive.

GarryB wrote:
What I find weird is that the lattice controls fold forward for internal carriage in a weapon bay... so having a small fin sticking out while it is folded that can turn with the grid fin while the grid fin is folded could be the best solution... release and launch the missile with the grid fin folded forward using an exposed rear small triangular fin for simple flight control.... as the missile approaches the target if the target is in the centre of view and will not require a hard turn to intercept then keep the grid fin folded. If the target appears to be off to one side then deploy the grid fins and start up a third stage booster rocket motor for terminal attack engagement.

If they manage that in a mechanically simple way, why not?

The R-77M is supposed to have a second stage that can be delayed to further extend flight range and add energy to the interception phase of the attack...

What I heard was that it was dual pulse (dual thrust) for extended range. It is better to reduce max speed in order to minimize effects of drag.

Why not have three stages... fast high energy burn to climb and accelerate and then a low energy long slow burn to counter drag for a long period helping maintaining high speed and therefore good range and then have a high energy small motor to give it a boost of speed and energy for the last few seconds of the engagement to improve its ability to hit the target...

Seems logical, but I have not heard about it. The dual pulse trick is simply done by changing the size of the grain of the propellent, not by additional systems to stop the burn and restart it later. But is clear that weapons get more complicated each time, so maybe in the future the burn is stopped and a part of the propellant is reserved for the end-game. That would complicate things for the defending side on long shots. From an energy point of view, the best use of the fuel would be to fly relatively slow at the beginning (while still fast enough to catch the target) and accelerate in the end, but this in turn extends the time of the engagement and gives your rival more time to react.

But what is too hot... the sensor is already cooled to like 200 degrees below zero Celcius... what is another couple of hundred degrees?

I can't tell you exactly. I know that the aperture's own emission is logically going to blind the seeker if it gets too hot. It probably depends on the emissivity of the material, operation wavelength(s) of the seeker and other aspects, but I have not researched much about it.

GarryB wrote:Solid fuel rockets have very different flight performances depending upon their launch parameters... very simple an R-73 missile might have a range of 40km against a target when launch at high altitude at high speed with a head on target flying at high speed and closing range, but from a hovering helicopter at 100m altitude its range is going to be nothing like that no matter what the target is doing.

Certainly. Some posts ago I linked the RVV-AE range chart for different kind of non-manoeuvering targets, head-on and rear aspect, that gives an idea of what a simplification a range figure is. Accurate calculations are needed to tell if a target can be hit.

Many solid rocket motor powered missiles have layers like a cake where the inner layer is a high power high energy fuel that burns rapidly. Traditionally the fuel burns from the centre outwards rather than from one end to the other like a fuse because that means the remaining fuel acts as the missile wall so the actual missile walls can be made thinner and lighter. The hole down the core of the solid rocket propellent can be a circle or it can be star shaped... a star shaped hole down the centre dramatically increases the surface area for max burn rate and max thrust so a missile launched from an aircraft will accelerate and be able to climb rapidly to improve its range performance. The next layer will be lower energy but burn for much much longer extending range by countering drag and maintaining speed allowing better range performance.

Yes, there are a number of configurations of the channel in the propellant to shape the thrust profile

A good reason for the lofted trajectory is that at lower altitudes the max speed of the missile is lower and any energy lost in climbing is made up at the other end during the descent while the increased flight speed on the way to the target boosts range performance dramatically.

An R-73 that moves at mach 2.5 at high altitude might only get to mach 1.5 at lower altitudes and the higher drag will further reduce range performance... of course if the target is close that might not matter...

Apparently the main difference between AIM-120D and previous versions is guidance logic and loft profile. Using properly the energy available in the fuel is not easy and the range increase due to launches at high altitudes and speeds is impressive:

From an energy point of view the best solution is a scramjet that can determine the throttle setting that gets the best speed at that altitude and for long range targets to climb and accelerate to the optimal speed without burning too much fuel trying to fly faster than the altitude will allow the missile to travel at.

There are a number of technological solutions that would improve the energy performance of AAMs, but air forces limit themselves to relatively inexpensive ones. I am specially curious to see in what direction the industry advances, considering that even very sophisticated long and medium range missiles could be shot down with much cheaper short range or self defence ones.

What fuel is used for ramjet engines ? Isn't kerosene enough or do they need special fuel ?

If kerosene works then it's a nice advantage as the missile can be kept in storage with no limits and be refueled by the operator in the airbase.

Isos wrote:What fuel is used for ramjet engines ? Isn't kerosene enough or do they need special fuel ?

If kerosene works then it's a nice advantage as the missile can be kept in storage with no limits and be refueled by the operator in the airbase.

Meteor uses solid fuel, poor in oxidizer, with a gas generator and a valve to control its flow into a combustion chamber where it is mixed with ram air. The booster is solid as well. So it is a "ramjet" in a sense but it is rather known as solid fuel ducted rocket engine.



Following images are from India's SFDR project, based on Meteor:







http://trishul-trident.blogspot.com/2020/02/re-engineered-meteor-bvraam-on-works.html
http://nmlonline.weebly.com/analysis--review/drdos-precious-project-sfdr-connecting-the-dots

Major contract of the Russian Ministry of Defense for the purchase of R-77-1 air-to-air missiles

As the newspaper Izvestia reported in the material of Anton Lavrov and Roman Kretsul, “Fighter demand: the Aerospace Forces will receive the latest missiles under a record contract. High-precision R-77-1 for medium-range air combat will cost 65 billion rubles,The Russian Ministry of Defense ordered [Tactical Missile Armament Corporation] for Russian fighters the latest R-77-1 air combat missiles worth 65 billion rubles. Sources in the military-industrial complex told Izvestia about this. The record-breaking contract will make it possible to equip all types of VKS fighters with novelties, eliminating the shortage of modern air-to-air ammunition. The active homing head gives the R-77-1 a great advantage over previous models and in terms of characteristics it is not inferior to modern foreign developments, experts say.


Largest delivery

The contract is already in progress and missiles are being delivered under it, the sources added. The R-77-1 medium-range air-to-air missiles were purchased in a modernized version that went through import substitution. Now they will be able to make the most of the powerful airborne radars Su-35 and Su-57. The missile received an updated seeker with additional modes of operation, a universal digital communication bus and revised software. This will allow it to more reliably determine the target, even when using interference.

This contract is the largest known purchase of precision-guided ammunition for Russian aviation. Earlier, the palm was held by the purchase in 2015 of a batch of the same missile model in the amount of 13 billion rubles.

The military department did not name the number of ordered ammunition. But, based on the parameters of export contracts for missiles of this family, the new contract is about several thousand units. They can be used not only on the latest fighters, but also on machines of the 4 ++ generation, which have undergone the modernization of heavy MiG-31BM interceptors, as well as on Su-34 fighter-bombers.

Medium-range air-to-air missiles of the R-27 family, which are armed with Russian fighters, are long overdue to change, believes Honored Test Pilot, Hero of Russia Igor Malikov.

- They are good, I have launched a lot of them, but now the planes are equipped with modern digital equipment, and the R-27 missiles are analog. The new ammunition is designed according to the “fire and forget” principle. I have located a target, launched a rocket and can turn my attention to others. And before it was necessary to "highlight" the target for a long time with your locator. An ordinary R-27 flies to a “speck” that is reflected from an object, ”he explained.

With the new missile, the coordinates of the target are transmitted to the software. After the launch, it independently goes to the programmed point and, about 30 km before the target, turns on its own radar station, it itself determines which direction to attack from, Igor Malikov said.

- Such ammunition significantly increases the effectiveness of our fighters. In terms of its capabilities, the R-77-1 corresponds to similar American developments, the expert concluded.

REFERENCE "Izvestiya"

The R-77-1 missile, also known under the export name RVV-SD, is intended for medium-range air battles, when opponents do not even see each other. With its help, you can destroy a target at a distance of 110 km. It is suitable for destroying aircraft, helicopters and cruise missiles, including those made using stealth technologies.

Missile failure

Russian military aviation is just beginning to receive massively missiles with active homing heads. So far, the fighters are using semi-active guided P-27 ammunition. Even in Syria, the planes initially went with these obsolete Soviet models. In video frames and photographs from the Khmeimim airbase, the new R-77-1 rarely appeared.

The original version of the R-77 was developed in the late 1980s as a response to the American AIM-120 AMRAAM medium-range air-to-air missile. It was planned to serially produce it at the Ukrainian enterprise "Artem". But after the collapse of the USSR, it was not possible to establish production.

Limited batches of R-77 were assembled in the Russian Federation at the pilot production facility of their developer, the Vympel State Design Bureau, in cooperation with Ukrainian enterprises. The novelty under the export designation RVV-SD [actually RVV-AE] was eagerly purchased by traditional buyers of Russian weapons. China and India received the most. At the same time, these missiles were not supplied to the Russian Air Force. Only in 2009, a small number of them were purchased for the Su-35S fighters, which were then being tested.

The severing of ties with Ukrainian factories after 2014 forced the search for Russian alternatives to the rocket components. According to Boris Obnosov, head of the Tactical Missile Armament Corporation, large-scale work had to be carried out on import substitution and localization of its production. In the version using only Russian components, the ammunition received the designation R-77-1.

The production of seeker heads - the most complex element of the rocket - was launched at the Agat enterprise near Moscow. In parallel, it was improved by adding new operating modes and changing the software.

A complete transfer of production to Russia made it possible to order the first mass batch in 2015. The new, even more ambitious contract for the supply of advanced missiles is several times more expensive than the previous one.


Bmpd's comment. Active radar homing heads for R-77 missiles of all modifications (R-77, RVV-AE, R-77-1) were developed and manufactured by the Agat Research Institute (Moscow) from the very beginning. The R-77-1 rocket (product 170-1), as a further development of the R-77, was developed by the Vympel GosMKB (now part of the Tactical Missile Armament Corporation - KTRV) since the 1990s, the stage of the State joint missile tests was formally opened in 2006, although in fact tests were only started at the end of 2010. Serial production of the R-77-1 was launched by KTRV in 2013.

https://bmpd.livejournal.com/4122588.html

Rob Lee
@RALee85
·
12h
The MoD signed its largest aerial PGM contract worth 65 billion rubles for "several thousand" R-77-1 medium-range AAM with upgraded seekers. They can be used by Su-57, Su-35S, MiG-31BM, and Su-34 aircraft and their Ukrainian components were replaced. 179/

Isos wrote:
Rob Lee
@RALee85
·
12h
The MoD signed its largest aerial PGM contract worth 65 billion rubles for "several thousand" R-77-1 medium-range AAM with upgraded seekers. They can be used by Su-57, Su-35S, MiG-31BM, and Su-34 aircraft and their Ukrainian components were replaced. 179/

How will they upgrade the seeker of the R-771-1? Active radar seekers haven't witnessed much improvements anywhere.

They already have developed AESA seekers for the r-77 serie.

Isos wrote:They already have developed AESA seekers for the r-77 serie.

Meaning the R-77-1 in service with the Russian Air Force are not sporting an AESA radar?

AESA on a fighter jet is far more useful than having one in an air to air missile.

RTN wrote:Meaning the R-77-1 in service with the Russian Air Force are not sporting an AESA radar?

AESA on a fighter jet is far more useful than having one in an air to air missile.

The argument given for the AESA AAM seeker is that it makes it harder for the target to scape the seeker's field of regard in a situation of high closing in speeds / big relative angular displacements, due to the agility of electronic instead of mechanical scan.