Russia and other developments in Hypersonic Research

Jet engines are pretty standard on most subsonic large aircraft like airliners and cargo transport planes... a more efficient much cheaper simpler engine design is always interesting and potentially useful... and of course if this offers potential for scramjet propulsion having an engine type that can operate from a standing still start to mach 20 plus in the high atmosphere would mean the goal of an aircraft that could take off from a runway and accelerate fast enough to launch a satellite into orbit could be achieved...

Currently you need a significant rocket from something like a MiG-31 to get something in to low earth orbit but imagine an aircraft that climbed to 60km altitude at mach 20... you are well above most of the atmosphere so a rocket could then take a sizable payload into low earth orbit or a smaller payload to a much higher orbit without needing to be enormous and therefore expensive...

That plane could also deliver things around the world at astounding speeds... whether it is humans or critical cargo.... imagine a 3 hour flight from London to Sydney...

For the same reason they need more than one type of jet engine... a cruise missile and a reentering ICBM or SLBM RV and an interceptor aircraft and a bomber aircraft and a long range passenger plane are not all going to be able to use the same scramjet.... different sizes, different speeds, different altitudes and expectations etc etc...

dino00 wrote:Why would a institute that almost exclusively develops ICBM/SLBM needs a scramjet?

#1 Scram-jet powered HGV.

#2 Scram-jet powered upper stage that cruises thru the upper atmosphere instead of going ballistic high above the earth. Think of it as a high-altitude long-range version of Zircon launched by a rocket stage.

There are just SO many delicious uses for such technologies, none of them appealing to the Uh'murikkkan elites.

Well previously if you wanted intercontinental range you needed to reach orbit and to reach orbital speed you could only do so with a rocket... even a ramjet couldn't get you fast enough.

But now a scramjet can do the job and normally in a rocket motor the fuel by weight is one quarter fuel and three quarters dedicated to generating enormous amounts of oxygen for that fuel to burn rapidly.

For something like an ICBM or SLBM 95% of the vehicle is fuel by weight, so a 100 ton missile has about 25 tons of actual fuel and 75 tons of oxidiser so that fuel can be burned.... but it needs the enormous and powerful rocket engine it uses because it needs to carry all that fuel... so if you replace that rocket engine with a scramjet engine you need a quarter of the fuel by weight which means you dramatically reduce the weigh of the vehicle so you can use a much less powerful scramjet motor to move it.

A nuclear ramjet does not involve combustion so it is technically a scramjet anyway because the airflow does not need to be slowed down like in a ramjet... there were plenty of old designs of super long range cruise missiles that were going to use ramjet motors to fly intercontinental distances inside the atmosphere... but at nothing like orbital speeds... something like the the original BURAN or Burya...

https://en.wikipedia.org/wiki/RSS-40_Buran

https://en.wikipedia.org/wiki/Burya

Both projects before ICBMs were perfected and reliable... both were mach 3-3.5 ramjet powered cruise missiles launched by solid rocket boosters.

With scramjet motors their speed and range could be tripled these days, while their weights could be reduced by an enormous amount too with much better rocket and scramjet propulsion... and of course much lighter heat resistant structures and lighter nuclear payloads.

So it sounds like they are making a scramjet powered Hermes missile... presumably a full calibre model where the missile stage has a scramjet motor presumably with an integral solid rocket motor of the combined rocket ramjet design that they have been using.

So it still has a rocket stage booster that launches it, but I suspect its size and shape and drag will change.

Right now with the 100km range Hermes it has a huge solid rocket booster to get it up to 1.3km/s speeds but the second stage... the actual missile is a very slim low drag section that pretty much coasts to the target over a lofted trajectory to 100km range targets.

This version would need to be thicker for the scramjet and fuel, but would need rather less solid rocket assistance... first of all because as I mentioned it wont need to be accelerated to 1.3km/s because with the front section having a scramjet motor it can further accelerate and climb much more efficiently than any rocket, so a smaller lighter solid rocket separate booster which then falls away and then a solid rocket booster inside the scramjet to further accelerate the missile and then light up the scramjet to accelerate to very high mach.

The standard Hermes reaches 1.3km/s which is about mach 4 or so, but they should be able to accelerate to about 1.8km/s or so quite easily... but the point is that it will be 1.8km/s powered flight.

It is also interesting that aircraft can carry Hermes and use it in an air to air role/mode...

Hate to sound clueless but I am assuming the 100km Hermes is 3.5 meters in length and 170mm in diameter, and regarding the weigh characteristics of the new missile it should not be that much different in dimensions but better speed and range?

GarryB

It's a ramjet, that can go Mach5, it will not change the diameter.

You are right and wrong... the missile stage of the Hermes is long and thin to minimise drag so that after the booster stage falls away it can fly ballisticly towards the target on a trajectory like an artillery shell maintaining speed because it is essentially a dart.

It will be a ramjet, though later on if they want to extend range much further they will have to fly rather faster which would require a change to a scramjet...

The point is that to make a ramjet effective it needs an intake and a ramjet engine and of course fuel and it mentions the payload has almost doubled to 57kgs.

Now the original Hermes has a 29kg warhead, but in a small slim dart the mass was useful because it helps it fly through the air more efficiently...

Imagine trying to throw a blown up balloon... its light weight means you can accelerate it quickly but its huge drag and lack of weight (ie momentum) means it slows down just as rapidly.

In comparison a small ball bearing can be thrown great distances.

We know this new Hermes missile has propulsion... when fired horizontally and presumably with a much smaller solid rocket booster fired from helicopters it reaches 25km, but from a ground launcher presumably angled up and fired like an artillery shell it can hit targets 100km away.

A new model with a ramjet engine will have its own power so it does not need to be a tiny slim dart... a thicker body means more room for fuel, and because the warhead has doubled in size you are going to need that extra fuel to carry it any useful distance.

From the article it sounds like it will be using high speed and also manouver capability to evade enemy air defences so lots of fuel would be useful, while the bigger warhead will make it more effective on impact.

It says the weapon is 150kgs in the launch tube that includes the main missile and the booster... with a larger body and a ramjet it would no longer need to be accelerated to 1.3km per second so the smaller solid rocket booster could be used meaning less weight in the solid rocket portion and more weight can be put into the missile itself as warhead and fuel...

What is really interesting would be SOSNA-R... or Pine... currently a small light dart missile on a solid rocket booster designed to shoot down aircraft to replace the SA-13 and SA-9... because of the solid rocket booster which accelerates the light small missile to about 1.3km/s the weapons flight time to 10km is about 12 seconds... imagine a scramjet powered model with a core of DU 1.5m long and 15kgs in weight that could be directed at a tank at 3km/s... able to hit targets between 15 and 35km away... with a flight time of 8-15 seconds or so...

Hate to sound clueless but I am assuming the 100km Hermes is 3.5 meters in length and 170mm in diameter, and regarding the weigh characteristics of the new missile it should not be that much different in dimensions but better speed and range?

The addition of an engine on the missile will mean the missile will need to be bigger but that the solid rocket booster can be smaller and lighter.

The solid rocket booster as mentioned is a 207mm item and with propulsion the front section might as well fill the tube to add fuel and warhead... the ramjet could be designed to equal drag in terms of thrust most of the way... so essentially the solid rocket will accelerate the missile to flight speed... a smaller rocket might only manage 800m/s with a bigger heavier missile payload but the ramjet should be able to accelerate the missile to 1.3km/s and then throttle back and just maintain that speed to target... maybe increase thrust near the target where manouvers would otherwise slow it down a little...

This is neat...

The addition of an engine on the missile will mean the missile will need to be bigger but that the solid rocket booster can be smaller and lighter.

Hermes well the 100km version has two stage engines. https://web.archive.org/web/20100213044513/http://kbptula.ru/eng/multi/hermes.htm Really happy I found this old info. However I suddenly got an erection from this part of dino00's article. "The caliber of 207 mm taken from "Hermes" will not change either." if you click on that image 100km Hermes missile is used with a 3.5 meter length tube and 210mm caliber. So if the ramjet which of course will be the 2nd stage engine will mean that length wise it would be longer with a little more weight because article did say same caliber with folding wings so by bigger you mean longer length?

Although I personally think it will be the same length or close to it since Hermes warhead was 28kg this one says 57kg warhead hermes with warhead included is 130kg add additional 29kg to match new ramjet missile than its over 150kg(this is there reference for new missile weight) by 9kg. 7000km/hr to km/s is 1.944 times the 40 seconds in dinos article that it accelerates with such speeds meaning 77.76km range covered. but of course additional range is also covered by the booster and the ramjet setting itself to get to 7000km/hr than lasting 40 seconds with it. https://web.archive.org/web/20100309083505/http://www.kbptula.ru/eng/multi/hermesk.htm and https://web.archive.org/web/20100309095842/http://www.kbptula.ru/eng/multi/hermesa.htm Hermes 170mm booster and warhead is for 1 20km. Hermes 207mm with warhead being 20kg heavier is up to 100km. So I am guessing that 80km + 77km means it will cover a 157km range? Although I have no idea how much booster or sustainer ranges last but I do know with slightly bigger diameters like 207 instead of 170 gave it that 80km boost(assuming sustainer stages are same sizes for both) while the article stated 77.76kms of 7000km/hr for 40 seconds.

Hermes well the 100km version has two stage engines.

No. That is not true.

As far as I can work out the Hermes missile is a two stage missile but the second stage does not have an engine at the moment... There is the solid rocket booster to get the missile up to a speed of 1.3km/s and then a small light narrow low drag coasting stage that is not powered or perhaps has a gas bleed motor that just overcomes or reduces drag in flight.

When fired from a ground vehicle it is angled upwards and lofted towards the target in a fully ballistic trajectory.

When fired horizontally from a helicopter its range is closer to 15-20km

If you look at this current page:

http://www.kbptula.ru/en/productions/multi-service-weapon-systems/germes-a

Note to the right of the image of the helicopter there is a list headed System composition.
Click on the link Containerised Hermes guided missile and it will bring up a small box with the detailed information about the helicopter launched missile.

You will see the missile is smaller... the ground launched missile has a 210mm calibre booster that accelerates the missile to 1.3km/s, while the helicopter launched mode the booster is 170mm calibre and accelerates the missile to 1km per second and is fired more directly at the target... it is a bit like the difference between a tank gun firing at targets 3-5km away and an artillery piece using the similar ammo over much greater ranges lofted into the air.

In both cases the missile is a 130mm calibre missile with a warhead of about 30kgs.

The coasting stage needs to be light so the actual coasting stage will not be much heavier than the warhead... I have seen listings showing the second stage has a 27kg HE warhead and the entire second stage component is 30kgs... which is damn impressive.

The ground launched missile is 130kgs in the launch container and the helicopter or aircraft launched missile is 110kgs in the launch container... so the difference is 20kgs of solid rocket fuel in the different sized solid rocket boosters.

[quote]"The caliber of 207 mm taken from "Hermes" will not change either." if you click on that image 100km Hermes missile is used with a 3.5 meter length tube and 210mm caliber. So if the ramjet which of course will be the 2nd stage engine will mean that length wise it would be longer with a little more weight because article did say same caliber with folding wings so by bigger you mean longer length?[quote]

The article is about a new version of Hermes where the second stage has a proper ramjet sustainer engine... where before it either had nothing or a very low thrust gas bleed rocket motor to overcome drag... if the stage was sitting on the ground and this rocket was running it wouldn't actually move the rocket, but when the missile is flying through the air the low thrust rocket greatly reduces the drag of the rocket in flight so it maintains its high flight speed for much much longer... they could put a high energy rocket in there but it would only burn for a few seconds and only increase speed a little and then when it burned out the missile would rapidly slow down because drag is increased by increased speed. By using a very low thrust rocket motor the motor can burn for several minutes, and while it wont speed the missile up in flight it will make it retain speed much better which means it will travel much further by travelling faster.

This is used in artillery shells where a low power rocket motor is located in the rear of the shell and it blows gas out the back of the shell in flight to reduce drag... it is called base bleed in artillery shells and greatly increases range by helping the projectile to maintain a higher speed.

All your calculations are interesting, but the original Hermes... either with no engine in the second stage or a base bleed rocket motor in the second stage relied on a big heavy solid rocket booster for its flight range. The ground launched one got extra range by being lofted into the air up to thinner colder air at altitude where drag is less and the missile can fly faster with lower drag, while the aircraft launched model seems to be launched directly towards a target... remember that information about that new missile for the Mi-28NM that had a 25km+ range and used an IIR seeker and datalink turned out to be Hermes...

Well this is talking about adding a ramjet motor to the second stage... now a ramjet motor is flexible.... you can operate it in low thrust to counter drag and it would be much more efficient than any base bleed rocket motor because it is scooping up air as it moves so even a very small fuel burn will generate useful levels of thrust to maintain speed over enormous distances... and you can increase throttle to climb to thinner colder air where the missile can move faster because of lower drag.

The point is that the missile probably needs to move at between 1km/s and 1.3km per second to reach the different ranges it reaches, but with having a ramjet there you can use fuel to accelerate to and maintain those speeds much more efficiently than using solid fuel.

A solid fuel by weight is three quarters oxygen production and one quarter fuel to burn in that oxygen.

So say the solid fuelled rockets weight 70kgs and 90kgs, and the final stage missiles would therefore weigh  40kgs for the air launched model and the ground launched missile would also be 40kgs because they are the same missile.

So the shorter direct fire air launched missile (170mm calibre) is 70kgs + 40kgs = 110kgs, and the ground launched missile (210mm) is 90kgs + 40kgs = 130kgs.

Both 40kg missiles are 130mm calibre, but the launch tube calibres are determined by the solid rocket booster sections... both tubes are 3.5m long.

This new missile they are talking about... the missile stage will be heavier and larger calibre because it does not need to be a narrow low drag dart... it has its own motor and fuel and does not need to be accelerated to top speed by the solid rocket booster.

It is clear they are using the 210mm calibre... and they say they will use the ground launched Hermes bigger 90kg 210mm calibre booster rocket motor, so the tube will be 210mm so it would make sense to use that space for the second stage... they mentioned the weight of the new missile will not exceed 150kgs, so that means the new missile will weigh 60kgs... but with a 57kg HE warhead we have a problem...

The thing is that with a ramjet motor in the missile, they don't need the full length full power solid rocket booster as used in the ground launched model... in fact I would argue that they could halve its length and weight to perhaps 45kgs and still get enough thrust to accelerate the second stage to a useful speed and distance where its ramjet could take over...

90kgs of solid rocket fuel means about 68kgs of material that just generates oxygen, with the remaining 22kgs being actual fuel burned in that oxygen rich environment.

Cut it to 45kgs of solid rocket fuel and that means 34kgs of oxygen generating material and 11kgs of fuel, but it means you can then carry 45kgs of ramjet motor and fuel and guidance equipment.... say 2kgs for the ramjet motor itself... which is mostly titanium to resist the heat and empty space... another 15kgs of guidance stuff including control surfaces and motors, which leave 28kgs of fuel...  which means it carries 39kgs of actual fuel and for the solid rocket motor it carries 34kgs of oxygen generating material, but with 28kgs of ramjet fuel and it will scoop up the 49kgs of Oxygen to burn that fuel in flight.

Most importantly it has energy management... it can climb to altitude and coast in a low engine thrust setting maintaining speed all the way and then a full throttle dive on the target.

But why are they doing this?

The key is the ramjet motor... they don't want a simple artillery shell type missile that is lofted towards the distant target and basically finds its target as it falls and then steers straight into that.

They want a high speed manouvering target that is difficult to shoot down so they need an engine on the second stage.

When it reaches its target area it does not matter if it left the tube and accelerated to 800m/s at solid rocket booster burn out or 1,300m/s... because it has a ramjet motor and can then climb and accelerate to much higher speeds if it needs to...

With the older missile the faster it was fired the more energy it had to reach the target, but with a ramjet motor it can use the fuel much more efficiently and effectively.

Nice development.

The only thing that made me sad(it was expected to happen anyway) is the timeframe of the missile, I was at least hoping in the mid-2020s instead of beginning 2030s to enter armed forces. I am assuming the Su-70 as shown by paralays drawings before has the same 1 meter width by 4.6 meter length weapon bay as the Su-57. So can we fit 8 of those fuckers in there if we were to give it an air to ground role?  

With exhaust thrust vectoring control it will only require fixed stabiliser fins but also be able to pull amazingly hard manouvers in flight... which would be valuable because it is supposed to get the ramjet motor to enable it to evade enemy air defence systems...

Edit... a 2030 timescale is interesting.... they clearly think that in 10 years time HATO will have developed some sort of short range IADS to protect their forces and this is the solution to defeat them.

Until then of course they will have standard Hermes missiles hitting targets out to 100km so it will be worth the wait.