New Russian heavy ICBM - Sarmatian

No. Because their engineers figured it was necessary. Liquid fuel is apparently harder to work with.

Their experience with solid fuel is lot longer than most.

So I trust their choice.

Solid fuel does not allow for throttling whereas liquid fuel does. This obviously has advantages including for rocket control and guidance.

Sarmat will be vurnerable to boost phase interception. This missile use liquid fuel and has longer boost phase than modern solid propellant ICBM and SLBM. Event China new heavy ICBM DF-41 use solid propellant.

Actually the opposite is true.

Liquid fuels are more powerful than solid fuels and so should offer shorter burn periods.

Also the threat of boost phase interception is zero... there will be no ABLs flying within 1,000km of any Russian ICBM base at the time of launch so that problem does not exist in reality.

Russia develop liquid fuel ICBM becouse has a problem with technology for solid heavy ICBM? Sarmat will be cheaper and quickly come to be armed.

Liquid fuels are more powerful and cheaper than solid fuels.

They are storable liquids so the missile can be ready to launch at any time without needing to be loaded with fuel.

Liquid fuel can be pumped through the engine exhaust nozzles to cool them and to preheat the fuel... the hotter you can get it the more energetic it is when combusted.

There are new technologies that include pulse detonation... is has been found that the first ignition impulse generates a spike in power... further work on that could lead to an increase in power simply by pulsing the fuel to increase energy.

Boost Phase R-36M2 is about 5 minut. Boost phase Topol M < 3 min...

Duh... put the weight of an R-36M2 on a Topol M rocket engine and it wont even get off the ground.

The difference is mainly total mass, not engine efficiency.

Not that it is relevant anyway... who cares about boost phase? What are the US going to do... send snipers to shoot down Russian ICBMs using Barret sniper rifles... or are you going to fly a 747 with a big laser within 200km of Russian ICBM fields and have them orbit the area waiting for launch time...

That is just silly.

Arrow wrote:Sarmat will be vurnerable to boost phase interception. This missile use liquid fuel and has longer boost phase than modern solid propellant ICBM and SLBM. Event China new heavy ICBM DF-41 use solid propellant.

Sameone using the world"modern" and "solid fuel" in the same sentence ?
: o


The solid fuel is primitive and inefficient solution, cheap to implement and doesn't require too much understanding.


for the same weight it is way less efficient,and it become very hard to scale above certain size.

It advantage due to the heavy rocket body in certain situations, mainly if the rocket has to be tilted, lifted erected, or shoot from underwater.
But the throw weight of it is limited.

Check the space shuttle boosters.
Those are scaled up US ICBMs.

For the US the solid rocket is a better option in many cases as they have invested a lot of money to make them more efficient and more powerful than their liquid propellent rockets.

For the Russians the liquid propellent rockets are cheaper, more powerful, can be stored for very long periods and can be unloaded from a rocket if you need to transport it anywhere.

The solid rocket boosters on the Space Shuttle are enormously expensive and once started cannot be stopped or throttled.

Solid rocket motors are not bad as such, but are claimed in the west to be "safer" than liquid propellent rockets.

the irony is that the only case of an accident loading a SLBM in the soviet union was with the solid propellent SS-N-20 which was dropped onto the side of an Akula sub (ie NATO codename Typhoon class SSBN). The fire damage led to that particular vessel to get the nickname Red October...

The simple fact is that it is much easier and cheaper to put an empty liquid fuel rocket into a sub launch tube and then pump the fuel into the missile while it is in place...

The liquid propellents can remain in the missile for the entire voyage of the vessel so no problems like with cryogenic liquid fuels or non storable liquids where there is an enormous delay for launch while the missile is fuelled before launch.

the advantage of the solid rocket is simple : Cheap.

Disadvantage:
-unsafe
-heavy (compared to the true mass)
-impossible to use certain tasks
-not possible to change the thrust
-hard to vector it
-has to be assembled in segments


The best solid rocket exhaust speed is 2300 m/sec, the worst liquid is 3300 m/sec ( best around 4500 m/sec).

It means that V[rocket final speed] = V[exhaust speed]* ln(m[full mass]/m[empty mass])

Means if the empty rocket 10 tons , the full is 74 tons, then the solid will accelerate to 4600 m/sec, the liquid will accelerate to 6600 m/sec .


The additional problem is the solid rocket empty mass higher than the liquid one, because the full rocket body is the combustion chamber.

Example the Shuttle booster has an empty weight of 100 tons, full 700. The Soyuz first stage has 44 vs 4.


Reason why the SzU started to make solid boosters is the advance of composites.

Due to the above the SzU/Russian SSBNs either smaller for the same warhead capacity, or can have more warhead for the same tonnage.

No. Solid rocket fuel is not cheap. It is actually rather expensive.

The real problem with the discussion about solid vs liquid is that most supporters of solid... ie the west think that liquid propellent is still in the dark ages and cannot be stored in the weapon.

In such a comparison the solid fuel rocket is better because it is always ready for use and handling of liquid propellents can be hazardous... and of course the loading period means a long delay if you want to fire an unfuelled missile.

Liquid fuel rockets need pumps and tubes to move fuel, and tanks to store fuel components apart inside the weapon.

Solid fuel rockets used to need strong external structures and burned from one end to the other with the lower area needing to be strong enough to support the heat and pressure of the rocket fuel as it burned.

Newer designs burn from the centre out so the burning fuel is supported by the remaining fuel outside it as it burns with the structure outside of that.

The R-73 is an air to air missile with solid rocket fuel and entered service in the 1980s. It had trim vanes mounted inside the engine exhaust to deflect the thrust to allow very energetic manouvers upon launch, so thrust vectoring is possible with solid fuel rockets... even just an external control surface could be used to steer the missile if needed.

ICBMs are filled with storable liquids that can remain in the missile for years at a time without maintainence.

Space rockets tend to not be fuelled until the rocket is near ready for launch and I suspect western "experts" are thinking of such rockets when they think about liquid propelled rockets.

Acceleration is power to weight ratio... it is not a solid vs liquid debate.

GarryB wrote:No. Solid rocket fuel is not cheap. It is actually rather expensive.

Compared to a ford focus it is expensive. Compared to a similar mass liquid rocket it is cheap.

GarryB wrote:
The real problem with the discussion about solid vs liquid is that most supporters of solid... ie the west think that liquid propellent is still in the dark ages and cannot be stored in the weapon.

No, the real problem is the liquid fuel require sophisticated turbine, pumps and engine.
Solid doesn't.
Anyone saying that a 40 tons liquid rocket is primitive compared to the solid doesn't know anything about the basic physic.

GarryB wrote:

In such a comparison the solid fuel rocket is better because it is always ready for use and handling of liquid propellents can be hazardous... and of course the loading period means a long delay if you want to fire an unfuelled missile.

Liquid fuel rockets need pumps and tubes to move fuel, and tanks to store fuel components apart inside the weapon.

Solid fuel rockets used to need strong external structures and burned from one end to the other with the lower area needing to be strong enough to support the heat and pressure of the rocket fuel as it burned.

Newer designs burn from the centre out so the burning fuel is supported by the remaining fuel outside it as it burns with the structure outside of that.

Only the most primitive, firework rocket burning from the end.

All solid rocket manufactured with centrifuge propellant moulding.

The casing has to be strong enough to withstand the pressure, considering that the highest pressure will be at the end of the burning, when the thickness of the remaining propelant is zero.
Additional any material that increase the structural strength of the propellant automatically decreasing the efficiency and final speed of the rocket.

GarryB wrote:
The R-73 is an air to air missile with solid rocket fuel and entered service in the 1980s. It had trim vanes mounted inside the engine exhaust to deflect the thrust to allow very energetic manouvers upon launch, so thrust vectoring is possible with solid fuel rockets... even just an external control surface could be used to steer the missile if needed.

ICBMs are filled with storable liquids that can remain in the missile for years at a time without maintainence.

Space rockets tend to not be fuelled until the rocket is near ready for launch and I suspect western "experts" are thinking of such rockets when they think about liquid propelled rockets.

You deflecting the flow, in the case of the liquid you move the engine itself.

Obviously the second is more effective, and the first require more material and mass.

GarryB wrote:
Acceleration is power to weight ratio... it is not a solid vs liquid debate.

No.



E=0.5*m*v*v
Means if the power is the same, but the exhaust speed is half, then the exhaust mass can be four times more.

The solid vs liquid problem is simple.

The liquid rocket is nothing else just a metal tube, that you fill up in a centrifuge with solid monopropellant.
If you want double thrust then just double the length of the pipe, and increase the diameter of the nozzle.
But of course the wall has to be strong enough to withstand the pressure.
Additional problem is because it is propellent, you need filling material to slow the burning ,and that decreasing the efficiency .
But the wall of the rocket (the tube) insulated by the propellant from the heat of combustion.

The liquid is different animal.

The fuel tank is simple thin metal.
But , the pumping of the liquid into the combustion chamber require high pressure and flow, means you need a gas turbine, two turbopump and a high temperature pressure chamber with cooling.
And if you want twice thrust then you need two times bigger from everything.
It is way more expensive and complicated than the primitive solid rocket.

The liquid rocket is nothing else just a metal tube, that you fill up in a centrifuge with solid monopropellant.
If you want double thrust then just double the length of the pipe, and increase the diameter of the nozzle.
But of course the wall has to be strong enough to withstand the pressure.
Additional problem is because it is propellent, you need filling material to slow the burning ,and that decreasing the efficiency .
But the wall of the rocket (the tube) insulated by the propellant from the heat of combustion.

The liquid is different animal.

The fuel tank is simple thin metal.
But , the pumping of the liquid into the combustion chamber require high pressure and flow, means you need a gas turbine, two turbopump and a high temperature pressure chamber with cooling.
And if you want twice thrust then you need two times bigger from everything.
It is way more expensive and complicated than the primitive solid rocket.

I think you mean:

The solid rocket is nothing else just a metal tube, that you fill up in a centrifuge with solid monopropellant.
If you want double thrust then just double the length of the pipe, and increase the diameter of the nozzle.
But of course the wall has to be strong enough to withstand the pressure.
Additional problem is because it is propellent, you need filling material to slow the burning ,and that decreasing the efficiency .
But the wall of the rocket (the tube) insulated by the propellant from the heat of combustion.

The liquid is different animal.

The fuel tank is simple thin metal.
But , the pumping of the liquid into the combustion chamber require high pressure and flow, means you need a gas turbine, two turbopump and a high temperature pressure chamber with cooling.
And if you want twice thrust then you need two times bigger from everything.
It is way more expensive and complicated than the primitive solid rocket.

A Liquid rocket usually requires several separate tanks and has the advantage of allowing variable throttle settings. On some models cryogenic fuels can be pumped through rocket nozzles for cooling purposes (cooling the engine components and pre heating the fuel which makes it more efficient).

When a solid rocket starts you cannot stop it or even turn it down.

Most solid rocket AAMs had dual burn propellents... an initial high energy fuel to rapidly accelerate the missile to high speed and a lower energy fuel that maintains speed and increases range.

For those not familiar a high energy fuel burns rapidly and gives max thrust but often longer range can be achieved by using lower energy fuel too.

As an example a missile like the R-27ET has a flight speed of about mach 4.5, but it is a long range missile. If you load it with all high energy fuel you might get a mach 4.8 top speed but all the fuel will be burnt up rapidly and then it will coast to the target so its range might be 30-40km. If you take out half of that high energy fuel and use lower energy fuel that helps it maintain speed but burns for 10 or 20 times longer than the high energy fuel the missile wont reach as high a speed but will maintain speed for much much longer which means it will travel much much further.

Rocket motors offer a top speed depending upon the altitude of launch, so an R-27ET launched at low altitude might only reach mach 2 and instead of hitting target 60km away like it can from a high altitude launch from low altitude it might only hit targets at 20km... but then the effective range of a sidewinder at low altitude is about 5-8km so it is still a useful missile.

The point is that ramjet and scramjet powered missiles can be throttled to give max speed without wasting fuel... imagine driving a car with your foot flat on the accelerator pedal all the time... being able to add power to accelerate and then ease back for cruising speed and then use more power if you come to a hill or whatever.

Of course sometimes liquid fuel is not the best... the fuel used in the Kh-22M was very toxic and not very popular with the crews that had to load the fuel and weapons... but in terms of performance there were no solid fuel equivalents...

The profiling of the acceleration is an interesting topics.

requiring same clever calculations to make the most optimal burning profile : )

Example, the space rockets needs to accelerate fast, but if they accelerate in too early then they loose energy due to air drag.

The kerosene contain more than 30 Mj/kg energy, the best explosive contain around 5Mj.

Of course the kerosene require oxigen, every kg require 3.42 kg (theoretical minimum ) .

Means an air breathing aircraft range 5-6 times more time than a rocket.

Problem is as the aircraft accelerating the incoming air energy increase as well.

Around 3 match the air will have 0.5 Mj/kg energy, means the required air to burn one kg of fuel will contain 8.5 Mj of energy ( 3.42*5*0,5).


Means an air breathing engine can't work with turbine above 2 match.
And actually above 6 match the airflow in the engine must be supersonic.

Positive is between 2-6 match you don't need moving parts in the engine. : )


Means if you using air breathing engine to achieve match 2-6 then it need bypass and dual mode turbine+ramjet engine, OR rocket booster + ramjet.

Scramjet solves those issues...

GarryB wrote:Scramjet solves those issues...

Scramjet means that the air flowing in the engine by supersonic speed.

So the combustion has to be fast enough to expand the gas to generate thrust.


And it is a bit hard to calculate/design/make experiments. : )

Yes... so unlike with a normal turbojet or turbofan engine the intake air does not have to be slowed to subsonic speeds before going through the jet engine.

With a medium bypass turbofan engine the aircraft can take off normally from a runway but as it accelerates the air going through the engine can be greatly reduced while the air going around the engine... the bypass air flow can be increased and can generate the primary flow of thrust generating air.

At hypersonic speed up to orbital speed all the air flow can be bypass air with none going through the engine.... a scramjet being an air breathing rocket...

GarryB wrote:Yes... so unlike with a normal turbojet or turbofan engine the intake air does not have to be slowed to subsonic speeds before going through the jet engine.

With a medium bypass turbofan engine the aircraft can take off normally from a runway but as it accelerates the air going through the engine can be greatly reduced while the air going around the engine... the bypass air flow can be increased and can generate the primary flow of thrust generating air.

At hypersonic speed up to orbital speed all the air flow can be bypass air with none going through the engine.... a scramjet being an air breathing rocket...

Not that easy , as I remember the kerosene should be good up to 8 match, above that you need hydrogen.
but H2 bulky, only 70kg/cbm.

Additionally the flow and reaction speed of the fuel critical as well. High pressure fuel pump(few thousand bar? ) and/or pre-heater.

So you need to increase the density of H2 and you need to preheat... and you also need to deal with friction heating of the aircraft... so slush hydrogen pumped through the skin of the aircraft to cool the skin and preheat the fuel...

Arrow wrote:Sarmat program trouble ?

http://russianforces.org/blog/2017/01/is_sarmat_program_in_trouble.shtml

.shtml - source with .shtml extension should be not trusted as their engineering is not strong with them xD

Arrow wrote:Sarmat program trouble ?

http://russianforces.org/blog/2017/01/is_sarmat_program_in_trouble.shtml

Podvig is a well known liberast. So basically a one-note-Johnny about how Russia is failing on every front.
Development delays = Program failure in the minds of these hater morons.

It is tiresome to listen to blogger "experts" yap about delays. Any engineering that requires new and original
solutions cannot be project planned like routine, predictable activity. So the project plan has to be revised
at various stages to deal with the reality of problem solving. Project delays can and do occur because of both
endogenous and exogenous shocks.

Trying to paint Russia as some collection of chimps who can't weld a joint in 2017 is pure, unadulterated retardation
even if it is with malicious intent. If Russia can develop the Angara it can develop an SS-18 replacement. I suspect
they are having issues with the recessed engine design where the vertical length between the engines and the fuel tank
is reduced. This is not a normal design choice and there are likely both heat and vibration problems that they have to
solve.

His conclusion at end isn't backed up by anything other than a hunch and not what the def min stated.

miketheterrible wrote:His conclusion at end isn't backed up by anything other than a hunch and not what the def min stated.

Pavel seems to be trolling lately.

Pavel is lost cause , He keeps making sensational claims in between to get his funding from CIA to prove he knows something.

He said last time Rail mobile system got cancelled due to Economic Crisis and now Saramat !

Pretty much. I called him out on it after the test of the rail icbm system and he just told me to delete my account. He is a god damn loser and knows squat. All he does is repeat other news and adds his own spin. The rail system is going to be operational in 2019.

Went on that site yesterday to look around and afterwards actually went checking to see where he was living today. Really has become a shrill.