ICBM/RV Questions Thread

TheArmenian wrote:How many km per second does a typical ICBM travel at?

Some time ago, someone posted a good post on the speeds of ICBMs and IRBMs. Can't find it now.

Topol M in terminal phase is moving at about 7km per second.

TheArmenian wrote:How many km per second does a typical ICBM travel at?

Some time ago, someone posted a good post on the speeds of ICBMs and IRBMs. Can't find it now.

ICBMs and SLBMs travel at 7km/s . No one has built any nuclear weapon faster than that. IRBMs travel at lesser speed.

max steel wrote:

TheArmenian wrote:How many km per second does a typical ICBM travel at?

Some time ago, someone posted a good post on the speeds of ICBMs and IRBMs. Can't find it now.

ICBMs and SLBMs travel at 7km/s . No one has built any nuclear weapon faster than that. IRBMs travel at lesser speed.

well..

A-135 kinetic anti ballistic near space defense ,armed with a nuclear warhead
travels at 8.5km/s  that is mach 25.0 .never say is impossible.  

https://en.wikipedia.org/wiki/A-135_anti-ballistic_missile_system



the newer version A-235.. should be a bit faster or about same speed.



http://missilethreat.com/defense-systems/a-235-samolet-m/


But make no mistake.. you don't need fast speed to intercept an ICBM ,look at
american SM-3 space mines that are launched in space by a rocket. deployed in front of the predicted trajectory of any ICBM. As long it is deployed in the right path from where the missile will pass it can intercept it even if very slow the mine repositioning.

The advantage of a fast missile is however is that it can chase an ICBM and intercept it from behind.. American SM-3 Aegist can't do that. IT can only intercept by collision if deployed earlier on the right flight path of any missile.. If any missile do maneuvers early it will be hard for SM-3 to intercept it..since is not a missile interceptor but more like a mine that is deployed in space by a cheap rocket booster.

S-500 will be a real beast if work as good as S-400 with with high altitude space range.
Will be awesome if Russian latest destroyers or Kirov class came with a dozen of S-500s.

I remember reading that ballistic missile subs can launch their missiles from home base(without being on patrol). Delta III and IV subs can launch their missiles from the pier. But can subs with solid-propellant Bulavas do the same ?

They had a few Bulava test launches from surfaced subs, but when they talk about SSBNs launching from the pier they are basically talking about the flight range of their missiles allowing them to hit their targets without having to sail any closer than their piers.

I found this part related to MIRVs in Wikipedia :

In a MIRV,the main rocket motor (or booster) pushes a "bus" (see illustration) into a free-flight suborbital ballistic flight path. After the boost phase the bus maneuvers using small on-board rocket motors and a computerised inertial guidance system. It takes up a ballistic trajectory that will deliver a reentry vehicle containing a warhead to a target, and then releases a warhead on that trajectory. It then maneuvers to a different trajectory, releasing another warhead, and repeats the process for all warheads.


Minuteman III MIRV launch sequence: 1. The missile launches out of its silo by firing its first-stage boost motor (A). 2. About 60 seconds after launch, the 1st stage drops off and the second-stage motor (B) ignites. The missile shroud (E) is ejected. 3. About 120 seconds after launch, the third-stage motor (C) ignites and separates from the 2nd stage. 4. About 180 seconds after launch, third-stage thrust terminates and the post-boost vehicle (D) separates from the rocket. 5. The post-boost vehicle maneuvers itself and prepares for reentry vehicle (RV) deployment. 6. While the post-boost vehicle backs away, the RVs, decoys, and chaff are deployed (this may occur during ascent). 7. The RVs and chaff reenter the atmosphere at high speeds and are armed in flight. 8. The nuclear warheads detonate, either as air bursts or ground bursts.

The precise technical details are closely guarded military secrets, to hinder any development of enemy counter-measures.

I need some explanation about the last sentence. Which details are closely guarded military secrets?

Tolstoy wrote:

I need some explanation about the last sentence. Which details are closely guarded military secrets?

Everything beyond a general description is top secret.

Basically the bus is like an aircraft and the MIRV warheads are dumb bombs... the aircraft manouvers to a flightpath that puts any released bombs on a ballistic path to the target and releases them one at a time with manouvers before release to ensure they get close to the target.

The fine details are secret to prevent anyone else doing the same who does not already have that capability.

Most previous nuclear systems either only have one warhead or several that fall together to kill a large area target like a city.

with the old MRVs three to four warheads would be delivered per city target in a spread to ensure good destruction.

with MIRVs you still hit a city with three to four warheads but they will be from different missiles so that if one missile is shot down with all its warheads... or more likely one missile fails then each targets will still get two to three hits from the other missiles.

Obviously only missiles whose flight path takes it near the target can be used to hit those targets... you can't aim a MIRV and targets in completely different directions from the launch position.

GarryB wrote:The fine details are secret to prevent anyone else doing the same who does not already have that capability.

Ok. So I was wondering how can Russia develop countermeasures to US MIRVs if it doesn't have detailed knowledge about the way MIRVs manoeuvre. As a Russian this is of concern to me.

Tolstoy wrote:

GarryB wrote:The fine details are secret to prevent anyone else doing the same who does not already have that capability.

Ok. So I was wondering how can Russia develop countermeasures to US MIRVs if it doesn't have detailed knowledge about the way MIRVs manoeuvre. As a Russian this is of concern to me.

Its vice-versa, "We both got long sticks".

Tolstoy wrote:Ok. So I was wondering how can Russia develop countermeasures to US MIRVs if it doesn't have detailed knowledge about the way MIRVs manoeuvre. As a Russian this is of concern to me.

For the record Russia Defense systems ( A-135(Gazelle)) can intercept Minuteman III and Trident (containing MIRVs) in terminal range. The incoming S-500( mobile ) and A-235 (immobile) will do it in higher range.Meanwhile US Ground based Interceptors can't even intercept China's ICBM reliably let alone Russia's.





This forum has lost many dedicated contributors over the years.

Ok. So I was wondering how can Russia develop countermeasures to US MIRVs if it doesn't have detailed knowledge about the way MIRVs manoeuvre. As a Russian this is of concern to me.

First of all if anyone tells you about you being safe under an ABM umbrella then they are lying to you.

The game of measure and counter measure is continuous and ongoing.

Think of a MIRV as a glide bomb rather than a manouvering cruise missile.

When released from the bus they are basically released heading directly at their target with some manouvering capability to fine tune that accuracy and hit the target more precisely.

A MaRV is an actively manouvering reentry vehicle that can perform active manouvers to evade ground and air based threats and head specifically to a point target.

Because it has its own propulsion and guidance it can hit targets much further from the flight path of the carrier rocket and can change its flight path significantly more than a simple MIRV can.

Much more difficult to hit.

Hitting a MIRV is like a TOR hitting a laser guided bomb... a laser guided bomb will perform small flight corrections to ensure a precise hit on a point target but will not manouver all that much.

In comparison a MaRV is actively trying to evade the defences around the target...

GarryB wrote:
Think of a MIRV as a glide bomb rather than a manouvering cruise missile.

What are the requirements that an ICBM/SLBM need to fulfil before it can carry MIRVs? I understand not all ICBMs/SLBMs can carry MIRVs.

I didn't think even China has that capability but last month RT reported that even Pakistan has developed long range ballistic missile that can carry MIRVs.

Basically a MIRV is a bus mounted in the nose of the missile that carries the warheads.

The bus can manouver by itself... so the missile is launched and the first stage falls away after getting the whole missile airborne and up to speed... the second stage then carries itself and the third stage towards the target area... when it burns out the final stage is in space so no drag and the bus has a limited capability to manouver... it does not have the fuel or the energy to do 90 degree turns or deviate enormous distance from its normal ballistic flight path but it can turn to release a warhead in the direction of a target on its flight path... when it does so the re entry vehicles or warheads just fall on the target... like a dumb bomb.

This design means if your sub is in the north sea and you launch a missile towards the UK, you could also send warheads to targets in western europe... but not in the opposite direction to Japan for instance.

An ICBM missile from Iran travelling over europe to the US could drop warheads on various european targets on the way past for instance.

Previous missiles were not really accurate enough to hit point targets and with an accuracy of a kilometre or so you just used them against a city.

With a target like London it is such a wide area to get a decent level of damage hitting it with 4-6 warheads is much more effective than even hitting it with a really big warhead. each warhead does not need to be precision placed... just an even spread is good enough so a MIRV is a waste of time... a scatter of 4-6 MRVs is plenty.

Of course sometimes missiles fail so having MIRVed warheads from say 6 different SLBMs means one on each missile could be aimed at a different place in London... so a Missile launched from the North Sea might hit 10 targets in the UK... one target being London. Another missile from a different sub near Murmansk might have one warhead headed for London and one for Paris and Brussels.... so one warhead from 6 different missiles from 6 different subs from 6 different directions might be programmed to hit London... if one missile fails the other 5 hits will ensure Londons destruction... of those six missiles a second warhead on each might be going for Brussels and one for Paris.

All targets needing to be hit will be covered with warheads from other missiles so if one missile fails or is shot down then there will be enough other warheads to ensure the job gets done anyway.

Concerning SLBM's technology, I used to believe the US were far more advanced than USSR regarding this technology. Because the first good soviet SLBM was SS-N-6 Serb deployed by the soviet navy around the end of the 60s. Meanwhile, the US were on the verge to deploy the SLBM Poseidon at the same time.
It clearly shows that USSR bet on ICBM instead of SLBM. Because it was logical, USSR was a huge area, there were enough areas secret areas to hide ICBM, in fact, USSR was a huge ocean of ground. However, at that time most of the soviet ICBM -SS-17, SS-18, SS-19 - were liquid propellants, meanwhile US's ones that were solid propellant. The MX, Minuteman all were solid propellant as the SLBM Poseidon, and Trident I.
To prepare a Missile it takes far more time for liquid propellant than solid propellant. Thus I thought USSR lagged behind the US regarding SLBM. But I was suspicious about Soviet ICBM. We had to wait until SS-24 to see a good ICBM with solid propellant. Why? The question seems to be more complex than I thought. Here is a possible explanation.

The USSR solid rocket fuel tech was in the 1970s inferior to that of the USA. But after the 1990s there has been at least a factor
of two doubling of energy density of Russian solid rocket fuel compared to the Soviet variants. This is a very big deal since the size
of Russian SLBMs and rail launched ICBMs can be a factor of two smaller in weight and relative volume compared to what the USSR
could deploy.

In terms of guidance and other aspects of missile tech, there was no real gap with the US. The numbers about Soviet CEP being
a factor of 10 worse than that of the US ICBMs is pap for the ignorant.

Liquid fuelled rockets started out being rather volatile and were only fuelled just before launch because their propellents were dangerous and volatile and could not be stored for long terms in the missile for fear of a problem occurring.

Even the Kh-22 and Kh-22M need to be fuelled up before use.

The thing is that they solved those problems with newer ballistic missiles so their ICBMs and SLBMs are fuelled when they are made, so for the life of the missile it is fuelled and ready for launch.

For space launch rockets the fuels are normally cryogenic so the rockets are still not fuelled till the last minute for safety reasons.

limb wrote:Why can't the Topol-M, Yars and Bulava carry manevering reentry vehicles in general and the avangard specifically?

Not enough throw weight. Plus they are pre-built with anti-ABM countermeasures, so its kind of a waste.

Topol m and yars warhead can change trajectory.

https://m.washingtontimes.com/news/2005/nov/20/20051120-115514-2217r/

limb wrote:
The DF-21 has a maneuvering RV tho, and its an IRBM.

what's the IC in ICBM?