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    Project 955: Borei class SSBN

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    jhelb

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    Re: Project 955: Borei class SSBN

    Post  jhelb on Sat Feb 03, 2018 8:11 pm

    GarryB wrote:Obviously for a falling warhead that is not exactly the same but a few preprogrammed and timed course changes with an ultimate turn to hit the target or get to its most effective detonation point would make it a difficult target for a hit to kill munition.

    Why don't MARVs get some sensors then ? Cruise missile have them.
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    GarryB

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    Re: Project 955: Borei class SSBN

    Post  GarryB on Sun Feb 04, 2018 7:23 am

    Adding radar based sensors would be rather complicated and expensive and to have the range and resolution needed to be effective would take of space and be very expensive... not to mention not really improving accuracy or performance except increasing the chance of dodging a threat that might or might not hit the missile anyway.

    Adding IR sensors has similar problems and having an IR sensor that can look ahead of the warhead looking for climbing interceptors that can detect and track them at a useful range... including during reentry with an enormous IR plume as it enters the atmosphere... and of course the obvious problem... it detects an IR signature... how far away is the intercepting missile? What sort of manouver would the warhead need to perform to evade that interceptor missile and does it have enough fuel to both perform that manouver and still steer back to hit the intended target...

    In comparison a cruise missile can be fitted with simple flare and chaff launchers and a simple IR sensor that can detect an incoming missile from 2-3km... easily enough time to fire off some flares and chaff...


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    jhelb

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    Re: Project 955: Borei class SSBN

    Post  jhelb on Sun Feb 04, 2018 10:49 am

    GarryB wrote:Adding radar based sensors would be rather complicated and expensive and to have the range and resolution needed to be effective would take of space and be very expensive... not to mention not really improving accuracy or performance except increasing the chance of dodging a threat that might or might not hit the missile anyway.

    Adding IR sensors has similar problems and having an IR sensor that can look ahead of the warhead looking for climbing interceptors that can detect and track them at a useful range... including during reentry with an enormous IR plume as it enters the atmosphere... and of course the obvious problem... it detects an IR signature... how far away is the intercepting missile?  What sort of manouver would the warhead need to perform to evade that interceptor missile and does it have enough fuel to both perform that manouver and still steer back to hit the intended target...

    Hmmm..... so a boost phase intercept is not all that difficult. Because the interceptor system generally fires 2-3 exo atmospheric missiles agiant one incoming MARV. Despite pre programmed flight plans the inability to detect in coming interceptor missiles means that MARVs can be effectively targeted. Of course counter measures like baloons etc can help the MARV but even then it's not all that difficult to destroy a MARV in outer space.
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    GarryB

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    Re: Project 955: Borei class SSBN

    Post  GarryB on Wed Feb 14, 2018 6:45 am

    No, pretty much a boost phase is during launch when the booster rockets are operating and you have a nice strong IR signal at the base of each rocket carrying 6 or more warheads.

    Midcourse intercept is when the rockets have all fired to get the warheads moving towards the target and the warheads are coasting towards the target area.

    Boost phase intercept means hitting 100 missiles, mid course intercept means intercepting 600 actual warheads and perhaps 5,000 decoys in space.

    Most MARVs reenter the atmosphere and start manouvering quite early in their flight profile, which is likely to be based on where known fixed ABM sites are... once they start to manouver interception becomes very very problematic because they are no longer flying on a predictable ballistic path but are still travelling at enormous speeds so getting to where they are going before they get there is still tricky.


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    Peŕrier

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    Re: Project 955: Borei class SSBN

    Post  Peŕrier on Wed Feb 14, 2018 5:38 pm

    Against ICBMs, it doesn't work that way.

    An ICBM reach its apogee midcourse, that meaning thousands of kms away from intended targets, and at apogee it is practically in outer space, having reached an altitude ranging between some hundreds kms to several hundreds altitude, depending on how far away the launcher was from the targets and the type of flight path chosen.

    At such altitudes, air attrition is almost not existent, meaning the ICBM can reach, or maintain, any possible speed.

    An old ICBM, in order to maximize practical range, used an almost perfect parabolic course, meaning at its apogee the ICBM had little speed (still several Mach, anyway) and it would regain its energy during descending part of the course, reaching several tens Mach speed.

    Now, that kind of flight path would make, at least theoretically possible to intercept an ICBM at its apogee, provided someone could have a launching platform almost perfectly placed midway from launching spot and targets.

    It is for that reason the US are developing ship based interceptors, because in the end the only practical launching platform for an interceptor would be a prepositioned ship, or better to say a chain of prepositioned ships.

    The russians have developed their last generation of ICBMs, and SLBMs, adopting a shallow orbit right to counter such approach: with a shallow flying path, an ICBM loose some useful range, but even at its apogee maintain a far greater speed, making interception really harder.

    The struggle between an ICBM (or a SLBM) and an interceptor is not on equal terms, and it cannot be: launching spots are either deep in others' own territory or unknown (if the missiles are SLBMs), so interception could start only when the ICBM is already flying outside the Atmosphere.

    It could travel almost as fast as its designers chose to make it, while the interceptor will struggle against aerodynamic attrition trying to reach an estimated interception point ahead of present ICBM's position, and ahead means really far ahead.

    So the interceptor, if trying to perform an apogee's interception, will have to travel hundreds of kms upwards, having only a very little opportunity's window to actually intercept the ICBM: any little error in speed estimation, better to say on speed's change along the trajectory estimation, would guide the interceptor either too ahead or too past the ICBM.

    In the final course, interception would be even harder: reentry vehicles, once released, will reach in few seconds speeds beyond any conceivable feasibility for an interceptor. In the last part, the will fly at speeds several tens Mach, and even the slightest change in course will make impossible for an interceptor to successfully compute the new target's speed and course, an interception trajectory, and then actually implement it.

    Decoys, then, are not balloons: they are inert devices acting just like reentry vehicles: their goal is to aim at plausible targets, forcing the opponent to intercept all of the existing tracks.

    They exists because present treaties put a cap on the available number of actual warheads deployable in an ICBM.

    The ICBM being able to carry far more payload, decoys are the obvious solution to reduce dramatically chances of terminal path's interception.

    If no cap would exist, any ICBM would likely bring far more reentry vehicles and no, or only a few decoys.
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    GarryB

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    Re: Project 955: Borei class SSBN

    Post  GarryB on Thu Feb 15, 2018 6:33 am

    At such altitudes, air attrition is almost not existent, meaning the ICBM can reach, or maintain, any possible speed.

    No they can't.

    Once the final third stage has burned out that is their top speed. They might gain a little speed as they fall through the latter phase of flight but they don't gain more than they lost on the climb up to their highest point unpowered.

    An old ICBM, in order to maximize practical range, used an almost perfect parabolic course, meaning at its apogee the ICBM had little speed (still several Mach, anyway) and it would regain its energy during descending part of the course, reaching several tens Mach speed.

    You are clearly confused between a vertical zoom climb and a ballistic projectile... even through the drag of the atmosphere a projectile starts to lose speed once it has left the muzzle of the artillery piece that fired it, and it loses velocity all the way to the target while it is unpowered.

    For an ICBM however it is generally powered all the time it is in the atmosphere so once the last stage fires it wont accelerate very much at all for the rest of the flight and when it enters the atmosphere it will slow down... but in any event it will never exceed escape velocity... otherwise it wont be coming back.

    Mid course interceptors like the ones the US is building in eastern europe can intercept targets thousands of kms up moving at very high speeds... that is why they had to withdraw from the ABM treaty to build and test them.

    It is harder to intercept them there because there is no bright rocket plume showing you where the missile is and you can destroy lots of warheads and decoys together inside one rocket with one shot like you could with a boost phase interceptor.

    Of course the new Russian rockets have high energy short burn rockets that get their warheads up into space rapidly so the warheads and decoys can be deployed rapidly too so it is harder to intercept them.

    Now, that kind of flight path would make, at least theoretically possible to intercept an ICBM at its apogee, provided someone could have a launching platform almost perfectly placed midway from launching spot and targets.

    By the apogee the warheads and decoys are already deployed, meaning hundreds or thousands of targets instead of one.


    It is for that reason the US are developing ship based interceptors, because in the end the only practical launching platform for an interceptor would be a prepositioned ship, or better to say a chain of prepositioned ships.

    Sounds like an excellent target for a 100 megaton armed torpedo that is fired to a particular location and detonated... or for that matter a depressed trajectory missile that air bursts in the upper atmosphere above these ships and ionises the airspace above them for the next hour or two making radar tracking impossible.


    The russians have developed their last generation of ICBMs, and SLBMs, adopting a shallow orbit right to counter such approach: with a shallow flying path, an ICBM loose some useful range, but even at its apogee maintain a far greater speed, making interception really harder.

    What are you talking about?

    You need the latest generation of ICBM or SLBM to fly a depressed trajectory?

    Really?

    Then how do 12,000km range TOPOLs get aimed at targets in Europe?

    The INF treaty bans intermediate range missiles so they could not use them...

    The interception missiles the US is basing in eastern europe have been tested on satellites which move fast enough to remain in orbit and are therefore rather faster than any ICBM or SLBM warhead... otherwise those satellites would fall back to earth like anything else that fails to reach orbital speed.

    It could travel almost as fast as its designers chose to make it, while the interceptor will struggle against aerodynamic attrition trying to reach an estimated interception point ahead of present ICBM's position, and ahead means really far ahead.

    Actually they can travel as fast as the designers choose to make them but making them fast enough to stay in orbit means you need an extra rocket motor to deorbit them. Fractional orbit bombardment system, or FOBS... look it up.

    The speed is not important as I mentioned as long as the targets are detected early enough and their flight path calculated...

    So the interceptor, if trying to perform an apogee's interception, will have to travel hundreds of kms upwards, having only a very little opportunity's window to actually intercept the ICBM: any little error in speed estimation, better to say on speed's change along the trajectory estimation, would guide the interceptor either too ahead or too past the ICBM.

    The flight path of the interceptor could be engineered to be a head on interception so that the interceptor flys along the flight path of the target, and then it is just a case of releasing small fragments in the path of the target... impact with which would destroy any object at such closing speeds.

    In the final course, interception would be even harder: reentry vehicles, once released, will reach in few seconds speeds beyond any conceivable feasibility for an interceptor. In the last part, the will fly at speeds several tens Mach, and even the slightest change in course will make impossible for an interceptor to successfully compute the new target's speed and course, an interception trajectory, and then actually implement it.

    Actually the last phase interception is much easier... reentry vehicles accelerate due to gravity and accelerate at 9.8m/s/s, which is not inconceivable and when they start to hit the atmosphere they will actually start to slow down.

    Decoys, then, are not balloons: they are inert devices acting just like reentry vehicles: their goal is to aim at plausible targets, forcing the opponent to intercept all of the existing tracks.

    Decoys that act like warheads would need to have the same size and shape and weight as a warhead... so basically they would weigh as much as a warhead and take up the same space as a warhead.... you might as well just carry an extra warhead.

    metalised balloons on the other had can be carried in enormous numbers and when released in space will be hard to differentiate from real warheads...

    In fact you can put metalised balloon material around your real warheads so the difference is even less obvious...

    They exists because present treaties put a cap on the available number of actual warheads deployable in an ICBM.

    No they don't. there is no limit on the number of warheads an ICBM or SLBM can carry. One of the later START agreements banned heavy ICBMs with multiple MIRVs but that was not ratified by the US so it never went into effect.

    That is why the first TOPOLs had one warhead each but now they put three warheads in them.

    If no cap would exist, any ICBM would likely bring far more reentry vehicles and no, or only a few decoys.

    The cap on the total number of warheads allowed means the total number of warheads they can threaten the US with is limited, but the ability to carry an unlimited number of decoys means determining which is a warhead and which is a decoy much much harder.



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    Arrow

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    Re: Project 955: Borei class SSBN

    Post  Arrow on Thu Feb 15, 2018 5:28 pm

    Of course the new Russian rockets have high energy short burn rockets that get their warheads up into space rapidly so the warheads and decoys can be deployed rapidly too so it is harder to intercept them. wrote:

    No boost phase of TopolM-M/Yars is about 3 min. Older MM III and Trident have a similar boost time.

    Peŕrier

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    Re: Project 955: Borei class SSBN

    Post  Peŕrier on Thu Feb 15, 2018 7:13 pm

    ICBM are not pure ballistic weapons.

    They steer during boost phase, steer on the exo-atmospheric path, and still maintain a steering capability during MIRVs release.

    Soviet/Russian ICBM, at least those employing some liquid fuel stage, add the ability to actually change and regulate their acceleration and exo-atmospheric speed.

    So it's nearly impossible to predict in advance a possible point of interception, limiting greatly useful range of interception from ground based interceptors.

    The Topol-M, and Bulava as well, have exploited the liquid fueled third stage to push things further: they could be launched along a shallow trajectory, can perform not only the usual minor course adjustments, but actual course changes, and can at least theoretically even change speed, making any intercept a gamble.

    By the way, most interceptor rely on hit-to-kill warhead, because it seems to be deemed too likely that any proximity fused warhead won't succeed in destroying the ICBM during mid-course trajectory.

    Only terminal phase interceptors, as the old soviet Gazelle and the US Sprint, relied on proximity fuzing, but that using nuclear warheads.

    The problem stays always the same: an interceptor could start engaging an ICBM only when the ICBM is already in the exo-atmospheric part of its trajectory. So there is a little window of opportunity left, and even minor course adjustments by the ICBM would be hard to counter on the interceptor side, real course change would easily bring the interceptor out of chances.

    So, it's not true that ICBM are easily targeted as satellites: satellites as well are not that easy to target, old school ICBMs were/are way harder, new evasively maneuvering ones could turn out to be a real challenge.

    And by the point of view of the interceptor, the real problem is given by the translational speed of the ICBM, not its absolute speed. A shallower trajectory means a greater part of the absolute speed is made of translational speed, and proportionally less of vertical speed.

    About the MIRVs, they are not released mid-course, or better to say there is no proof they are actually, or have to be released mid course. The final stage could actually bring them for most of the path before releasing them, and again Topol-M and Bulava, with their liquid fueled third stages allegedly able to even shut-off and restart, will restrain from releasing the payload until reached a point were evasive maneuver is no longer feasible or less effective than releasing multiple potential targets (either MIRVs or single warhead plus decoys).

    By the way, MIRVs accelerate typically during their first trajectory correction phase and in the initial dive, start to decelerate as soon as they re-enter atmosphere.

    But starting their dive at speed typically in excess of 20000 km/s, they are almost impossible to intercept at least with hit-to-kill warheads. Nuclear tipped one should of course still be effective, even if they could turn out to be politically unpalatable.

    Just a last note: Arrow 3, promising a engagement range in excess of 1500 kms, is actually a rocket putting more or less in orbit a smaller rocket able to independently recognize, aim and engage the target, the warhead being actually propelled by a real and independent rocket engine.

    I believe (just my own two cents, of course) that this shows what even for the ICBM the future would be: a comparatively highly maneuvering rocket carrying maneuvering payloads.

    Topol-M and Bulava have already started the path, and future versions or new missiles will try to extend further those evading capabilities.

    And the decoys should actually emulate real RVs: Arrow-3 warhead is allegedly already able to discriminate real payload from decoys, any radar reflective decoy will have to emulate actual behavior of an RV, not just to fall from the sky giving a large enough radar echo.
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    GarryB

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    Re: Project 955: Borei class SSBN

    Post  GarryB on Fri Feb 16, 2018 3:47 am

    ICBM are not pure ballistic weapons.

    They don't have wings like a cruise missile... the B in ICBMs says that they are ballistic weapons.

    The fact that they can use thrusters to correct their flight path does not mean they are not ballistic weapons.

    They steer during boost phase, steer on the exo-atmospheric path, and still maintain a steering capability during MIRVs release.

    They can steer during those phases... they don't continuously steer during those phases...

    They can adjust their course but they don't continuously steer because steering costs fuel and they have only a limited amount of onboard fuel available.

    Soviet/Russian ICBM, at least those employing some liquid fuel stage, add the ability to actually change and regulate their acceleration and exo-atmospheric speed.

    The pre MARV warheads make occasional corrections in trajectory... they simply don't have enough fuel to do more.

    MIRV buses carry all their warheads together and the whole bus manouvers to release warheads at targets on the way... but even they will fly a fairly simple path to a release point and then burn fuel to change trajectory to the next release point.

    So it's nearly impossible to predict in advance a possible point of interception, limiting greatly useful range of interception from ground based interceptors.

    Oh, please... If you take a globe and draw a line from the known launch pads in Iran and North Korea to the top of the USA and to the bottom of the USA and then add a twist to counter for the earths rotation during their flight and you get an area through which all ICBMs fired at the US from either of those two countries must pass... anywhere along that triangle you can put ground based interceptors... the further away from the launch position it is the more time it will have for the interception because those launch pads are watched 24/7.

    Satellites have fuel to maintain altitude for long period operational times and can be moved to avoid impacts with debris in orbit, yet there are missiles that have been tested that can shoot down those satellites... and to remain in orbit those satellites must move faster than any object launched from earth that lands back down on earth.

    The Topol-M, and Bulava as well, have exploited the liquid fueled third stage to push things further: they could be launched along a shallow trajectory, can perform not only the usual minor course adjustments, but actual course changes, and can at least theoretically even change speed, making any intercept a gamble.

    All MIRVed missiles have a liquid bus stage that releases each warhead to a different target... they don't waste fuel speeding up or slowing down it is just side to side for the trajectory needed for each MIRV to hit its target.

    By the way, most interceptor rely on hit-to-kill warhead, because it seems to be deemed too likely that any proximity fused warhead won't succeed in destroying the ICBM during mid-course trajectory.

    Proximity fused warheads would be interesting... with the target moving at about 7km/s and the interceptor moving at almost any possible angle depending on the interception parameters, being half a second early means missing by 3.5km and no conventional warhead would help there...

    Only terminal phase interceptors, as the old soviet Gazelle and the US Sprint, relied on proximity fuzing, but that using nuclear warheads.

    Technology has move on from then.

    I have seen folding mesh warheads that simply expand and increase the chance of contact... I suspect the directed fragment warhead of the S-300 did not come from nowhere either...

    Arthur C Clarke said the easiest way to destroy a satellite is to put a bucket of nails on an opposing orbit... even if you miss, then 45 minutes later you get another chance with the expanding cloud of nails... a better chance... and even a nail with a closing speed of 14km/s would be devastating.

    The problem stays always the same: an interceptor could start engaging an ICBM only when the ICBM is already in the exo-atmospheric part of its trajectory. So there is a little window of opportunity left, and even minor course adjustments by the ICBM would be hard to counter on the interceptor side, real course change would easily bring the interceptor out of chances.

    Quite true, but how would the ICBM know when to change course at exactly the right time... and the best time to move would be 2-3 seconds before impact because starting to move wont be detected by ground control and the degree of the movement would be able to be calculated for a few seconds, so the command to compensate would not be possible either...

    The point is that for Iranian or North Korean missiles they will just be dumb MRVs or at best MIRVs and not MARVs like the Russians have.

    So, it's not true that ICBM are easily targeted as satellites: satellites as well are not that easy to target, old school ICBMs were/are way harder, new evasively maneuvering ones could turn out to be a real challenge.

    Only new MARVs are hard... older model ICBMs and SLBMs are quite straight forward... though of course hardly easy.

    About the MIRVs, they are not released mid-course, or better to say there is no proof they are actually, or have to be released mid course. The final stage could actually bring them for most of the path before releasing them, and again Topol-M and Bulava, with their liquid fueled third stages allegedly able to even shut-off and restart, will restrain from releasing the payload until reached a point were evasive maneuver is no longer feasible or less effective than releasing multiple potential targets (either MIRVs or single warhead plus decoys).

    MIRVs are not used against one target... the I means independently targeted... In other words on the flight path towards the most distant target warheads are released from the warhead bus to hit targets on the way... a missile launched from Russia might pass right through the middle of europe releasing warheads for London and Paris and brussels and Poland and germany and belgium... the warhead bus in this case wont contain all the warheads when it gets to London... it will have released them on the way, with however many left when it gets to london... london is a big place but each ICBM or SLBM will likely only have one warhead allocated to the target london. Their might be 5 or 6 different missiles with one warhead aimed at london, so london will get hit with 5 or 6 warheads from 5 or 6 different missiles because london is a big target.

    The US is a much further away target so to hit from one side to the other the warheads will have to be released much earlier so the range of targets can be hit.

    Of course they might split the country and have missiles hitting targets on one coast or the other and other missiles going right down the middle...

    By the way, MIRVs accelerate typically during their first trajectory correction phase and in the initial dive, start to decelerate as soon as they re-enter atmosphere.

    By gravity, not by rocket booster.

    But starting their dive at speed typically in excess of 20000 km/s, they are almost impossible to intercept at least with hit-to-kill warheads. Nuclear tipped one should of course still be effective, even if they could turn out to be politically unpalatable.

    Check your numbers my friend... twenty thousand kilometres per second is faster than anything man has ever achieved by an enormous margin... eleven kilometres a second will escape earth orbit and take you out into deep space..., so even if you just meant 20,000 m/s you are still way off because that is still almost double escape velocity...

    I'll give you a hint... the S-500 is designed for shooting down ICBMs and it is optimised for target speeds of 7km/s, though it can hit faster targets in some circumstances...

    The international space station is moving at 7.67 km/s which is about 27,600 km/h or 17,200 mph, so objects moving at that speed at 400km altitude above the earth don't fall down... they stay in orbit...

    And the decoys should actually emulate real RVs: Arrow-3 warhead is allegedly already able to discriminate real payload from decoys, any radar reflective decoy will have to emulate actual behavior of an RV, not just to fall from the sky giving a large enough radar echo.

    They don't have to make decoys look like warheads... it is much easier to make warheads look like decoys...



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    jhelb

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    Re: Project 955: Borei class SSBN

    Post  jhelb on Fri Feb 16, 2018 7:28 am

    GarryB wrote:Most MARVs reenter the atmosphere and start manouvering quite early in their flight profile, which is likely to be based on where known fixed ABM sites are... once they start to manouver interception becomes very very problematic because they are no longer flying on a predictable ballistic path but are still travelling at enormous speeds so getting to where they are going before they get there is still tricky.


    Why do they start maneuvering so early in the flight profile ? They are loosing a lot of energy in the process.


    GarryB wrote:once they start to manouver interception becomes very very problematic because they are no longer flying on a predictable ballistic path

    Interception won't be a problem. At least 2 - 3 interceptor missiles will be fired. MARVs can manoeuvre slightly (unlike fighter jets) because MARVs don't have sensors. So if one missile misses the other 2 will surely strike the MARV.
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    Singular_Transform

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    Re: Project 955: Borei class SSBN

    Post  Singular_Transform on Fri Feb 16, 2018 8:05 pm

    jhelb wrote:
    GarryB wrote:Most MARVs reenter the atmosphere and start manouvering quite early in their flight profile, which is likely to be based on where known fixed ABM sites are... once they start to manouver interception becomes very very problematic because they are no longer flying on a predictable ballistic path but are still travelling at enormous speeds so getting to where they are going before they get there is still tricky.


    Why do they start maneuvering so early in the flight profile ? They are loosing a lot of energy in the process.


    GarryB wrote:once they start to manouver interception becomes very very problematic because they are no longer flying on a predictable ballistic path

    Interception won't be a problem. At least 2 - 3 interceptor missiles will be fired. MARVs can manoeuvre slightly (unlike fighter jets) because MARVs don't have sensors. So if one missile misses the other 2 will surely strike the MARV.

    Means that they need 2-3 interceptor for each warhead : )

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    miketheterrible

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    Re: Project 955: Borei class SSBN

    Post  miketheterrible on Fri Feb 16, 2018 8:08 pm

    interceptor missiles don't operate just on their own. They need continuous guidance from ground radar and even if fired in seconds apart, it makes no difference. They rely on basic trajectory, and when the trajectory changes for the missile, it becomes a problem for the missile interceptors. I have no idea what jhelb is even commenting about 3 interceptor missiles because adding 3 interceptor missiles will not make interception more likely. Just means you wasted 3 interceptor missiles because the ballistic missile is still changing trajectory.
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    PapaDragon

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    Re: Project 955: Borei class SSBN

    Post  PapaDragon on Fri Feb 16, 2018 8:41 pm

    Singular_Transform wrote:...............
    Means that they need 2-3 interceptor for each warhead : )

    And if you miss just one that's half a million people dead now plus that many more until weekend

    Any you will definitely miss way more than one
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    miketheterrible

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    Re: Project 955: Borei class SSBN

    Post  miketheterrible on Fri Feb 16, 2018 8:56 pm

    PapaDragon wrote:
    Singular_Transform wrote:...............
    Means that they need 2-3 interceptor for each warhead : )

    And if you miss just one that's half a million people dead now plus that many more until weekend

    Any you will definitely miss way more than one

    Judging by lack of capabilities of THAAD and SM3 in intercepting old SCUD missiles, I have significant less faith in it being able to take out a Topol Warhead. Topol-M, Yars, Rubezh. Sineva, etc is completely out of the question.
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    PapaDragon

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    Re: Project 955: Borei class SSBN

    Post  PapaDragon on Fri Feb 16, 2018 9:25 pm

    miketheterrible wrote:................
    Judging by lack of capabilities of THAAD and SM3 in intercepting old SCUD missiles, I have significant less faith in it being able to take out a Topol Warhead. Topol-M, Yars, Rubezh. Sineva, etc is completely out of the question.

    And with that we are back to ye' good old Mutually Assured Destruction

    Thank you for dedication to sports but better not to play the match....

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    Re: Project 955: Borei class SSBN

    Post  Peŕrier on Fri Feb 16, 2018 9:39 pm

    It was a typo, I meant 20000 m/s, my fault.

    And yes, RVs loose speed because air attrition, but the point is it is an exponential deceleration, growing with loss of altitude and the Atmosphere getting denser.

    When RVs start their dives, they have so much speed it is actually hard to intercept them.

    It is of course possible, at least in theory, but the chances are really low.

    Again, Arrow-3 approach to the problem is quite interesting.

    Its extremely long range is likely meant to engage an incoming or traversing ICBM well outside the Atmosphere, and rely in final stage that's fully powered.

    It could be, my opinion, that the missile actually reach a trajectory intersecting the estimated ICBM's one, release its final stage that scan toward the last estimated ICBM's course, as it lock it start modifying its trajectory to actually make it colliding  against the ICBM.

    The real selling point should be obviously the final stage, that together with its onboard sensors act as the warhead as well.

    Having the ability to get and move along the trajectory followed by the ICBM should already be quite a feat, but being able to effectively change course fully autonomously up to impact with enough kinetic energy to destroy the ICBM is the real stunt.

    So again, evasive changes of course on the ICBM are the only effective countermeasure.

    Obviously, they are not performed every two or three seconds, it is enough to make some pseudo-random change along the whole of the path, in function of   the likely time of flight needed by an interceptor. if an interceptor need one minute from the start to reach the ICBM, already a single course change performed around a little less than that time would make the interceptor's life really hard.

    A a last note, I do not think is possible to make a RV in any way similar to a decoy. A RV has strict requirements coming from its payload, its reentry characteristics and so on.

    But future decoys would have to be real multi-spectrum decoys. even if being by physical size's point of view smaller, they will have to have the same radar echo against several different wavelengths, the same thermal spectrum, the same light brighteness, and they will have to dive the same exact way a real RV does.

    Even against UV sensors, or whatever other EM wavelength could be exploited to realize a sensor either active or passive, they should have the same footprint as a real RV.

    Sensors, electronics and algorithms will develop always way faster than rockets and the likes: a decoy to field tomorrow should be designed today to fully and totally fool whatever could be fielded to counter it ten or more years from now.
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    Re: Project 955: Borei class SSBN

    Post  Singular_Transform on Fri Feb 16, 2018 9:42 pm

    miketheterrible wrote:interceptor missiles don't operate just on their own. They need continuous guidance from ground radar and even if fired in seconds apart, it makes no difference. They rely on basic trajectory, and when the trajectory changes for the missile, it becomes a problem for the missile interceptors. I have no idea what jhelb is even commenting about 3 interceptor missiles because adding 3 interceptor missiles will not make interception more likely. Just means you wasted 3 interceptor missiles because the ballistic missile is still changing trajectory.

    That is the point, they try to cover all possible trajectory with the missiles.

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    Re: Project 955: Borei class SSBN

    Post  miketheterrible on Fri Feb 16, 2018 9:45 pm

    Singular_Transform wrote:
    miketheterrible wrote:interceptor missiles don't operate just on their own.  They need continuous guidance from ground radar and even if fired in seconds apart, it makes no difference.  They rely on basic trajectory, and when the trajectory changes for the missile, it becomes a problem for the missile interceptors.  I have no idea what jhelb is even commenting about 3 interceptor missiles because adding 3 interceptor missiles will not make interception more likely.  Just means you wasted 3 interceptor missiles because the ballistic missile is still changing trajectory.

    That is the point, they try to cover all possible trajectory with the missiles.


    But when launched, at the process of when it was launched vs the time it is going to reach the target, all 3 of the missiles will be basing it off of an older trajectory. They will not have a different span of the trajectory any different from the previous missiles fired at it, at the given time the warheads trajectory has changed.
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    Re: Project 955: Borei class SSBN

    Post  kvs on Fri Feb 16, 2018 10:34 pm

    The new generation of glider warheads is basically the final nail in the ABM coffin. No interceptor can afford to chase gliders in
    vast horizontal pathway excursions at high altitude. The premise of an ABM warhead is rapid interception and not target chasing.
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    Re: Project 955: Borei class SSBN

    Post  GunshipDemocracy on Sat Feb 17, 2018 3:48 am

    kvs wrote:The new generation of glider warheads is basically the final nail in the ABM coffin.   No interceptor can afford to chase gliders in
    vast horizontal pathway excursions at high altitude.   The premise of an ABM warhead is rapid interception and not target chasing.

    Not entirely true. You talk about 1 interceptor vs one warhead if i am correct. then what if you got 10or 20 interceptors? trajectory? you can actually calculate all possibl evariants og trajectories in advance and just adopt situational awareness parameters accordingly in calculations (Boyd's loop).

    ABM also will evolve develop for example: into either small autonomous rockets/drones carried into orbit to intercept warheads or will be also completed with weapons "based on new principles" .

    Eventually one ASAT carrier will have many sub-munitions to cover all possibe variations of glider in close range?
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    Re: Project 955: Borei class SSBN

    Post  GunshipDemocracy on Sat Feb 17, 2018 4:06 am

    Peŕrier wrote:It was a typo, I meant 20000 m/s, my fault.

    And yes, RVs loose speed because air attrition, but the point is it is an exponential deceleration, growing with loss of altitude and the Atmosphere getting denser.


    and how you suppose to have "exponential acceleration" without engine running? or conversion of potential vs kinetic energy doesn't apply anymore? Yeah there is one acceleration called standard acceleration of free fall (g)




    When RVs start their dives, they have so much speed it is actually hard to intercept them.
    It is of course possible, at least in theory, but the chances are really low.

    The question is the price of so many interceptors vs 1 warhead.



    Again, Arrow-3 approach to the problem is quite interesting.
    Its extremely long range is likely meant to engage an incoming or traversing ICBM well outside the Atmosphere, and rely in final stage that's fully powered.

    It could be, my opinion, that the missile actually reach a trajectory intersecting the estimated ICBM's one, release its final stage that scan toward the last estimated ICBM's course, as it lock it start modifying its trajectory to actually make it colliding  against the ICBM.

    The real selling point should be obviously the final stage, that together with its onboard sensors act as the warhead as well.


    As long as ICBM didn't release warheads it is required t send less. This is IMHO the reason to build long range interceptors.






    So again, evasive changes of course on the ICBM are the only effective countermeasure.

    Obviously, they are not performed every two or three seconds, it is enough to make some pseudo-random change along the whole of the path, in function of   the likely time of flight needed by an interceptor. if an interceptor need one minute from the start to reach the ICBM, already a single course change performed around a little less than that time would make the interceptor's life really hard.


    knowing about mass and energy of warhead you can calculate all possible trajectories it can fly. Depending on which moment you want to hit the ICBM (ideally when it is in active phase
    - all warheads in one place) you know where it potentially can send you warheads. The business is how to optimize number of ABM interceptors not having to build 50 for every warhead.


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    Re: Project 955: Borei class SSBN

    Post  GarryB on Sat Feb 17, 2018 10:45 am

    Why do they start maneuvering so early in the flight profile ? They are loosing a lot of energy in the process.

    The target location is pretty fixed, as is the areas where ABMs can be located, so you get the MARV to start manuovering at the point where is could start to be intercepted with manouverings calculated to allow the target to still be hit, but to maximise the chances of the warhead surviving to target.

    Interception won't be a problem. At least 2 - 3 interceptor missiles will be fired. MARVs can manoeuvre slightly (unlike fighter jets) because MARVs don't have sensors. So if one missile misses the other 2 will surely strike the MARV.

    Really... it is that easy is it? So if it starts to climb and turn will all three adapt to that manouver or just one? If it changes direction 3 times then all three will miss... once they have perfected scramjet engines they could fit one to each warhead so they could accelerate inside the atmosphere and manouver freely... a 5 degree turn will take a while for the tracking system to detect and recalculate an intercept point for... the interception point could have shifted hundreds of kms... it would only take a few seconds for the interceptor to change course but if it then turns back 10 degrees then the interceptor might have to turn and move 500km the other way... is there time for that? Does the inteceptor have that much fuel?

    Remember a mid course interceptor in Alaska might not be within 1,000km of the flight path of the target going over the north pole on its way to New York, so you might have to launch as soon as the target is detected coming over the pole... it might be heading for middle America and then over Canada turn to target new york... will your interceptor be able to move that far that fast after already travelled 2,000km from where it was launched from?

    And what about the fact that there are 20,000 targets of which perhaps 600 are actually warheads and the rest are decoys... by the time they re enter the atmosphere it is too late because it will be only seconds to detonation...

    How about making things fun by launching a satellite before the full scale attack... it fails and is dead in orbit... but as it passes over the US it detonates... a 100MT nuclear bomb blocks out all radar and radio waves for hours and the EMP pulse damages electronics over the whole US of A... and then Russia launches its missiles to attack...

    It was a typo, I meant 20000 m/s, my fault.

    I thought as much but it is still wrong... 11000m/s is escape velocity...

    When RVs start their dives, they have so much speed it is actually hard to intercept them.

    No it isn't... satellites in orbit move faster... that space craft that landed on that comet was moving faster than anything that is man made and falls back from space.

    A a last note, I do not think is possible to make a RV in any way similar to a decoy. A RV has strict requirements coming from its payload, its reentry characteristics and so on.

    By the time they are reentering the atmosphere it is too late to intercept them... perhaps 60-70kms max of real atmosphere... well who am I kidding... there is fuck all above about 30km... so moving at about 6 or 7km/s they have about 5 or 6 seconds to impact with the ground... so 3-4 seconds to detonation for an air burst...

    The new generation of glider warheads is basically the final nail in the ABM coffin. No interceptor can afford to chase gliders in
    vast horizontal pathway excursions at high altitude. The premise of an ABM warhead is rapid interception and not target chasing.

    Gliders that skip across the atmosphere will be tricky, but if they add scramjet engines to allow them to actually fly and accelerate inside the atmosphere then the defenders are in trouble... really only lasers and beam weapons are an option...

    The question is the price of so many interceptors vs 1 warhead.

    And the amusing problem... the large missile they were going to deploy in eastern europe had a range of 2,500km which means it would violate the INF treaty... the size of the weapon would mean its cost was likely a very large fraction of that of an ICBM if not more...

    Eventually one ASAT carrier will have many sub-munitions to cover all possibe variations of glider in close range?

    With a scramjet engine the warhead could dip into the atmosphere and accelerate to a high enough speed to climb back out of the atmosphere and into partial orbit... there is no upper flight speed for a scramjet engine...

    knowing about mass and energy of warhead you can calculate all possible trajectories it can fly. Depending on which moment you want to hit the ICBM (ideally when it is in active phase
    - all warheads in one place) you know where it potentially can send you warheads. The business is how to optimize number of ABM interceptors not having to build 50 for every warhead.

    That is like trying to calculate all the possible flight paths of a helicopter from a helo pad to its destination... it is not infinite, but it is variable enough to result in too many alternatives to conceivably cover.

    It is like the Serbian shoot down of the F-117 some claim it was never tracked or detected and the only reason they shot it down was because it repeated its flight path over and over... well even if you got a precise bus time table and took a rifle and fired 10 shots where you expected it to be the chances of actually hitting the bus would be zero... even if you launched 122mm grad rockets by the thousands you still would not hit it.

    Obviously they detected it and got enough of a lock to shoot it down.

    the real problem in this case is that the warhead has tons of energy... it is after all falling... and also moving very very fast.

    Even a small angular change in trajectory in three dimensions means an intercept point can change by hundreds of kms in seconds... but more importantly change back or even further the other way seconds later... even with multiple interceptors such changes would be hard to manage and counter... and is it a warhead or a decoy?

    How about this... decoys are very light so only make the decoys manouver in the mid course phase... being very light it would not take very much fuel at all... and only move some of them... MARVs separate from the warhead bus after final stage burn out, so warheads and decoys deploy very very early...


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    Re: Project 955: Borei class SSBN

    Post  GunshipDemocracy on Sat Feb 17, 2018 12:29 pm

    GarryB wrote: ed to allow the target to still be hit, but to maximise the chances of the warhead surviving to target.

    Interception won't be a problem. At least 2 - 3 interceptor missiles will be fired. MARVs can manoeuvre slightly (unlike fighter jets) because MARVs don't have sensors. So if one missile misses the other 2 will surely strike the MARV.


    Last time  I have listened to a Russian military he mentioned something like 50 interceptors per warhead.




    GarryB wrote:
    It was a typo, I meant 20000 m/s, my fault.

    I thought as much but it is still wrong... 11000m/s is escape velocity...


    .

    11,2 actually if you dont take into consideration latitude  or not and rotating body effect Twisted Evil Twisted Evil Twisted Evil






    GarryB wrote:
    The question is the price of so many interceptors vs 1 warhead.

    And the amusing problem... the large missile they were going to deploy in eastern europe had a range of 2,500km which means it would violate the INF treaty... the size of the weapon would mean its cost was likely a very large fraction of that of an ICBM if not more...


    That's exactly why IMHO they say Russian warheads can overcome ABM. Too costly build enough interceptors to cover all possible paths.







    GarryB wrote:
    Eventually one ASAT carrier will have many sub-munitions to cover all possibe variations of glider in close range?

    With a scramjet engine the warhead could dip into the atmosphere and accelerate to a high enough speed to climb back out of the atmosphere and into partial orbit... there is no upper flight speed for a scramjet engine...


    it would be  definitely complicate interception process but so far it is not yet technically solved problem its it?


    GarryB wrote:
    knowing about mass and energy of warhead you can calculate all possible trajectories it can fly. Depending on which moment you want to hit the ICBM (ideally when it is in active phase
    - all warheads in one place) you know where it potentially can send you warheads. The business is how to optimize number of ABM interceptors not having to build 50 for every warhead.

    That is like trying to calculate all the possible flight paths of a helicopter from a helo pad to its destination... it is not infinite, but it is variable enough to result in too  many alternatives to conceivably cover.



    The next step would be to move "mother" interceptors as close as possible before releasing its (interceptors' ) multiple targetable warheads  And of course nobody says it's "piss of kaka"   but this is exactly where supercomputer simulations and AI algorithms enter the game.
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    Re: Project 955: Borei class SSBN

    Post  jhelb on Sat Feb 17, 2018 12:45 pm

    GarryB wrote:Really... it is that easy is it? So if it starts to climb and turn will all three adapt to that manouver or just one?

    Garry, how will a falling object like a [MARV] warhead start to climb ?


    GunshipDemocracy wrote:Last time  I have listened to a Russian military he mentioned something like 50 interceptors per warhead.

    This is interesting because I've checked every single Russian source that I could find but never found anything close to 50 interceptors per warhead.

    Never mind. Did he provide any explanation as to why 50 interceptors need to be fired per warhead. For instance if a Minuteman III is heading towards Moscow will the S-500, S-400 systems fire 50 interceptors towards the Minuteman's MARVs ?




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    Re: Project 955: Borei class SSBN

    Post  Singular_Transform on Sat Feb 17, 2018 1:46 pm

    jhelb wrote:
    GarryB wrote:Really... it is that easy is it? So if it starts to climb and turn will all three adapt to that manouver or just one?

    Garry, how will a falling object like a [MARV] warhead start to climb ?


    GunshipDemocracy wrote:Last time  I have listened to a Russian military he mentioned something like 50 interceptors per warhead.

    This is interesting because I've checked every single Russian source that I could find but never found anything close to 50 interceptors per warhead.

    Never mind. Did he provide any explanation as to why 50 interceptors need to be fired per warhead. For instance if a Minuteman III is heading towards Moscow will the S-500, S-400 systems fire 50 interceptors towards the Minuteman's MARVs ?





    It can be assessment of the minimum required interceptors from a certain kind against a certain warhead.


    There can be case when you need 50 interceptors to have chance to kill one warhead.

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