Sponsor Message:
Military Aviation & Space Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Question Re Mirv Warheads  
User currently offlineRedFlyer From United States of America, joined Feb 2005, 4364 posts, RR: 28
Posted (7 years 4 months 1 day 23 hours ago) and read 21440 times:

On a MIRV equiped booster, at what point in the trajectory do the independent warheads separate? Is it during the powered boost phase, the non-powered ascent phase, or during the decent phase? Or is it possible to separate and hit diverse targets during any of the three phases of the flight profile?

[Edited 2007-06-26 04:44:02]


My other home is a Piper Cherokee 180C
5 replies: All unread, jump to last
 
User currently offlineRwessel From United States of America, joined Jan 2007, 2368 posts, RR: 2
Reply 1, posted (7 years 4 months 1 day 19 hours ago) and read 21409 times:
Support Airliners.net - become a First Class Member!

The common design is that the bus which holds all the warheads has a small rocket engine, which it uses shortly after the booster separates to maneuver. At appropriate points it pickles off individual reentry vehicles (RVs and various decoys) so that they hit their independent targets.

This happens soon after the booster separates in order to maximize the possible "spread" of targets.

Some RVs also use aerodynamics to further increase cross range capability.

On a few missiles (Trident D5, for example), the individual RVs have some maneuvering capability ("MARV") after they've separated from the bus, to further fine-tune the trajectory.


User currently offlineKC135TopBoom From United States of America, joined Jan 2005, 12158 posts, RR: 51
Reply 2, posted (7 years 4 months 11 hours ago) and read 21290 times:

Quoting RedFlyer (Thread starter):
On a MIRV equiped booster, at what point in the trajectory do the independent warheads separate? Is it during the powered boost phase, the non-powered ascent phase, or during the decent phase? Or is it possible to separate and hit diverse targets during any of the three phases of the flight profile?



Quoting Rwessel (Reply 1):
The common design is that the bus which holds all the warheads has a small rocket engine, which it uses shortly after the booster separates to maneuver. At appropriate points it pickles off individual reentry vehicles (RVs and various decoys) so that they hit their independent targets.

All of the RVs are released before any decent phase, but not during the boost phase. Most are released while the missile reaches orbit.

It is true that some of the warheads are released by a small rocket motor to put them on the correct reentry trajectory towards their targets, others do not need rocket assist.

I think this tread may be getting into areas we shouldn't be talking about. So, this is my last post on this thread.


User currently offlineRedFlyer From United States of America, joined Feb 2005, 4364 posts, RR: 28
Reply 3, posted (7 years 3 months 4 weeks 1 day 20 hours ago) and read 21235 times:

Quoting Rwessel (Reply 1):
The common design is that the bus which holds all the warheads has a small rocket engine, which it uses shortly after the booster separates to maneuver.

If the "Bus" has a small rocket engine, then does its motor burn continuously during its trajectory after booster separation and it releases the RVs at points along that trajectory?

I'm trying to understand how each RV is managed to its independent target. I was under the impression that a ballistic missile is similar to a bullet -- once fired it's pretty much heading in the direction its pointed at (with guidance systems used primarily to keep it on target). So, using the analogy of a bullet, you could have multiple bullets on one cartridge -- such as a shotgun shell with buckshot -- and once fired at a target the individual bullets would spread out (due to aerodynamics) and hit an area around the actual aiming point. I assume that is the process of how MIRV warheads work and that would explain aerodynamics being used to enable cross-range capability. However, is aerodynamics the primary means by which independent targeting is achieved or are their other means, such as the Bus motor? If it's through aerodynamics then does that mean that each MIRV incorporates some form of lifting body?

Quoting KC135TopBoom (Reply 2):
I think this tread may be getting into areas we shouldn't be talking about.

Why?



My other home is a Piper Cherokee 180C
User currently offlineRwessel From United States of America, joined Jan 2007, 2368 posts, RR: 2
Reply 4, posted (7 years 3 months 4 weeks 1 day 20 hours ago) and read 21232 times:
Support Airliners.net - become a First Class Member!

Quoting RedFlyer (Reply 3):
If the "Bus" has a small rocket engine, then does its motor burn continuously during its trajectory after booster separation and it releases the RVs at points along that trajectory?

The burn happens (relatively) briefly near the start of the ballistic flight. The idea is to nudge each RV enough so that the extra velocity accumulated over the entire flight time adjust the impact point as desired. That has to be done at the beginning of the flight. Very roughly, let's say you impart a 300mph nudge to an RV at the beginning of a 20 minute coast. That'll move the impact point roughly* 100mi. The same nudge just before reentry might move the impact point 15-20mi.

While some RV do use aerodynamics to further adjust their impact point, the problem that poses for an ICBM RV is that there is very little time when that's effective (only the last two or three minutes of the flight), which severely limits the amount of "spread" you can get. Some early MIRV'd ICBMs used that technique to scatter several smaller warheads around one large target, the idea being that five 100kt warheads spread a few miles apart will do much more damage to a city than a single MT class warhead right in the center. But that's not quite hitting separate targets.

As a counter example, the Indian Agni III is a bit different in that it uses a rather shallow reentry angle, which gives the RV a lot more aerodynamic flight time.

Remember that in any case, the MIRV'd RVs are going to hit in an ellipse no more than a few (3-4) hundred miles across.



*It's rather more complicated than that - the possible impact points from a given delta-V will form something of an ellipse.


User currently offlineRedFlyer From United States of America, joined Feb 2005, 4364 posts, RR: 28
Reply 5, posted (7 years 3 months 4 weeks 1 day 12 hours ago) and read 21197 times:

Quoting Rwessel (Reply 4):

Great insight. Thanks!  Smile



My other home is a Piper Cherokee 180C
Top Of Page
Forum Index

Reply To This Topic Question Re Mirv Warheads
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Military aviation related posts only!
  • Not military related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Interceptor Velocity Question posted Fri Jun 15 2007 04:58:11 by Blackbird
KC-10/-135 Crew Access Question posted Wed Jun 13 2007 07:21:17 by Cancidas
Spool Up Rate Question posted Wed Jun 13 2007 05:08:18 by Blackbird
Question About Scramjets posted Sun Jun 3 2007 16:56:17 by CJAContinental
Lynx Landing Gear - Question posted Sun May 20 2007 10:39:44 by Loran
Mi-6 Question, Video posted Sun May 13 2007 01:20:20 by OV735
F-16 Question posted Sat May 12 2007 18:22:44 by Tiger119
Behind Enemy Lines Question posted Wed May 9 2007 07:27:49 by Aerlinguscargo
Vulcan XH558 - Any News RE Trials & First Flight? posted Tue Apr 3 2007 21:52:57 by A380Heavy
Il-38 Question. posted Sun Mar 11 2007 18:46:12 by KevinSmith

Sponsor Message:
Printer friendly format