SwingKid, THis might be of interest to you.

[GGTharos]

http://ed-thelen.org/

 

http://ed-thelen.org/simulation.html

 

In particular notice how the missile is brought up to full speed. Perhaps this could be of use for minizap? Maybe some sort of setup like this is what gets the 54C up to its vaunted mach 5 or 6 top speed?

[SwingKid]

Re: SwingKid, THis might be of interest to you.

 

In particular notice how the missile is brought up to full speed.

 

My friend, thanks for the interesting link, but you really need to narrow down your references by quoting some of the exact text from the documents you're linking to. That sub-link code is 150 pages! How do I find how the missile is brought to full speed?

 

Perhaps this could be of use for minizap? Maybe some sort of setup like this is what gets the 54C up to its vaunted mach 5 or 6 top speed?

 

Insofar as the Nike Hercules is launched vertically, from a non-moving, ground-level platform, uses a first-stage booster that falls away after launch, and the simulation code appears to not have any drag modelled at all, but rather uses numerous "cheats..." maybe... :)

 

On the other hand I thought the part about "initial boost and then dive until horizontal," followed by a horizontal (?) "cruise to kill" was very interesting, and justifies miniZAP's "loft glide logic" model... Without any references, I had found this experimentally, that the range of the missile is maximized not on a pure parabolic trajectory dropping down on the target from above as I always assumed the Phoenix to work, but rather levelling out into a horizontal cruise after an initial dive.

 

The debunking continues... 8)

 

Do you have a believeable reference for the "Mach 5 or 6" of the Phoenix?

 

-SK

[GGTharos]

Urg ... sorry about that.

 

There's also some text that relates to missile speed ... though I'm not entirely certain as to wether it is correct or not.

 

Here it is:

 

27) 30 seconds

- - - the missile is flying at Mach 3.75 (2,815 miles per hour), toward Predicted Point of Intercept

- - - about 8.5 miles high and 12 miles down range from the launcher

- - - missile sustainer rocket motor has run out of fuel, missile coasting

 

28) 40 seconds

- - - the missile is flying at Mach 3.5 (2,625 miles per hour), toward Predicted Point of Intercept

- - - about 8.5 miles high and 20.2 miles down range from the launcher, missile coasting

- - - "Track #5" (without IFF)) appears on the radar, and is assigned to this battery as next target

 

29) 50 seconds

- - - the missile is flying at Mach 3.25 (2,435 miles per hour), toward Predicted Point of Intercept

- - - about 7.75 miles high and 28.5 miles from the launcher, about 16 miles from "Track #2"

- - - the target and missile are approaching head on, missile coasting

 

30) 60 seconds

- - - the missile is flying at Mach 3.25 (2,435 miles per hour), toward Predicted Point of Intercept

- - - about 6.7 miles high and 36.6 miles from the launcher, about 4.9 miles from "Track #2"

- - - the target and missile are approaching head on, missile coasting

 

31) 64.6 seconds

- - - the missile and target are both 40.15 miles from the launcher, 6.2 miles high

- - - the missile explodes slightly above and 30 feet in front of target

- - - explosion and metal fragments turn "Track #2" into unflyable wreck, a wing comes off.

 

 

From here: http://ed-thelen.org/alert.html

 

The missile doesn't seem to slow down very much.

 

As for the Phoenix, that is the usual speed that's quoted, other than that, no ... then again if you consider how fast SAMs can allegedly travel despite short burns in some cases, I think it's not -too- far fetched, though I have been indeed unable to get it up there with minizap. Mach 4.something was the best I could do, and I don't even recall what my parameters were (I probably modified the specific impulse something fierce)

 

I don't know if you have looked such things up but, would it help if I tried to search for some NASA data on high altitude rocket-flight as it relates to drag etc?

 

Also, are you going to update minizap for a leveling out cruise? :D

[SwingKid]

From here: http://ed-thelen.org/alert.html

 

Hmm... This is interesting... I could add the Nike Hercules to miniZAP... :)

 

The missile doesn't seem to slow down very much.

 

Interesting dilemma... My critic with the "real data" suggested miniZAP missiles weren't decelerating enough, wheres this would indicate they're decelerating too much? :?

 

I don't know if you have looked such things up but, would it help if I tried to search for some NASA data on high altitude rocket-flight as it relates to drag etc?

 

Hard to judge if it will be helpful until I see it... I think I already scoured the web for whatever was there but you never know what I missed (e.g. this nice site about Nike Hercules).

 

Also, are you going to update minizap for a leveling out cruise? :D

 

That's what the first click of "Loft Glide Logic" currently does.

 

-SK

[GGTharos]

Hmm, it looks liek the Herc boosts while diving ... if I recall the timeline correctly, it accelerates in the climb (which is actually a dive. ie it's going up but already turning towards the target) and continues accelerating or boosting through some (probably small) part of its level cruise - this is why I ask. your loft-glide logic still has the missile jumping up as high as it can.

 

even in teh SLAMRAAM videos the AMRAAM levels out partially or completely before the rocket motor burns out, but obviously that may be highly dependant on target altitude.

 

I'll see what I can find ... keep in mind that your expert did tell you that your missiles behave correctly, IF you had the correct parameters, as I recall ... could this be part of the problme also?

 

Naturally, this timeline may also be faulty in some manner as well, however it seems that the herc only drop about what ... .5 mach in 20sec?

[GGTharos]

Have yous een this, by any chance?

 

http://www.aerorocket.com/aerodrag.html

[SwingKid]

even in teh SLAMRAAM videos

 

Link?

 

Have yous een this, by any chance?

 

http://www.aerorocket.com/aerodrag.html

 

No... Also interesting, thanks!

 

-SK

[GGTharos]

PM'd the link.

[zzzspace]

Re: SwingKid, THis might be of interest to you.

 

On the other hand I thought the part about "initial boost and then dive until horizontal," followed by a horizontal (?) "cruise to kill" was very interesting, and justifies miniZAP's "loft glide logic" model... Without any references, I had found this experimentally, that the range of the missile is maximized not on a pure parabolic trajectory dropping down on the target from above as I always assumed the Phoenix to work, but rather levelling out into a horizontal cruise after an initial dive.

 

The debunking continues... 8)

-SK

 

 

I’m not sure this horizontal profile has anything to do with range optimisation SK.

 

If you watch a Patriot PAC3 test, the hit to kill vehicle does not fly a PN lead intercept, what the system does is;

 

1. it projects the 3-D trajectory and flight track of the target

 

2. then it launches and attempts to race the interceptor to a location well ahead of the targets projected flight path

 

3. then the kill vehicle is oriented head-to-head with the target

 

4. Then it kills the target via head-on collision (no warhead required).

 

This aligning in front of the target manoeuvre is performed in order to minimise the lateral movement of the target vector with respect to the kill vehicle's path, and thus allows simplified terminal manoeuvring to a direct head-on contact energy kill which no warhead or aircraft can survive.

 

This same head-to-head logic, allowing simplified terminal intercept, will likewise apply to an older long-range and comparatively low terminal manoeuvrability heavy air defence missile, such as Nike.

 

In other words, a vertical launch with high arcing trajectory, but the dive and horizontal flight phase is not a cruise flight phase, instead, it's associated with the initiation of a terminal manoeuvre, which against a bomber will indeed be a horizontal head to head terminus for Nike Hercules.

 

(an aircraft or missile designer wishing to defeat a hit to kill SAM like PAC3 had better ensure frontal IR and RCS signature are minimal and the ability for instantaneous high-G side-stepping manoeuvres is very high, plus decoy spoofs are effective)

[SwingKid]

Re: SwingKid, THis might be of interest to you.

 

2. then it launches and attempts to race the interceptor to a location well ahead of the targets projected flight path

 

3. then the kill vehicle is oriented head-to-head with the target

 

4. Then it kills the target via head-on collision (no warhead required).

 

This aligning in front of the target manoeuvre is performed in order to minimise the lateral movement of the target vector with respect to the kill vehicle's path, and thus allows simplified terminal manoeuvring to a direct head-on contact energy kill which no warhead or aircraft can survive.

 

Never heard of anything like this before... It would seem to be pretty inefficient against anything but a non-maneuvering target, making the PAC-3 susceptible to Wild Weasel tactics designed to deplete the magazine. Where did you first learn about it? Maybe GGTharos came across this in the guidance PDFs?

 

-SK

 

 

This same head-to-head logic, allowing simplified terminal intercept, will likewise apply to an older long-range and comparatively low terminal manoeuvrability heavy air defence missile, such as Nike.

 

In other words, a vertical launch with high arcing trajectory, but the dive and horizontal flight phase is not a cruise flight phase, instead, it's associated with the initiation of a terminal manoeuvre, which against a bomber will indeed be a horizontal head to head terminus for Nike Hercules.

 

(an aircraft or missile designer wishing to defeat a hit to kill SAM like PAC3 had better ensure frontal IR and RCS signature are minimal and the ability for instantaneous high-G side-stepping manoeuvres is very high, plus decoy spoofs are effective)

[zzzspace]

Its called a dog-leg manoeuvre SK.

 

It may be range inefficient, perhaps, but the aim is maximising POK for the BM RV’s warhead, and that takes priority over secondary range-efficiency considerations.

 

As far as I know, this dog-leg is used on in-coming RVs. It is unclear if it’s also used against aircraft, but of the manned aircraft which have been hit (IFF error) by PAC3, all crew were killed, possibly suggesting a head-to-head kinetic energy impact.

 

I have a video of a PAC3 dog-leg intercept, but I’m still looking to see if there is one online.

 

“ …The PAC-3 interceptor itself, 17.1 feet long and 10 inches in diameter, is an upgraded version of the PAC-2. The main difference lies in the kill mechanism: while the PAC-2 uses an exploding warhead to eliminate its targets, the PAC-3 is a hit-to-kill system and destroys its targets by the kinetic energy released in a head-on collision. Another difference is that the PAC-3 interceptors, enhanced by the advanced radar and command center, are capable of protecting an area approximately seven times greater than the original Patriot system …”

 

http://www.missilethreat.com/systems/pac3.html?PAGE_PRINT=yes

[zzzspace]

It's not the video I'm after but this RealPlayer video shows a pronounced dog-leg maneuver - shows a PAC-3 kill vehicle intercepting a patriot 2 missile which is acting as a the PAC-3's target:

http://www.redstone.army.mil/pub_affairs/PAC-3DT-8video.ram

 

Here's an LM promo video of it, but the terminal dog-leg maneuver and interception is less clearly displayed as other videos I've seen:

http://www.lockheedmartin.com/data/assets/2187.mpeg

 

Note the forward thruster for rapidly re-orienting the missile's main engine thrust and vector. It seems this is how the dog-leg is accomplished for PAC-3.

 

PAC-3 Head to head contact KE kill: