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Long Range Precision Fires

sferrin

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What is the exact speed of an atacms missile? Will the PRSM fly above the mach 5?
If it reaches out to 800km it'll likely be well over that. The Iskander-M is Mach 5.9 at 500km range, the first DF-15 was Mach 6 at 600km range and Pershing I was Mach 8 at 740km range. But then PRISM isn't purely ballistic. But it's still likely to be more like Mach 6-7.
And Atacms speed? How fast is it?
It's not published. And it's not a ballistic weapon. (In other words it's a guess at best.)
 

Lc89

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And Atacms speed? How fast is it?
Mach 3+ but that's carrying a 500lb warhead and only has a 300km range.
I remember that to test X51 Waverider they used an Atacms booster that pushed the aircraft up to mach 4.5 before the booster activated the scramjet and detached itself from it. So I expect the PRSM to go faster than mach 4.5.
 

sferrin

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Only Wired and National Interest


Mach 4.5 when launched from a B-52 with an X-51 Waverider (4,000lb).

It wouldn't surprise me if the speed was nearer Mach 4-4.5 from the ground with a 500lb warhead.
The National Interest quote (Mach 3) is after burnout, on it's way down. (Assuming they have accurate sources.) With the X-51 burnout was closer to Mach 4.8 IIRC.

"The Atacms ignited and propelled the entire 25-ft.-long stack—including the booster, inter-stage and X-51A cruiser—for 29 sec. until it reached 63,000 ft. and Mach 4.9. The cruiser separated and coasted to Mach 4.8 before the scramjet was started using ethylene. "


And that's with the X-51 upfront, which by itself weighed just over 1400lbs.

Capturex51.PNG

Also the missile isn't strictly speaking, a ballistic missile:

 

Forest Green

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That is from an air-launch at circa 550mph though, however from the ground with only 500lb up front, a similar speed would probably be reached. PRISM should be way beyond that speed.
 

sferrin

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That is from an air-launch at circa 550mph though, however from the ground with only 500lb up front, a similar speed would probably be reached. PRISM should be way beyond that speed.
I would think the ground launch would reach a higher speed. Warhead is only a 3rd of the weight of the X-51 (and it's adapter and associated hardware) and drag will be significantly less.
 

Forest Green

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I would think the ground launch would reach a higher speed. Warhead is only a 3rd of the weight of the X-51 (and it's adapter and associated hardware) and drag will be significantly less.
The warhead is 1/3rd of the weight but the missile as a whole is about 3/4 of the weight and it is starting from rest and travelling through 4x denser air against gravity at launch. So whilst Cd will probably be lower, drag likely won't. So Mach 4-4.5 is a sensible estimate.
 

sferrin

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"What we learned over the year from the initial investments is that what we thought could be 600-650 [km] really could get out to 750, maybe even 800,” Rafferty says. The additional range totals remain only an analytical conclusion. The Army continues to review a potential requirement change for the maximum range of the PRSM, he adds.

That theoretical limit applies to both competitors in the PRSM program—Lockheed Martin and Raytheon. "


 

bobbymike

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Army preparing to award contracts for Strategic Long Range Cannon
The Army is forging gun tubes and readying initial contracts for a new system intended to operate with the Long Range Hypersonic Weapon in the opening salvos of a major fight against a near-peer military force. The Strategic Long Range Cannon is a prototype mega-cannon envisioned to fire rounds hundreds of miles at high-priority enemy radar and air-defense sites, namely those of Russia and China
 

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jsport

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Where is the Airborne SLRC for Boost Phase Ballistic Missile Defense (Mike Griffin stated goal) and SEAD so Hypersonic missile is not intercepted. ;)
 

Lc89

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Will the strategic gun be built in a single copy? I believe so, because it will be expensive. Being an artillery system there will be no problem with missile range.
 

TomS

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Will the strategic gun be built in a single copy? I believe so, because it will be expensive. Being an artillery system there will be no problem with missile range.
Really, it's going to be a rocket/missile launcher using a cannon barrel for the first stage. Same basic naming principle as the Navy's Advanced Gun System, which was sometimes described as a trainable rocket launcher.
 

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Really, it's going to be a rocket/missile launcher using a cannon barrel for the first stage. Same basic naming principle as the Navy's Advanced Gun System, which was sometimes described as a trainable rocket launcher.
I suspected this. Launching a shell 1,000nm with no rocket motor would require unbelievable amounts of power. It might be more like this.

 

sferrin

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I thought there was a graph that showed 1,400nm for the SFM and 1,000nm for the SLRC?

View attachment 621261
That list appears to be incomplete.
 

sferrin

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Will the strategic gun be built in a single copy? I believe so, because it will be expensive. Being an artillery system there will be no problem with missile range.
Really, it's going to be a rocket/missile launcher using a cannon barrel for the first stage. Same basic naming principle as the Navy's Advanced Gun System, which was sometimes described as a trainable rocket launcher.

(Scramfire below)
p2000a549g113001.jpg
 
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