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Subject: Command guided shells getting smaller
doggtag    3/15/2007 2:02:10 PM
From DefenseUpdate.Com: US Army to Evaluate C-RAM Gun System The US Army is seeking countermeasures to defeat incoming enemy rocket, artillery and mortar (RAM) attacks. As part of the Extended Area Protection & Survivability (EAPS) program the Army plans to evaluate gun-based countermeasures currently under development at Alliant Techsystems (NYSE:ATK). The company received a $4.6 million contract from the U.S. Army Armament Research, Development and Engineering Center (ARDEC), to develop and demonstrate a 50mm gun and ammunition system that will be fired from a derivative of the ATK's Bushmaster cannon. The projectile will employ course-correction techniques based on commands received via data-link. ---- 50mm guided shells. SWEET. (links to follow)
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doggtag       3/15/2007 2:05:34 PM
the actual DefenseUpdate link:
(it's about 3/4 down the page)
And from ATK's own press releases:
And the 50mm Bushmaster III that will fire it:
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reefdiver       3/15/2007 2:41:16 PM
so if it can course correct, for ground fire perhaps you could have it "curve" into trenches and foxholes and around corners...of course some of the new smart fuzed airburst rounds might work better for that purpose... but it sounds fun
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doggtag    Yes it sounds "fun"   3/15/2007 3:21:23 PM
I've brought up this subject before in some form or another, wondering where gun-launched PGM (Precision Guided Munition) tech was going to take us.
I've mentioned the 40mm command-guided shells the US tested back in the 1980s (yes, done with 1980s tech), possibly as a munition for the now-long-defunct Sgt York DIVADS twin-40mm-guns-on-an-M48-hull air defense tank.
I've mentioned the formerly-FMC-then-became-United-Defense-and-now-is-part-of-BAe expiremental ElectroThermal Chemical gun, firing 60mm command-guided shells at around 1300m/sec, mounted on a modified Phalanx CIWS trunnion system/turret base, tested back in the early 1990s (and I wonder if it may have influenced the decision on using the 57mm naval gun in the LCS and DDX/DDG1000).
I've mentioned the triple cluster of 35mm diameter guided darts that the Starstreak missile fires (hypervelocity MANPADS used by the UK and others). Look around on the web, there was at least a couple videos showing its flight, and the darts maneuvering around a bit to strike a ground target. Starstreak also began development in the late 1980s-early 1990s.
And I've mentioned the DARPA & BAe joint attempt on the ODAM optically guided (laser seeking?) 60mm mortar round program (there are even radio-frequency 81mm concepts that survived beyond the expensive Merlin mm-wave round, but they're still developmental also).
Now, I can understand the issues they're having with GPS-guided artillery shells (127mm for naval & 155mm for land artillery, and from what I understand the issues seem to be more around the rocket motor propulsion more than the actual GPS guidance).
But I still see it as, if Ford Aerospace and Vought could design (competitive designs?) 40mm guided shells with 1980s-era technology, I don't quite understand why it hasn't been pursued more intently until now (post-2000).
Back in1984, there was a Tom Selleck movie called Runaway, in which he played a cop going up against a bad guy (Gene Simmons) with a hand cannon (literally) that fired miniature homing rounds with microshell explosive warheads that tracked a transmitter "bug" planted on his targets.
Seems we're getting there eventually (sometimes Hollywood actually gets the future right!).
 It's obviously achievable now to use a 35mm guided round (Starstreak uses a cluster of 3, each about a half meter long).
So I'm curious just what levels of precision in what size munitions we'll actually be able to achieve.
The long range sniping weapon of the future may fire a steerable 20-25mm round to 2 miles or so with precision measured in inches/centimeters.
But for the role the US is testing it for, a land-based CIWS in effect, others have suggested its rounds & fragments may leave an unfavorable downrange danger area. Some have suggested DEWs like THEL lasers would be more favorable, with the only hazardous debris being the destroyed inbound munition.
But using programmable airburst rounds, we are closer to using land-based CIWS built around shell-firing guns than we are to usings lasers, or even railguns.
Judging by the blast radius of the pre-fragmented 40mm Bofors rounds coupled to the 3P fuze, an airburst in 50mm should be quite impressive (search "40mm programmable tank" for videos online about the CV9040).
...And if such a caliber perks enough customer interest, will AFVs be in line to receive this gun caliber next, for ammo commonality issues as well as downrange performance?
I'm curious if ATK will increase the Bushmaster's rate of fire (curretly 200 shots per minute in the Mk III, which is still higher than a WW2 40mm Bofors gun), or if fire control algorythms will be more than adequate enough in programming the shells to detonate at the most ideal time (only a few rounds needed vs a dozen or more).
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Jeff_F_F       3/15/2007 5:50:29 PM
Sounds like a nice system. 50mm would do nice things to armor too. I wonder at what point you get a single gun that can just kill anything on the battlefield--aircraft, infantry, tanks.
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HIPAR       3/15/2007 9:03:25 PM
I worked on a 120 mm command guided projectile project that was conceived to allow a tank protect itself from attacks by helicopters.  It was steered by a ring of explosive impulse thrusters.  We actually verified the thrusters provided adequate command authority with a wind tunnel test.

The command link is a very difficult problem.  Everyone wants to use a laser and we did indeed try to make several laser schemes work during live fire testing.  No laser command link ever worked consistently. A millimeter wave data link was being tested when the project was canceled.

A command guided projectile is one of those ideas that will forever recur.  Someday, the technology might actually mature.

---  CHAS

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Yimmy       3/15/2007 9:21:08 PM
HVM uses laser just fine.

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reefdiver       3/16/2007 12:07:54 AM
I see the 120mm M1 tank fired Mid-Range (Laser Guided) Munition is progressing. Would it be possible to use that against moving targets - like vehicles or even helicopters? 
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doggtag       3/16/2007 10:52:46 AM
Was the "anti-helo" 120mm round the STAFF round by chance, HIPAR? 
Or is/was that a different egg altogether?
On another note: the Italians (OTO Melara) has been developing the Davide DART (Driven Ammunition Reduced Time of flight) subcaliber guided round for the 76mm/62 naval gun family.
That TV show Future Weapons showed a Starstreak System mounted on a truck and some video of the darts maneuvering (seen thru the thermal viewer).
Seems it's reasonably accurate enough and fires at a fairly high velocity (>Mach 3), although it's quite short-ranged compared to artillery/gun-fired PGMs (the longer the range, the more fire-and-forget you need the munition to be, unless you have spotter/designators downrange).
As for the MRM (ATK's also) round, the article over at DefenseUpdate.Com suggests in trials it has proven capable of hitting moving targets (no mention of the target's speed):
 But again, being a beyond-line-of-sight weapon, it's seekerhead needs downrange illumination (which shouldn't be difficult for the planned mini/micro UAVs the US Army has planned).
What will get interesting is,
will a move to 50mm AFV guns (dual mode, anti-surface/anti-air) generate renewed interest in IMI's (or OTO Melara's) 60mm hypervelocity gun?
Seems Rafael developed that little Firefly "reconn grenade"
(and a small pdf is available over at Rafael's website, but you have to type "Firefly" in their search engine to find it),
which does nothing more than transmit back imaging data. But it still proves one of the initial steps- implementing seeker/scanner technologies and datalinks (even if only one-way in the Firefly)- into such a small round.
...So does anyone think Rafael may eventually demonstrate a guided round for the IMI 60mm, in attempts to get a share of the market also (if C-RAM shows its merit)?
And might Bofors/BAe offer up some new land system with the heavier-hitting 57mm naval gun equipped with an improved 3P fuze (shades of the CV9040 anti-air model with its UTAAS sight) to perform the same role as we may see in a production 50mm (Bushie III or Rheinmetall Rh503)?
 Or, like ODAM, could the 50mm be little more than proof-of-concept demonstrator, with final suggestions being that technical hurdles prevent an actual fieldable system in said caliber?
(Guess I'll have to wait for NDIA's next few defense conferences and armaments exhibitions).
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HIPAR       3/16/2007 6:43:14 PM
Was the "anti-helo" 120mm round the STAFF round by chance, HIPAR?

If I remember correctly, STAFF was administered by the Precision Munitions Division at ARDEC.  I worked in the Fire Control Division.

Our project (ca 1987) was funded by DARPA as a technology demonstration.  The projectile was a fin stabilized 120 mm full bore projectile that was optimized for steerability.  The fins were canted slightly causing the round to slowly roll.  A ring of pyrotechnic impulse thrusters provided for course diversion.  There was a millimeter wave tracking beacon in the boat-tail. 
The MMW tracker also to measured the projectile roll position to determine when to fire a thruster. The kill  mechanism was not important to the demonstration so we never went into its design but a HEAT or standoff fragmentation concept would have been reasonable.

We had evaluated several FLIR based autotracking devices to track the helo.  The M1 Tank night sight was proposed for a possible operational system. 

With today's technology, this projectile could probably steer itself using an on-board seeker.

The guided projectile project that was 'IN' during that time frame was called X-Rod.  It was a rocket assisted sabot type of thing.  I believe it was not successful because the guided dart would go unstable when it was commanded to change course.

When X-Rod secured all of the DARPA funds, we closed down the project before we could integrate and flight test the system.

I'm also aware of several command guided kinetic kill projects that were initiated for the Anti Ballistic Missile defense.

---  CHAS

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Jeff_F_F       3/16/2007 6:59:41 PM
My first thought when I read this was 60mm or even 75mm Hypervelocity guns. New composite barrel technologies with a ceramic liner and composite overwrap should overcome the barrel wear problems that have limited the adoption of these weapons in the past.
On the other hand, as much as I like the idea of a kill anything tank, I suspect it isn't the plan. The main reason for this feeling is that while developing a conventional round at a prototype caliber smaller than the planned full scale weapon makes sense, developing a guided round that is smaller than the planned caliber is a lot harder so why bother with the effort. Also historically, combined arms between specialist vehicles usually works better than generalist vehicles. I also doubt that we'll create tanks mounting both conventional heavy guns and medium close defense/air defense guns. What we'll probably see is a mix of vehicles armed with each type. Assuming these weapons are being integrated with the FCS concept either we'd see a new vehicle that hasn't been planned yet, or we'll see one of the current vehicles armed with these weapons. My gut says that this will be the ICV. It seems like I've seen it planned to use a 40mm gun for this vehicle, but upping it to 50mm autocannon should be doable.
The option of making a separate vehicle is intriguing, however. The vehicle's capabilities seem like they'd be very much like what I was talking about in my post to the "What's next for western MBTs thread" about what it would take to effectively counter the FCS system. Only I didn't consider the possibilty that the heavy automatic cannon and the close defense system could be one and the same. This could be a hedge against other nations developing an FCS type system and using it against us. :

 What capabilities would an asymetric threat tank need to beat FCS. Not Asymetric as in terrorist but rather asymetric as in not trying to beat the FCS by being more FCS than the FCS.

 It seems these would fall into the categories of weapons, defenses, signature reduction, and detection avoidance. I look at signature reduction as making it harder to detect the tank with a given sensor, while detection avoidance would be things like ESM.
Primary weapon might be a heavy automatic cannon, since FCS tanks are planned to be much lighter than conventional tanks.

Armor might be similarly light due to the power of the antitank weapons being arrayed against it.

A good directed energy weapon could be key: either a laser or powerful AESA radar with DEW capabilites to take out stand off weapons at range. This would also be useful in combination with ESM to counter enemy drones and sensors such as airborne radars. This could cross over between several areas: weapons, defenses, and detection avoidance.

It should be shaped to either reduce its radar cross section or to avoid giving a radar cross section that is easily detectable. Perhaps radar "camoflage" that breaks up its shape on radar so it is hard for radar sensors to recognize it as a tank. In the air anything that reflects radar is a target. On the ground everything reflects radar, so only things that move and--if the radar has imaging capabilities--looks like a target is interesting.

It could either have heavy antitank weapons to defeat heavy tanks like M1s, or it could act as a screening force for the enemy's heavy tanks (presumably also networked) working to take out the FCS UAVs and blind as many sensor systems as possible, destroying light FCS vehicles and scouting for heavy M1s and other heavy armor while using a combination of mobility, low observables, and sensor supression to avoid anything it can't beat. The networked heavy armor would then engage any opposing heavy armor encountered with the advantage of superior situational awareness on their side.
Of course the IFV could have these capabilities, but the mission is a bit different. This seems more like a screening recon/cavalry vehicle in a 3D battlefield, rather than a IFV which should be supporting infantry. On the other hand, we use the Bradley in both roles, why not the FCS IFV? For the IFV, the mission would be supporting and protecting the infantry and supporting MCVs from air and missile
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