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Ground Launched Small Diameter Bomb

Triton

Donald McKelvy
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Artist's impression of Boeing GL-SDB (Ground Launched Small Diameter Bomb).

Boeing is modifying the Small Diameter Bomb with a rocket motor to be launched from ground-based missile systems such as the M270 MLRS. After the motor launches it to a high enough altitude and speed, the wings will deploy and glide the bomb to its target. The company believes it can fill a gap for long-range precision fires. While typical MLRS systems follow a ballistic trajectory, the rocket-launched SDB can be launched to an altitude and glide on a selected trajectory. Boeing is planning on a demonstration in 2014.
Source:
http://defense-update.com/20121207_fire-support.html
http://en.wikipedia.org/wiki/Small_Diameter_Bomb#Ground-launched_SDB
 

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SpudmanWP

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Imagine these from a VL Mk41. Set them for a timed, simultaneous impact to overwhelm naval targets.

Using a mk41 would also allow for a longer motor which would give a longer range.
 

sferrin

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SpudmanWP said:
Imagine these from a VL Mk41. Set them for a timed, simultaneous impact to overwhelm naval targets.

Using a mk41 would also allow for a longer motor which would give a longer range.
Pretty tiny warhead to use against a ship.
 

bobbymike

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sferrin said:
SpudmanWP said:
Imagine these from a VL Mk41. Set them for a timed, simultaneous impact to overwhelm naval targets.

Using a mk41 would also allow for a longer motor which would give a longer range.
Pretty tiny warhead to use against a ship.

http://www.youtube.com/watch?v=RdKco9pWq4A
Bunker Buster SDB warhead type. Penetrating below decks take it out of action wouldn't sink an average size warship, however.
 

aim9xray

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SDB Warhead: about 250 pounds Cost: about $90,000
Harpoon Warhead: about 480 pounds Cost: about $1,200,000

(Your cost figures will vary - but this may yield some idea of the ROM costs per round...)
 

bobbymike

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aim9xray said:
SDB Warhead: about 250 pounds Cost: about $90,000
Harpoon Warhead: about 480 pounds Cost: about $1,200,000

(Your cost figures will vary - but this may yield some idea of the ROM costs per round...)
What would be the added cost of the rocket booster? The real comparison would be this vs an ATACMS

If we assume a 150km range a single launcher could control over 70,000 sq km of territory and hit anything that moves within that territory with great precision.

I wonder if you could scale it up to fulfill a short range precision munition need for the army. You could just have a bigger boosters and put a 2000lbs JDAM on it. To get a 2k JDAM to 150km would require what sized booster?

Imagine a special forces team in A-Stan needs to target a large cave or heavily fortified bunker. How much cheaper would it be to develop a HIMARS type mobile launcher as compared to needing a few F-16's or in the future F-35's nearby with all the logistics that entails to carry a 2000lbs class weapon?
 

SpudmanWP

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sferrin

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I wonder how much distance they could get out of one of these launched from an F-22. B)
 

Grey Havoc

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(Removed accidently included quote.)

A 'basic' GL-SDB would likely not be effective against mobile targets, land or sea.
 

bobbymike

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sferrin said:
I wonder how much distance they could get out of one of these launched from an F-22. B)
Ya no kidding, F-22 flying at 60k feet launches one of these, gets boosted to 100k feet and glides to the target. What's the SDB with wings glide ratio? I bet the range would be 500+km at least under this, however unlikely, scenario.
 

SpudmanWP

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Grey Havoc said:
A 'basic' GL-SDB would likely not be effective against mobile targets, land or sea.
That depends on the SDB model.

SDB1 can have a datalink added (not a good option)
LSDB can be designated from drones, aircraft, or surface craft (better)
SDB2 can do laser designation, MMW radar, or IIR for terminal guidance. (best option)

I think that they should take the idea of the LSDB and swap out the laser seeker with a LOGIR seeker and datalink.
 

Abraham Gubler

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bobbymike said:
Ya no kidding, F-22 flying at 60k feet launches one of these, gets boosted to 100k feet and glides to the target. What's the SDB with wings glide ratio? I bet the range would be 500+km at least under this, however unlikely, scenario.
I doubt an SDB would do much gliding at 100,000 feet. More like falling down to air thicker enough to have lift generated by its wing. Plus this is a big arse short duration burn rocket motor designed to launch the weight of a heavyweight boxer from ground level. It would have a significant IR signature if launched by a fighter and much of its impulse wasted generating drag. A much more sensible approach to boost range of the SDB would be something along the lings of the JSOW-ER. A low profile sustainer motor designed to counter height loss in the glider.
 

bobbymike

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Abraham Gubler said:
bobbymike said:
Ya no kidding, F-22 flying at 60k feet launches one of these, gets boosted to 100k feet and glides to the target. What's the SDB with wings glide ratio? I bet the range would be 500+km at least under this, however unlikely, scenario.
I doubt an SDB would do much gliding at 100,000 feet. More like falling down to air thicker enough to have lift generated by its wing. Plus this is a big arse short duration burn rocket motor designed to launch the weight of a heavyweight boxer from ground level. It would have a significant IR signature if launched by a fighter and much of its impulse wasted generating drag. A much more sensible approach to boost range of the SDB would be something along the lings of the JSOW-ER. A low profile sustainer motor designed to counter height loss in the glider.
How are they proposing to boost a scramjet to Mach 4-5 speeds? A big arse rocket motor? Plus my comment was more curiously theoretical than an endorsement of a future weapon system. :D
 

Abraham Gubler

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bobbymike said:
How are they proposing to boost a scramjet to Mach 4-5 speeds? A big arse rocket motor?
This has nothing to do with scramjets.

bobbymike said:
Plus my comment was more curiously theoretical than an endorsement of a future weapon system.
Your comment was:

bobbymike said:
Ya no kidding, F-22 flying at 60k feet launches one of these, gets boosted to 100k feet and glides to the target. What's the SDB with wings glide ratio? I bet the range would be 500+km at least under this, however unlikely, scenario.
Those last two sentences seem quite specific and less than theoretical. But that’s OK. This isn’t a court of enquiry. I’ve simply pointed out that the SDB is extremely unlikely to be able to glide at 100,000 feet.

Further one runs horses for courses. Boeing are talking about a surface launched application of the SDB. It has needs that are very different to boosting a glide bomb launched at altitude.
 

bobbymike

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Abraham Gubler said:
bobbymike said:
How are they proposing to boost a scramjet to Mach 4-5 speeds? A big arse rocket motor?
This has nothing to do with scramjets.

bobbymike said:
Plus my comment was more curiously theoretical than an endorsement of a future weapon system.
Your comment was:

bobbymike said:
Ya no kidding, F-22 flying at 60k feet launches one of these, gets boosted to 100k feet and glides to the target. What's the SDB with wings glide ratio? I bet the range would be 500+km at least under this, however unlikely, scenario.
Those last two sentences seem quite specific and less than theoretical. But that’s OK. This isn’t a court of enquiry. I’ve simply pointed out that the SDB is extremely unlikely to be able to glide at 100,000 feet.

Further one runs horses for courses. Boeing are talking about a surface launched application of the SDB. It has needs that are very different to boosting a glide bomb launched at altitude.
- I was simply responding to sferrin 'wondering' the range of an air launched weapon my original response was asking whether a ground based system could be 'upscaled' to a 2000lbs JDAM which in of itself was a response that an SDB has a pretty small warhead, anywho................

Yes I know this has nothing to do with a scramjet but your critique of my theoretical concept ;) concerned the IR signature of a big booster launched from an aircraft I was simply asking whether this is how they would launch a scramjet weapon inferring a rocket booster's IR signature does not seem to be a problem in that case.
 

Moose

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sferrin said:
SpudmanWP said:
Imagine these from a VL Mk41. Set them for a timed, simultaneous impact to overwhelm naval targets.

Using a mk41 would also allow for a longer motor which would give a longer range.
Pretty tiny warhead to use against a ship.
Depends on the size of the target. 250lbs would pretty easily ruin the day of low-end combatants.
 

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Found on http://memsense.com/articles/cdg-project

THOR - Enhanced Opportunity
Boeing and AMTEC recently proposed development/deployment of the Tactical High-agility Operations Rocket ("THOR") - a retrofitted M26 rocket that is glide configured and equipped for in-flight targeting. The THOR delivers range, accuracy and firepower comparable to the new XM31 GPS guided rocket, but at less than half the cost. A modified CDG is a system component for THOR.

Is THOR a today's GL-SDB?
 

bobbymike

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Boeing To Demonstrate Ground-Launched SDB System Later This Year


Posted: Feb. 20, 2014

Boeing is attempting to bring an Air Force solution to an Army problem by developing a ground-launched version of the Small Diameter Bomb it produces for the service's F-15 fighter aircraft, and the company will self-fund a test flight of that system later this year. By financing the demonstration, the company hopes the Army will see its Ground-Launched Small Diameter Bomb (GL-SDB) system as a viable replacement munition for the M270 Multiple-Launch Rocket System (MLRS), which currently employs a type of cluster munition being phased out by the Pentagon. In a Jan. 27 interview with Inside the Air Force, Jon Milner, Boeing's GL-SDB business development lead, said the SDB is currently employed on the Air Force's F-15 Strike Eagle as a 250-pound-class, air-to-ground munition, and it happens to also fit easily into the 200-pound-class MLRS launch pods. He said by coupling SDBs with the Army's stockpile of MLRS unguided M26 rocket motors, the bombs can be launched to great altitudes and glide to their targets rather than follow the normal point-to-point ballistic trajectory.

"The GL-SDB is an integration program, not a development from scratch," Milner said. "We've got in-production SDB mature technology, a combat-proven rocket motor and a combat-proven warhead. We're creating the adapter in between them, which we have confidence in." Milner said the company ground-tested the system last December and plans to complete the first flight test sometime in the third quarter of this year. Lockheed Martin is the prime system and munitions contractor for MLRS and is already ahead of Boeing in its development of a replacement munition. The company secured a $79.4 million contract with the Army in 2013 to develop and demonstrate a warhead to replace the current cluster munition, the dual-purpose improved conventional munition (DPICM). The Defense Department is planning to replace the legacy explosive in accordance with its policy on cluster munitions. This policy seeks to phase out all munitions with an unexploded ordnance rate higher than 1 percent by 2018, according to the text of a 2008 directive. In a Feb. 3 press release, Lockheed announced that it had successfully conducted its second production qualification test on its alternative warhead, which is a unitary submunition within the company's M30 guided rocket system.

Boeing's GL-SDB system is unconventional and is substantially different from the one being demonstrated by Lockheed, in that the warhead is guided instead of the rocket motor. "When you shoot a high angle you lose range, because of the higher quadrant," Milner said. "I can launch [GL-SDB] from any location, 360 degrees, because it's [global positioning system]-guided. Once the M26 rocket boosts it to altitude, the SDB acts like it was just released from an F-15 and it glides to wherever it's programmed to hit. It can go around the back side of mountains." Since 2005, Boeing has delivered more than 10,000 SDBs to the Air Force, and according to Milner the Army has more than 400,000 M26 rocket motors in its inventory which would otherwise be demilitarized. Boeing began investigating the system in 2010 in response to requests by engineers at the Army's Redstone Arsenal in Alabama who were looking for new uses for the Army's stockpile of M26 units, according to Milner. "The Small Diameter Bomb just happens to have roughly the same form factor, and if you stick it on top [of the M26] it still fits in the [MLRS] launch-pod container," Milner said. "It's an air-to-ground weapon we're trying to adapt for a ground-to-ground mission."

Boeing has taken its GL-SDB concept to the Pentagon and the Army, but neither is showing much interest in funding further development work -- which is why the company is internally funding its own testing. "In my opinion, what we're offering would be very appealing to the Army," Milne said. "From a budget standpoint, our projected cost would be almost 30 to 40 percent less than the current cost of [Lockheed's] guided MLRS. And if you cut us into the inventory, I think you'd have a cost savings. Depending on how the Army views its budget reality, we could be a very appealing system to them." The company is also eying international customers, but Milner would not say which ones. The MLRS is employed by a number U.S. allies. "It's a way to upgrade your MLRS inventory, achieve longer range, with more capability, for what we project to be a lower cost than buying a new guided MLRS munition which Lockheed Martin sells," Milner said. Any adoption of the GL-SBD system could shore up production of the Small Diameter Bomb well past the U.S. Air Force's current total force requirement of 24,000 units.

Once developed, the GL-SDB is expected to have a range of about 90 miles when launched to the optimal altitude of 40,000 feet. Once the main work of creating the M26 interstage adapter is complete, various types of SDBs can be employed including laser-guided and focused-lethality variants. Boeing's GL-SDB system is also part of an Army analysis of alternatives for the MLRS Army Tactical Missile System (ATACMS) -- a 500-pound-class, long-range, precision munition. Production of the ATACMS ceased in 2007, and that capability gap has so far been filled by air support. "They're re-looking at that because the Air Force doesn't have the aircraft to cover all those missions," Milner said. Separate from Boeing's SDB efforts, Raytheon is also currently developing a laser-guided, seeker-type SDB for the Air Force, known as the Small Diameter Bomb II, which will eventually replace Boeing's weapon. The company announced a successful flight test of that weapon system in October 2013. Although the F-15 is currently the only aircraft which employs the SDB (GBU-39B), the Air Force is planning integration work for the F-16, B-1, B-2, F-22 and F-35, according to the service's fact sheet. -- James Drew
 

TomS

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aim9xray said:
SDB Warhead: about 250 pounds Cost: about $90,000
Harpoon Warhead: about 480 pounds Cost: about $1,200,000

(Your cost figures will vary - but this may yield some idea of the ROM costs per round...)
Warhead weight figures may also vary. The SDB is not all warhead -- there's a lot of non-warhead weight in that 250-lb total. I'd compare the actual explosive payloads of the two systems:
SDB explosive weight: 38 pounds (17 kg)
Harpoon explosive weight: 215 pounds (98 kg)
Warhead weight is roughly twice this due to casings and fuzing.
 

Triton

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Published on Mar 20, 2015

At a test range in northern Sweden, Boeing and Saab tested the Ground Launched Small Diameter Bomb (GLSDB) by adapting the SDB to an artillery system. The GLSDB can reach targets from significantly longer distances, and engage hard-to-reach targets, while maintaining the Small Diameter Bomb’s flight maneuverability and accuracy.

https://youtu.be/kkkfE5yHejc
 

pathology_doc

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SpudmanWP said:
Imagine these from a VL Mk41. Set them for a timed, simultaneous impact to overwhelm naval targets.

Using a mk41 would also allow for a longer motor which would give a longer range.

I see an issue with flight time and target movement if used at long range, unless you update the trajectory. That being said, you wouldn't need more than a couple of hits to make even the largest surface combatant significantly less effective due to internal blast damage/fire. Aircraft carriers in particular would make juicy targets due to their large deck area and surfeit of soft, vulnerable, flammable items immediately beneath (even if the aircraft are not fully fuelled, there's always unusable fuel sloshing around at the bottom of the tanks). And even if your deck is tough enough to stop the bomb right there, you're surely going to get fire, local buckling and blast effect to anything nearby (aircraft, deck crew, radar superstructures, etc.) IIRC this was the rationale for giving the SBD Dauntless in its scout mode a 500lb bomb; even if it couldn't sink a carrier alone, it could make a hole in the deck and stop the carrier from launching a defensive scramble or a counter-strike before the follow-up attack group arrived to finish the job. This thing is far more effective than a WW2-vintage 500 pounder, and a carrier captain is going to have a nasty problem on his hands if any more than a couple of them hit him.


I'm thinking that a 1900-vintage protected cruiser, with its armoured deck and protective/sacrificial above-deck internal spaces, could take a hit from one of these and keep fighting. Modern ships, stuffed to the gills with essentials and with no armour or dead space to speak of, significantly less so - the only advantage the modern ship has is in the efficacy of its damage control measures.


It'd be sort of like Hedgehog for surface warships, albeit with a much heavier and more effective charge.
 

SpudmanWP

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Two items can make this even better:


1. Boeing has a kit for SDB1 (called LSDB) that will make it laser guided. It reuses the laser seeker from LJDAM (low cost).


2. If they do something similar to LSDB but reuse the LOGIR seeker (low-cost IIR seeker) then it can have some nice, long range moving target capabilities.





 

pathology_doc

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IIRC Sidewinder evolved from the concept of a cheap and easy guidance system for the Zuni 5" rocket. LOGIR seems to be the modern equivalent for its venerable little brother.


It's arguably what the F-86D always needed but could never have (aircraft with a much larger salvo of rockets perhaps less so, as mutual interference might lead the rockets to show greater fratricidal tendencies). B)
 

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http://nationalinterest.org/blog/the-buzz/the-us-armys-long-range-missiles-could-be-the-perfect-tool-18357
 

bobbymike

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http://www.defensenews.com/articles/army-pushes-long-range-precision-fires-development-plan-out-by-a-year

Again it seems to me a Superpower should be able to produce a 500km range missiles, in fact, a whole family of missiles from SRBM/IRBM/MMBM ranges in a much shorter time frame than this.
 

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bobbymike said:
http://www.defensenews.com/articles/army-pushes-long-range-precision-fires-development-plan-out-by-a-year

Again it seems to me a Superpower should be able to produce a 500km range missiles, in fact, a whole family of missiles from SRBM/IRBM/MMBM ranges in a much shorter time frame than this.
The DoD's way of getting stuff developed is deeply rotten, but many other countries are terrible at this as well (UK, Italy, Germany, India...).
The Israelis and Swedes seem to know how to do this better.
 

marauder2048

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bobbymike said:
http://www.defensenews.com/articles/army-pushes-long-range-precision-fires-development-plan-out-by-a-year

Again it seems to me a Superpower should be able to produce a 500km range missiles, in fact, a whole family of missiles from SRBM/IRBM/MMBM ranges in a much shorter time frame than this.
The complication here is the new, parallel development of ATACMS Blk II with
SCO's multi-mode seeker and warhead package along with the additional testing
and production cut-in of the height-of-burst sensor on the SLEP'ed TACMS.

Ideally, all of that should end up on LRPF but needs to be at the right maturity level.
 

marauder2048

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SpudmanWP said:
Two items can make this even better:


1. Boeing has a kit for SDB1 (called LSDB) that will make it laser guided. It reuses the laser seeker from LJDAM (low cost).
GLSDB’s long-range maneuvering capability proven to engage moving target at 100 km

The two companies have demonstrated GLSDB’s capabilities for ground forces during a test fire where the
laser-enabled weapon successfully launched and then tracked and engaged a moving target at a distance
of 100 kilometers. The demonstration was conducted in cooperation with the U.S. Army Aviation & Missile
Research, Development and Engineering Center (AMRDEC) in 2017. AMRDEC provides increased
responsiveness to warfighters through aviation and missile capabilities and life cycle engineering solutions.

“Ground forces in many countries are increasingly facing missions that require greater range, flexibility
and maneuverability,” said Görgen Johansson, head of Saab’s business area Dynamics. “GLSDB uses two
combat-proven systems that allow users to quickly engage both stationary and moving targets from any
angle at significant range.”

During the test fire, the Saab-Boeing team successfully launched a GLSDB, enabled with a semi-active laser
seeker, from a ground test location. The SDB and rocket motor separated at the necessary height, and the
weapon engaged the intended maritime target at approximately 100 kilometers away from the launch site,
using the SDB’s proven flight maneuverability capability.

...
https://saabgroup.com/media/news-press/news/2018-06/saab-and-boeing-to-feature-glsdb-at-eurosatory/
 

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sferrin

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It's been 3+ years since they first tested the concept. My question is, why isn't it already in service?
 

DrRansom

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Not "transformational" enough? Doesn't produce a "quantum-leap" to "technological-overmatch"? Alternatively, SDB could be Tor-bait. It is a relatively expensive weapon, especially SDB-II, and isn't survivable enough to be economical on a high-intensity battlefield.

To return to the first point. Not to go all historical, but the last time the US faced a peer enemy in the Soviet Union, the US had far from "technological-overmatch." If your opponent has an economy with a similar capability to yours, you cannot expect to beat them in all aspects of armed conflict. The dream that the US can maintain "technological-overmatch" is going to cripple weapons development until the US focuses on "overmatch" in the areas which count and focus on competitive and economical capabilities in other areas.
 

sferrin

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DrRansom said:
Not "transformational" enough? Doesn't produce a "quantum-leap" to "technological-overmatch"? Alternatively, SDB could be Tor-bait. It is a relatively expensive weapon, especially SDB-II, and isn't survivable enough to be economical on a high-intensity battlefield.
So far it's just SDB I, and there aren't enough TOR on the planet to defend everything. SDB on MLRS would be damn useful.
 

SpudmanWP

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They could easily be programmed to do a simultaneous impact pattern which would likely overwhelm any defenders.
 

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Saab will test its Ground-Launched Small Diameter Bomb (GLSDB) later this month, with officials hoping the flight will push the 140km mark for the first time.
The last time the system was fired, a 2017 test in the US, the distance reached was short of 100km. Reaching 140km in the latest test would represent close to maximum range for the system.

 
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