Ground Launched Small Diameter Bomb (GLSDB)

NMaude said:
Long overdue! Anyway I hope the US DoD orders something similar with the SDB-II as since it has a seeker it can be used against moving targets.
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SDB-II is more complicated to use .... you need to provide target info (templates, characteristics) for its seeker to do matching and tracking ....
 
NMaude said:
Long overdue! Anyway I hope the US DoD orders something similar with the SDB-II as since it has a seeker it can be used against moving targets.
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SDB2 is Raytheon-made, not Boeing, and needs a different interstage adapter due to different shape tailcone.
 
NMaude said:
I'm aware of that and given how the GLSDB has performed so far I can see the US Do9D signing a contract with Raytheon to develop an adaptor compatible with the SDB-II.
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Gotcha!

And yes, I definitely see the DoD dropping a contract with Raytheon for GLSDB2s.

Edit: Frankly, Raytheon would likely be wise to throw some company money at making that interstage without a contract...
 
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Has there been any recent news concerning the GLSDB in Ukraine or in general? I wonder if the US DoD is considering doing a version using the SDB II instead?
 
NMaude said:
Has there been any recent news concerning the GLSDB in Ukraine or in general? I wonder if the US DoD is considering doing a version using the SDB II instead?
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The US military has expressed no interest in any version of GLSDB, as far as I am aware. ER GMLRS achieves the same range and is already in procurement.
 
TomS said:
The US military has expressed no interest in any version of GLSDB
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Maybe not the US military however there are certainly foreign customers who're users of the M142 and/or the M270 who'd definitely use it, Ukraine for example would love to have such a system.

Scott Kenny said:
GL-SDB2 has sensors and targeting capabilities that ER GMLRS does not have.
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This! For one thing the SDB2 can be used to attack moving targets as it has a terminal homing seeker.
 
Scott Kenny said:
SDB2 has a completely different tail shape.
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I'm aware of that, that's why I mentioned adapting the adaptor to mate with an SDB2.

Scott Kenny said:
And good luck getting Boeing to design something for a Raytheon product.
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Does Boeing make the adaptor or does SAAB? If it's the latter it shouldn't be an issue. But given the success of the limited use of the GLSDB in Ukraine so far I could see the US DOD finally take official interest in the missile and perhaps do a dual-source contract with Boeing and Raytheon in regards to the adaptor section.

On another note wouldn't the SDB1's launcher lugs be removed from the GLSDB variant as not only aren't they needed they add drag to its' airframe. Also what about encapsulating the SDB1 with a clamshell fairing (With an ogival nose) to extend the GLSDB's range by reducing drag, the clamshell fairing would split and seperate just before the adaptor unclamps and releases the SDB1.
 
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Scott Kenny said:
It can engage moving targets like TELs in all weather. TEL for anything within range is now fair game, even if it's on the move after the shot revealed the TEL location.

If the Russians don't have any TELs for (missile type) they can't fire any more. No matter how many (missile type) they have in stockpiles.
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If you know where a TEL is, just fire at at it. If you don't, why are you firing artillery in the first place?

SBD-2 is a much more expensive weapon with a lot more flexibility that is not useful in an artillery deployment. More over, if no one is interested in ground launched SBD-1, it hard to imagine anyone is interested in the dramatically more expensive version.
 
NMaude said:
It could also be used against ships too.
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Technically yes, practically an SDB would fall inside the engagement envelope of everything from 20mm to 100mm to every single SAM a ship carried. So it seems like a poor use of such.
 
Josh_TN said:
If you know where a TEL is, just fire at at it. If you don't, why are you firing artillery in the first place?
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The advantage is that SDB2 can be told "there was a TEL *here*, so sweep south-to-north up this road till you find it or run out of airspeed."

And IIRC you can watch the video as the Stormbreaker goes it via datalink.


Josh_TN said:
SBD-2 is a much more expensive weapon with a lot more flexibility that is not useful in an artillery deployment. More over, if no one is interested in ground launched SBD-1, it hard to imagine anyone is interested in the dramatically more expensive version.
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The ability to hit moving targets is a much under-rated thing.
 
Josh_TN said:
Technically yes, practically an SDB would fall inside the engagement envelope of everything from 20mm to 100mm to every single SAM a ship carried. So it seems like a poor use of such.
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It would be a very difficult object to target given its small size and no doubt could be programmed to take evasive manoeuvres in its terminal phase.
 
Scott Kenny said:
The ability to hit moving targets is a much under-rated thing.
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Even with a very short engagement time (from detection to fire order to munition arriving in the target area) you'd struggle to get an SDB2 (or even for that matter a powered Spear) over the target in time if it was moving, particularly as the MMW radar has limited search range (particularly for a gliding weapon that is attempting to manage energy and prolong a glide). Basically by the time the munition arrived the target could have moved out of its MMW range, and in the case of SDB2 its possible MMW range AND flight time for a search. And when the munition costs >$250k per round thats a real issue....(and some FMS cases are >$500k per round...).

The UK is looking at Land Precision Strike, basically a larger Asraam missile shape with Brimstone seeker head for engagements against fixed and moving targets from M270. The range on that is >80km, and the missile will be much faster to target as well...I think that is realistically the limit at present. The proposed P3 missile from c20 years ago was a similar range. The longer ranged LRAE which dispenses a package of 3 x Outrider UAS from a GMLRS-ER for search/detection and re-broadcast, followed by 3 x FFLMM from a follow on munition could extend moving target capability out to 150km+...but it will come at some cost...and I'm not sure it will proceed past a demonstration.
 
Scott Kenny said:
The advantage is that SDB2 can be told "there was a TEL *here*, so sweep south-to-north up this road till you find it or run out of airspeed."

And IIRC you can watch the video as the Stormbreaker goes it via datalink.



The ability to hit moving targets is a much under-rated thing.
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If you just get to the target faster you do not have to concern yourself with movement. Gliders are going to take an almost order of magnitude more time to go down range.

GBU-53 can receive link 16; I am not sure if it can transmit. Even if so that has nothing to do with sending full motion video, though it could perhaps send a notification that it had found a target and was about to hit it like the most recent HARMs.
 
What appears to be not good news about GLSDB (I think we have to assume that is what is being talked about).

https://twitter.com/x/status/1783514363841630309
View: https://twitter.com/John_A_Ridge/status/1783514363841630309?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Etweet


Youtube
Talks about Harpoon deployment in Ukraine. The European Nations would presumably be the UK and Denmark. Seems to imply that the un-mothballed Danish Harpoon launch systems were not in fact used (maybe they weren't available) and instead it was a more jury rigged system (which sounds like the UK may have been involved given their history with the Excalibur Exocet system).

Then (presumably) about GLSDB. Which surely should mean the USAF would be worried? Or is it something else?

View: https://www.youtube.com/live/L8IBwse5sgQ?si=2M7qzGLYSzQauOHE&t=3152
 
TTPs? Just give it time, I suspect the Ukrainians will make the GLSDB work and don't forget that they're actively looking for and destroying GPS jammers also I think that they should push the US DoD to develop and GLSDB2 variant.
 
If the GLSDB has been having problems in Ukraine due to Russian GPS jammers then Boeing needs to get onto the case (Although the Ukrainians I do believe are actively hunting and destroying these jammers whenever they can), perhaps the US DoD needs to look at a ground launched SDB2 variant as it has a terminal homing seeker.
 
The U.S. has no interest in rocket launched SDB, because it has aircraft to deliver SDB. It was always a solution in search of a problem from a U.S. standpoint. GMLRS-ER is the U.S. army solution, because it’s faster.

It is unsurprising that a glide bomb with no terminal homing has issues with Russian defenses.
 
Note his comments that if something doesn't work fairly quickly in combat, it gets put aside. Sounds like GLSDB may have been sidelined. If it's not effective, why risk the launcher?
 
If anything I'd say the Ukrainians don't have enough GLSDBs, however with the recently approved aid bill by the US Congress (I do believe that president Biden has signed it into law) maybe Ukraine will be getting a lot more of them soon.

On another note I wonder if the US DoD has an official designation for the GLSDB?
 
Josh_TN said:
The U.S. has no interest in rocket launched SDB, because it has aircraft to deliver SDB. It was always a solution in search of a problem from a U.S. standpoint. GMLRS-ER is the U.S. army solution, because it’s faster.

It is unsurprising that a glide bomb with no terminal homing has issues with Russian defenses.
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Thats true. But....SDB is one of the principal US air to surface munitions, and if it is adversely affected by GPS jamming they have a problem for the aircraft deployed weapons as well...
 
Strange that only 1 GPS weapon seems to be affected. Are GPS guidance systems really that varied across the military?
 
Forest Green said:
Strange that only 1 GPS weapon seems to be affected. Are GPS guidance systems really that varied across the military?
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In short yes. SDB1 does not use M-Code GPS, although there are plans apparently to retrofit it/place it on new production. SDB1 is ultimately designed as a cheap weapon. The placement of the antenna may make it more susceptible to jamming of GPS compared to the antenna placement on GMLRS for example.

JDAM has reportedly had issues with GPS denial in Ukraine. The ATCMS seen to date are INS only and do not use GPS. Paveway IV supplied by the UK does use M-Code GPS so should be less affected than JDAM (comes at a price though....PWIV is 3 times as expensive as basic JDAM).
 
timmymagic said:
In short yes. SDB1 does not use M-Code GPS, although there are plans apparently to retrofit it/place it on new production. SDB1 is ultimately designed as a cheap weapon. The placement of the antenna may make it more susceptible to jamming of GPS compared to the antenna placement on GMLRS for example.

JDAM has reportedly had issues with GPS denial in Ukraine. The ATCMS seen to date are INS only and do not use GPS. Paveway IV supplied by the UK does use M-Code GPS so should be less affected than JDAM (comes at a price though....PWIV is 3 times as expensive as basic JDAM).
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What system does AASM use? That seems to work alright based on a few videos anyway.
 
Forest Green said:
What system does AASM use? That seems to work alright based on a few videos anyway.
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AASM uses GPS/INS but also has Semi Active Laser and IIR homing heads available.

Like the name suggests its modular so you can have different configurations: GPS/INS and SAL, GPS/INS and IIR. Rocket booster on the 250kg one as well, to be honest I'm not sure if its been qualified on the 1000kg version, though to be fair we've only seen the 250kg version in Ukraine.

Comes at a cost though...Paveway IV might be 3 times the cost of basic JDAM....AASM is 3 times the cost of Paveway IV...
 
timmymagic said:
In short yes. SDB1 does not use M-Code GPS, although there are plans apparently to retrofit it/place it on new production. SDB1 is ultimately designed as a cheap weapon. The placement of the antenna may make it more susceptible to jamming of GPS compared to the antenna placement on GMLRS for example.

JDAM has reportedly had issues with GPS denial in Ukraine. The ATCMS seen to date are INS only and do not use GPS. Paveway IV supplied by the UK does use M-Code GPS so should be less affected than JDAM (comes at a price though....PWIV is 3 times as expensive as basic JDAM).
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It is worth noting M code is not yet enabled in the GPS constellation. That said, there are jam resistant antennas mounted on some weapons (SABR-Y).

I suspect part of the problem is the long glide out phase of the weapon, which allows more time to shoot it down and more time for its INS to drift. This is not an active weapon system for any other military; it was thrown together for Ukraine because the U.S. Army wasn’t interested.
 
Josh_TN said:
I suspect part of the problem is the long glide out phase of the weapon, which allows more time to shoot it down and more time for its INS to drift. This is not an active weapon system for any other military; it was thrown together for Ukraine because the U.S. Army wasn’t interested.
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It wasn't thrown together though...it was first test fired 9 years ago after lots of work by Boeing and Saab.

As for the glide? Its going to be pushed out to at least 40 miles by the M26 rocket before release, it will be released at a higher altitude (believe M26 hits around 46,000ft at perigee) than most SDB are dropped from aircraft and will be travelling faster as well. Unless its going out to the maximum range that it can reach its glide profile is likely to be better than an air dropped SDB, faster and from a higher altitude. Sure if you go for an ultra long range shot it will be long and flat, but it will still start from a higher altitude and from a much higher speed.
 
timmymagic said:
In short yes. SDB1 does not use M-Code GPS, although there are plans apparently to retrofit it/place it on new production. SDB1 is ultimately designed as a cheap weapon. The placement of the antenna may make it more susceptible to jamming of GPS compared to the antenna placement on GMLRS for example.

JDAM has reportedly had issues with GPS denial in Ukraine. The ATCMS seen to date are INS only and do not use GPS. Paveway IV supplied by the UK does use M-Code GPS so should be less affected than JDAM (comes at a price though....PWIV is 3 times as expensive as basic JDAM).
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So does GMLRS and ATACMS use M-Code because they still seem to work?
 
Josh_TN said:
No. Some versions of ATACMs do not even use GPS. GMLRS will use M code in future builds but older rockets do no have the feature and again, M code is not active yet doue to problems with the ground segment.
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Strange that SDB would have problems then, because I see videos of GMLRS hitting the actual EW stations all day long. I'm thinking that the bulk of the problems may be non-jamming related.
 
timmymagic said:
It wasn't thrown together though...it was first test fired 9 years ago after lots of work by Boeing and Saab.

As for the glide? Its going to be pushed out to at least 40 miles by the M26 rocket before release, it will be released at a higher altitude (believe M26 hits around 46,000ft at perigee) than most SDB are dropped from aircraft and will be travelling faster as well. Unless its going out to the maximum range that it can reach its glide profile is likely to be better than an air dropped SDB, faster and from a higher altitude. Sure if you go for an ultra long range shot it will be long and flat, but it will still start from a higher altitude and from a much higher speed.
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Well it never entered production. There is no line to produce it so these first examples are probably more or less pre-production samples.

40 miles sounds a little generous for the original version of the rocket; that is the GMLRS range. The cluster bomb rockets I believe had shorter range.

In any case, it will have a long, subsonic fly out from high altitude to achieve its maximum range compared to an aeroballistic missile like ATACMs. That will introduce more vulnerability.
 
Forest Green said:
Strange that SDB would have problems then, because I see videos of GMLRS hitting the actual EW stations all day long. I'm thinking that the bulk of the problems may be non-jamming related.
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Pentagon said HIMARS rockets had also been struggling in GPS denied environments and we know JDAM also failed to be effective in Ukraine and was pulled. I am seeing some suggestions that the reason European GPS guided weapons are handling the electronic warfare environment but US ones arent is the Boeing GPS Antenna's arent up to snuff. BAE has recently been winning a lot of orders for its GPS guidance kit in the US.
 
WatcherZero said:
Pentagon said HIMARS rockets had also been struggling in GPS denied environments and we know JDAM also failed to be effective in Ukraine and was pulled. I am seeing some suggestions that the reason European GPS guided weapons are handling the electronic warfare environment but US ones arent is the Boeing GPS Antenna's arent up to snuff. BAE has recently been winning a lot of orders for its GPS guidance kit in the US.
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Interesting, I still see HIMARS working well in videos though, GL-SDB I've only seen one from memory, 2 for AASM.
 
WatcherZero said:
Possibly depends on age of munitions, been varying improved marks over the years as well as different FCS software in the launchers.
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The above. Different vintages of GPS guidance have different levels of vulnerability. Also GPS jamming likely forces most weapons to fall back to INS guidance at some point in flight, and INS guidance might also have varying degrees of accuracy. Jamming is not typically going to make a missile or bomb go wild; it is going to degrade the accuracy. So different weapons will have different levels of effectiveness and likely only be incrementally degraded, though projectiles with the smallest explosive load will likely be more affected, all other things equal.
 

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