Have Ground Launched Small Diameter Bombs Been ‘Thrown Aside’ By Ukraine?

A senior Pentagon official has alluded to a recently deployed long-range ground-launched weapon suffering from Russian jamming and other issues.

byJoseph Trevithick|
A senior U.S. official has strongly implied that Ground Launched Small Diameter Bombs sent to Ukraine have performed so poorly for a variety of reasons that they have been removed from service.


A U.S.-supplied air-to-ground munition transformed into a ground-based strike weapon has been performing very poorly in Ukraine due to jamming and other factors, according to a senior Pentagon official. Though the weapon system in question has not yet been confirmed, there are strong indications that it could be the Ground Launched Small Diameter Bomb (GLSDB).

"One company, I won't say who they are, they came up with a really cool idea of taking an air-to-ground weapon and doing a ground-launched version of it, and it would be a long-range fire weapon," Bill LaPlante, Under Secretary of Defense for Acquisition and Sustainment, said yesterday. The Under Secretary was speaking as part of a panel discussion at the annual Global Security Forum hosted by the Center for Strategic and International Studies (CSIS) think tank's International Security Program.

A scale model of a complete GLSDB round. Joseph Trevithick

Though not named, GLSDB is the only weapon system Ukraine is known to have gotten from the United States that matches LaPlante's complete description. The U.S. military has also supplied its Ukrainian counterparts with ground-launched laser-guided 70mm Advanced Precision Kill Weapon System II (APKWS II) rockets, which were originally designed for air-to-ground use, but these are not long-range munitions. There is the possibility that LaPlante was referring to a weapon system that has not yet been publicly disclosed. The War Zone has reached out to the Pentagon for more information.

GLSDB combines the GBU-39/B Small Diameter Bomb, a precision-guided glide bomb originally designed to be dropped from aircraft, with a 227mm rocket motor. This allows SDBs to be fired from ground-based launchers like the M142 High Mobility Artillery Rocket System (HIMARS) and the M270 Multiple Launch Rocket System (MLRS), examples of which Ukrainian forces have received from the United States and other countries. SDBs have GPS-assisted guidance packages and are only capable of striking static targets. You can read more about GLSDB and its capabilities here.

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U.S. aerospace firm Boeing developed GLSDB in cooperation with Saab in Sweden. For Ukraine, the biggest immediate benefit of the weapon was long expected to be its stated maximum range of approximately 94 miles (150 kilometers). The weapon also has the ability to make use of that range to take more circuitous routes to its target, allowing it to strike from unexpected vectors and otherwise present additional challenges for defenders.

Regardless, GLSDB offers significantly longer reach than the 50-mile maximum range of the 227mm guided rockets currently available for use with the M142 and M270 launchers. Those launchers can also fire Army Tactical Missile System (ATACMS) short-range ballistic missiles. Different versions of ATACMS have different maximum ranges, but they all have longer reach than GLSDB. Ukraine has reportedly received multiple versions of ATACMS now, as well as precision-guided 227mm rockets.

"They raced and did it as fast as they could," LaPlante continued in his remarks yesterday. He added that U.S. authorities truncated typical testing requirements to help speed the weapon system in question to Ukraine. Previous reporting has said that months of testing were still required before the GLSDBs could go to Ukraine. The weapons are not currently in U.S. military service.

"We said, look, just test for safety. Otherwise the operational testing will be non-cooperative with the Russians," according to LaPlante. "And so then we sent it to Ukrainians. It didn't work."

"It didn't work for multiple reasons, including [the] EMI [electromagnetic interference] environment, including just really ... doing it on [the] ground, the TTPs [tactics, techniques, and procedures], the DOTML [the doctrine, organization, training, and materiel] – it just didn't work," LaPlante explained. "And what happens is, when you send something to people in the fight of their lives, [and] it doesn't work, they'll try it three times and then they just throw it aside. So that's happened, too."

LaPlante's relevant remarks during the panel discussion at Global Security Forum 2024 begin at around 53:20 in the runtime of the video below.

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Though LaPlante did not elaborate on the EMI issues, there have now long been reports that Russian GPS jamming, in particular, has been impeding Ukraine's use of Western precision-guided ground and air-launched munitions. As the conflict in Ukraine has dragged on, Russian forces have significantly expanded their use of various tiers of electronic warfare capabilities, with another particular focus being on neutralizing first-person view (FPV) kamikaze drones and other armed uncrewed aerial systems.

However, LaPlante's comments point to many more factors beyond just EMI being at play. It is interesting to note here that the Pentagon's official factsheet on aid for Ukraine pointedly lists "Ground-Launched Small Diameter Bomb launchers and guided rockets" separately from "High Mobility Artillery Rocket Systems and ammunition." Whether or not this means that the GLSDBs were delivered to Ukraine along with bespoke launchers of some kind is unknown. GLSDB has been test-fired from a containerized launcher in the past.

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It is also worth remembering that the U.S. government first publicly pledged to send GLSDBs to Ukraine in February 2023 and their first reported use in combat did not come for another year. At the time of writing, no pictures or videos of these weapons being launched appear to have emerged and there does not look to be any definitive imagery of them hitting their targets. A video showing the remains of one of these weapons that was recovered in Ukraine seems to be the only real evidence of their use to date.

Though there are no clear indications one way or another that the two things are directly linked, LaPlante's remarks yesterday also came amid the disclosure that the U.S. military had sent another tranche of ATACMS missiles to Ukraine just last month. Despite the reported GPS interference from Russia, Ukrainian forces have, by all accounts, been using HIMARS and MLRS launchers to good effect when firing 227mm precision-guided rockets and ATACMS – both of which also use GPS-assisted guidance.

If LaPlante was indeed referring to GLSDB in his comments yesterday and those weapons have proven to be especially vulnerable to Russian GPS jamming, this could have broader implications. SDBs are in U.S. inventory in their air-launched form in very large quantities and are also in service with a significant number of countries around the world. The U.S. has the ability to increase the power of encrypted GPS over certain areas, but whether that could overcome such an issue is unknown.

Hopefully more details about GLSDB's use, or lack thereof, will now emerge following LaPlante's comments, but as it sits now we know that at least some long-range ground-launched weapon just isn't up to snuff on the battlefield in Ukraine.

Contact the author: joe@twz.com