How JDAM ‘Smart Bombs’ Could Help Ukraine Smash Frontline Targets With Eerie Precision (2024)

• The Pentagon is preparing to send Joint Direct Attack Munition (JDAM) weapons to arm Ukraine’s air force.
• JDAM is a kit that turns ordinary, dumb bombs into satellite-steered weapons with great accuracy.
• Despite falling equipment stockpiles, the Pentagon believes JDAM weapons would be less useful in a war against China, making it easier to part ways with them.

The United States government is preparing to send satellite-guided bombs to bolster Ukrainian forces. The Joint Direct Attack Munition (JDAM) uses navigation data from GPS satellites to slam targets within 15 feet of the aiming point. In use since the late 1990s, the weapon will be somewhat easy for the Pentagon to give up as it lacks the standoff capabilities required for a potential war with China.

According to The Washington Post, the Pentagon is planning to include JDAM guidance kits in an upcoming tranche of aid to Ukraine. The Post quoted multiple senior officials who were familiar with the matter; it’s not clear whether the Biden Administration approved the transfer of JDAMs.

What Is the Joint Direct Attack Munition?

The Joint Direct Attack Munition is actually a kit that modifies regular dumb, free-fall bombs into precision weapons. The U.S. military—including the Air Force, Navy, and Marines—have traditionally relied on the 500-pound MK.-82 bomb, 1,000-pound MK.-83 bomb, and 2,000-pound MK.-84 bomb. These bombs are cheap, but unguided, and although powerful, can easily miss their targets.

✅ Joint Direct Attack Munition: By the Numbers

• Range: Up to 15 miles
• Ceiling: 45,000+ feet
• Unit cost: About $22,000 per tail kit (in 2007 dollars)
• Projected total inventory: 217,746 (149,237 U.S. Air Force, 68,509 U.S. Navy)

Source: U.S. Air Force

JDAM kits include a GPS seeker, inertial navigation system, and a strap-on set of tail fins. The kit can be easily installed on all three types of bombs within minutes, radically transforming the bomb from one that has no guidance capability into a weapon capable of accuracy within 15 feet.

JDAM changed the way precision-guided munitions were used. Laser-guided weapons— which first appeared toward the end of the Vietnam War—introduced near-pinpoint accuracy, but had one flaw: the bomb required a laser pointed at the target for the entire time it was in flight. This often meant that the aircraft dropping the bomb, armed with a laser designator, had to continue to fly more or less toward the target until the bomb made contact. Some laser designators were mounted in a turret that allowed a plane to turn away from the target, but still required the plane to have the target in more or less its forward hemisphere. A pilot could not, for example, do a quick 180-degree turn to avoid air-defense fire.

However, JDAM makes that possible. A pilot programs the target’s GPS coordinates into the bomb and releases it, enabling the aircraft to turn quickly away from the target. The bomb flies through the air, using its tail fins to adjust its course, while taking its navigation cues from the constellation of Global Positioning System satellites in medium-Earth orbit. The bomb continues to do this until it impacts the target on the ground.

JDAMs also allow air crews to service multiple targets in a single bomb run. An aircraft is only equipped with one laser that can only “paint” one target at a time; multiple targets will require multiple runs. An aircraft armed with multiple JDAMs can launch all of them at once, each assigned to attack a different target. In 2011, three B-2 stealth bombers loaded with JDAMs attacked 45 targets at the Ghardabiya military airfield in Libya. Each B-2 attacked 15 hardened aircraft hangars and other targets in a single pass, each JDAM striking its target with a high level of accuracy.

Delivering JDAMs to Ukraine

For the past 20+ years, JDAMs have been used in Afghanistan, Iraq, Libya, and other conflict zones. Their time as the go-to weapon in the U.S. arsenal is coming to an end, however: JDAMs have a limited range—15 miles at most—placing the launching aircraft well within the range of modern air defenses deployed by countries like Russia and China.

Newer, longer-range weapons, like the Joint Air-to-Surface Standoff Missile, can strike with the same level of accuracy from hundreds of miles away. The Stormbreaker guided bomb, a direct descendant of JDAM, incorporates pop-out fins to allow the bomb to glide up to 46 miles before hitting its target. While JDAM will remain a cheap alternative for dropping munitions on adversaries without credible air defenses, the U.S. is winding down its participation in such conflicts, making the JDAM less necessary.

The U.S. and its allies typically use the JDAM on American-made fighters and attack aircraft. Ukraine, on the other hand, flies older, Cold War-era Su-27 (NATO code name: “Flanker”) air superiority fighters, MiG-29 “Fulcrum” multi-role fighters, and Su-25 “Frogfoot” fighters whose ordnance rails are fitted to carry Soviet-designed ordnance. However, an unknown number of Su-27s and MiG-29s have been modified with the American LAU-118 ordnance rails, which attach to BRU-32 (also American) bomb racks. These racks can accommodate JDAMs.

Another method for delivering JDAMs is the newly developed Ground-Launched Small Diameter Bomb. GLSDB is a 250-pound dumb bomb equipped with the JDAM guidance package and pop-out fins. It’s launched via rocket from an M142 HIMARS or M270 Multiple Launch Rocket System vehicle. GLSDB is similar to the conventional JDAM package, but has a range of about 100 miles. Defense contractor Boeing proposed the system for Ukraine, which already operates the M142 and M270. The U.S. does not actually use GLSDB, so there is no capability taken away from Pentagon war planners.

The United States has built up Ukraine with formidable capabilities. JDAM will allow Ukraine to destroy targets on the front line, resulting in the need for fewer quantities of other precision-guided munitions, like the GPS-guided Excalibur artillery shell. But, launched from the air, it will also expose Ukrainian Air Force jets lobbing the weapons to medium- and long-range air defenses. That is, if HIMARS doesn’t get them first.