• JDAM satellite-guided bombs provided to Ukraine are missing their targets.
• First used in Afghanistan, the bombs home in on coordinates with the help of GPS signals, greatly boosting accuracy.
• Russia has considerable experience with anti-GPS techniques, including protecting President Vladimir Putin, himself.

American-made satellite-guided bombs provided to Ukraine are missing their targets. These Joint Direct Attack Munitions (JDAMs)—which use a strap-on kit that turns ordinary aerial bombs into precision-guided weapons—have repeatedly failed in the field, falling victim to Russian electronic-warfare jamming.

Battlefield Improvisation

Over the past year, the United States and Ukraine have been working together to bring advanced American weapons to the Ukrainian Air Force’s aging fighter jets. In September 2022, Ukraine’s air force surprised the world when it revealed that it was using American-made AGM-88 High-Speed Anti-Radiation Missiles (HARMs), launched from MiG-29 and Su-27 fighters to attack Russian air-defense radars. The HARMS, used to attack Russian air-defense radars, helped Ukrainian jets and helicopters move a little more safely near an extremely dangerous front line.

In December, the U.S. government took a further step, announcing it would send JDAM satellite-guided bombs to Ukraine. Guided by GPS satellite signals, the bombs were supposed to provide Ukraine with a quick and easy precision-guided aerial bomb capability. Now, four months later, the U.S. government believes that the bombs are falling victim to Russian jamming efforts, according to Politico.

Directed Attack

The Joint Direct Attack Munition is a brilliant example of using new technology to make older, more primitive weapons better. JDAM is actually a kit that includes a GPS receiver, computer brain, and maneuverable bomb fins. The kit is strapped onto inexpensive, unguided bombs—including 500-pound Mk.-82, 1,000-pound Mk.-83, and 2,000-pound Mk.-84 bombs—and the end result is a precision-guided weapon system.

JDAM bombs are loaded onto planes like any other bomb. Once airborne, the pilot can enter the GPS coordinates of a target on the ground into the JDAM’s brain. The aircraft typically climbs to a fairly high altitude—the higher the aircraft, the farther the bomb can glide to a target—and then releases the JDAM. The bomb then makes a beeline for the target coordinates, wiggling its fins to make course corrections as it free-falls through the air, typically striking within 15 feet of the target.

That is, unless the JDAM is used in Ukraine.

Directed Meddling

According to leaked U.S. government documents, Ukrainian JDAMs are missing their targets. The problem also extends to guided rockets, a reference to the GMLRS rockets that M142 HIMARS rocket trucks launch. The leaked information blames Russian electronic-warfare efforts, particularly radio jamming, for the misses.

Russia is probably the preeminent world power in battlefield jamming. The Russian military has been acutely aware of the West’s use of precision-guided weapons, particularly satellite-guided ones, and has undertaken a considerable effort to nullify that advantage. Russia has led development of GPS jamming capabilities, and the Russian Armed Forces maintains five electronic-warfare brigades for battlefield jamming.

• How This Humble Drone Shrugs Off Russian Jamming

Russian GPS jamming is common within Russia, inside Russia’s neighboring countries, and where Russian forces operate abroad. In December 2022, Wired reported that GPS was being jammed inside Russian cities; this was in response to Ukrainian drones attacking Russian air bases inside Russia, itself, and was meant to confuse drones that used GPS to navigate to their targets. Russian GPS jamming in Syria, meant to protect military bases, creates service disruptions as far away as Turkey, Lebanon, Israel, and Cyprus. Local jamming even protected Russian President Vladimir Putin and his convoy from drone attack during a 2018 trip to Ukraine.

The situation probably unfolds something like this: a Ukrainian Air Force MiG pilot on a strike mission plugs in the GPS coordinates of a ground target into a JDAM bomb. As his plane nears the Russian front line, Russian air-defense radars detect his aircraft and alert nearby electronic-warfare units. The electronic warfare troops turn on their powerful Krasukha-4, Pole 21-E, or R-330Zh Zhitel jammers—which broadcast on the GPS frequency— brushing aside the satellite’s radio signals. The bomb, unable to use the GPS satellites above as a reference point for navigation, “goes dumb,” and misses the target.

Are We Missing Something?

JDAM bombs have a backup inertial navigation system (INS), one that is supposed to get the bomb to within 90 feet of the target about half of the time—not great, but not terrible. That should be enough to destroy non-hard targets like fuel and ammunition dumps, artillery, and other light armored vehicles and weapons, and still pose a danger to enemy infantry.

There are a few possibilities that would explain this. One is that the JDAMs are being used against armored targets that require direct hits, like tanks and bunkers, and INS is just not accurate enough to destroy them. Another possibility is that the porting of JDAM to Ukrainian fighters does not include the backup INS capability. Yet another possibility is that Ukrainian fighter jets are flying so low that the bombs, after losing GPS, lack the flight distance to issue the course corrections that will allow them to land close enough to their targets.

The Takeaway

Workarounds exist, like newer JDAM bombs that utilize both GPS and laser guidance, but Ukrainian fighters lack the necessary laser designators to make the system work. The U.S. and Ukraine now need a new weapon—or figure out how to destroy the jammers. Russia has invested heavily in technologies meant to deny key U.S. capabilities, and the investment is paying off.