Ukrainian Air Force is set to field a new class of long-range weapons — air-launched cruise missiles grouped under the common name ERAM. As we previously explained, this designation covers two separate systems: the RAACM from CoAspire and the Rusty Dagger from Zone 5 Technologies.
The appeal of ERAM lies in its relatively low cost (up to $246,200 per missile) combined with long-range capability. Yet that naturally raises the key question: can these missiles remain effective under russian electronic warfare? Ukraine already has negative experience with the GLSDB, which was designed to strike targets at 150 km but proved vulnerable to russian jamming of its satellite navigation modules.
Read more: U.S. Approves $825 Million Sale of ERAM Cruise Missiles to Ukraine
This time, however, everything suggests the problem has been addressed beforehand. First, both ERAM designs were from the get-go required to maintain 10-meter accuracy in contested electronic warfare conditions. Secondly, the U.S. Defense Security Cooperation Agency's approval for Ukraine to purchase 3,350 ERAM missiles revealed a few interesting details about their guidance components.
"The Government of Ukraine has requested to buy up to three thousand three hundred fifty (3,350) Extended Range Attack Munition (ERAM) missiles and three thousand three hundred fifty (3,350) Embedded Global Positioning System (GPS)/Inertial Navigation Systems (INS) (EGI) with Selective Availability Anti-Spoofing Module (SAASM), Y-Code, or M-Code," reads the DSCA media release.
In practice, this means both ERAM variants use navigation systems equipped with SAASM. The thing is, GPS satellites broadcast separate signals for civilian and military users, with the latter secured through encrypted codes — the older Y-code and the newer M-code.
SAASM modules allow receivers to decrypt these signals using keys that are frequently updated. Any signal lacking the correct key is ignored, making spoofing virtually impossible without breaking the encryption.
While little is publicly known about the M-code, it is confirmed that GPS satellites launched since 2018 carry directional antennas that beam signals hundreds of kilometers across, with power levels up to 100 times stronger than standard GPS. Jamming such powerful directed signals becomes an extremely difficult task.
On top of that, ERAMs are not reliant on GPS alone. Both incorporate inertial navigation units, which calculate position independently and compare it against satellite data; if discrepancies appear, the system assumes GPS data was compromised.
The Rusty Dagger reportedly carries an additional autonomous navigation system and terrain-matching capability.
Analyzing the RAACM, we can also see two radar-transparent "windows" in its nose. The upper one is likely used for satellite navigation, while the lower one could house a TERCOM sensor for terrain-contour matching.
Altogether, the RAACM and Rusty Dagger appear designed with layered guidance systems to make sure that russian high-power electronic warfare systems become one of their targets, not an obstacle.
Read more: Ukraine to Receive Brand New U.S. Weapon, the ERAM: Capabilities and Pitfalls
