The Air Force has now armed its F-15E with the Stormbreaker air-dropped bomb, a data link-enabled weapon able to track and destroy moving enemy targets from distances as far as forty nautical miles. In development for many years, the bomb is armed with several targeting innovations to include the use of a “tri-mode” seeker using millimeter wave, infrared and laser technology to track and destroy enemies.
Stormbreaker’s “tri-mode” seeker brings what might be a lesser recognized advantage, such as an ability to operate as a countermeasure of a certain kind. Given that commanders and pilots will have several different targeting modes to choose from depending upon mission variables, the range of options also enables alternative weapons guidance systems to be used in the event that one is “blocked” or “jammed.”
The various targeting modes built into the seeker create an important tactical “redundancy” which maximizes attack options in a wide range of warfare scenarios, therefore introducing added potential to thwart, overcome or counter various enemy countermeasures. This is a key part of the rationale upon which the Stormbreaker was engineered, as it has inertial measurement technology, GPS and radio data links such as LINK 16. The concept is to enable multiple modes of navigation and guidance technology so that the weapon can sustain functionality in a GPS-denied environment.
Perhaps a group of enemy armored vehicles on the move decide to intentionally maneuver under heavy cloud cover or during a sandstorm in the desert to make surveillance and laser targeting more complicated or even impossible? Weather obscurants can cause line-of-sight challenges and contribute to laser beam attenuation. In that scenario, a pilot attacking with Stormbreaker could choose an all-weather millimeter wave targeting mode or using millimeter wave radar and heat-seeking infrared mode to follow the heat signatures coming from the engines of enemy vehicles.
“The millimeter wave radar turns on first. Then the data link gives it a cue and tells the seeker where to open up and look. Then, the weapon can turn on its IR (infrared) which uses heat seeking technology,” a Raytheon weapons developer told The National Interest in a previous interview about Stormbreaker.
Millimeter wave technology, increasingly being woven into weapons guidance systems, is defined as small wavelengths with frequency ranges between 30 and 300 GHz where a total of around 250 GHz bandwidths are available, according to ScienceDirect. As with other kinds of radar, the higher the frequency, the more precisely configured the return signal, a technical phenomenon which can enable a munition to alter course upon detecting movement or position changes.
“The small wavelengths of mmWave frequencies enable large numbers of antenna elements to be deployed in the same form factor thereby providing high spatial processing gains,” as stated in a 2017 publication called “mmWave Massive MIMO, a Paradigm for 5G.” (Mumatz, Rodriguez, Dai)
Millimeter wave frequencies are often used to detect explosives on human beings because the small, ultra high frequency electromagnetic signals pass through human clothing, in a manner somewhat similar to how mmWave signals might pass through thick fog, sand or snow obscurants likely to obstruct detection. Engineering millimeter wave transmitting elements in a small enough form factor such that they can integrate into the Stormbreaker constitutes one of the innovations fundamental to the weapon.
What this amounts to is that building three different targeting technologies into a single network-enabled weapon multiplies attack options, therefore functioning as a countermeasure should an enemy seek various tactical measures to avoid being hit from the air. The Stormbreaker will also arm the F/A-18 and F-35.
Kris Osborn is the new Defense Editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.