With winter approaching, Ukrainian officials are in need of additional air defenses to protect their power grids from potential Russian strikes that could leave the country in darkness. To meet this need, they have turned to a weapons system known as the FrankenSAM program, which was originally developed by Ukraine and is now being pursued by the Pentagon. This program combines advanced Western-caliber surface-to-air missiles with refurbished Soviet-era launchers or radars that Ukrainian forces already possess. Various iterations of these improvised air defenses have been tested in the United States over the past few months and are set to be delivered to Ukraine this fall. The goal of the FrankenSAM program is to fill critical gaps in Ukraine’s air defenses and address the country’s most pressing challenge.

Ukraine has a history of successfully integrating offensive weapons from its Soviet-era stockpiles with those received from the West. This ability to “MacGyver” their arsenal has been praised by American military officials. Now, the FrankenSAMs project aims to do the same for Ukraine’s air defenses. The West has been supplying Ukraine with various air defense systems over the past 20 months, including Patriot and IRIS-T systems, tanks with antiaircraft guns, and Stinger missiles. Germany has also announced its intention to provide Ukraine with additional air defenses as part of a “winter package” worth nearly $1.5 billion.

The FrankenSAMs program is a combination of both existing systems and new weapons. The project originated when Ukrainian officials sought missiles for their unused Buk launchers and radars. Instead of obtaining Russian-manufactured munitions, they proposed retrofitting the launchers to use NATO-caliber antiaircraft missiles provided by the United States. American engineers took over the work, causing a delay of more than seven months. The first few refurbished Buk launchers and missiles have only recently arrived in Ukraine. The older Hawk systems, which were initially pledged by Spain, also required additional time to become operational.

Other FrankenSAM variants include an improvised ground launcher that uses Soviet-era radars to fire American Sidewinder missiles, and a Patriot missile system that operates with Ukraine’s older radar systems. These systems are still undergoing testing, but the Patriot missile system is scheduled to be sent to Ukraine this winter. Defense experts have praised the integration of Soviet-era equipment with advanced Western missiles as a way for Ukraine to maintain its arsenal and make use of weapons that are currently not in active use by NATO countries.