The United States plans to send Ukraine some Soviet-era missile defense equipment that Washington requisitioned decades ago, according to U.S. officials who spoke to The Wall Street Journal. The air defense systems were acquired through a secret program designed to help the U.S. government understand Russian capabilities. The clandestine arsenal was first publicly revealed in 1994, and is part of a project reported to have cost the U.S. more than $100 million. The systems will be familiar to the Ukrainians, as the same type of equipment fell into their military’s hands after the fall of the Soviet Union. Among the equipment expected to be provided to Ukraine is the SA-8 short-range surface-to-air missile system, which is highly mobile, according to the Journal. The Pentagon has assessed that Russian forces have fired more than 1,100 missiles into Ukraine since the invasion began nearly a month ago. The U.S. is banking on providing enough equipment to help Ukraine create its own no-fly zone, without direct NATO interference that might risk escalating the conflict.