According to the former Italian President Francesco Cossiga, Italy's plans of retaliation during the Cold War consisted in dropping nuclear bombs against Czechoslovakia and Hungary in case of a first strike of the Soviets against NATO members.[19] He acknowledged the presence of U.S. nuclear weapons in Italy, and speculated about the possible presence of British and French nuclear weapons.[20] Italy secretly developed its own nuclear weapons program, and one in collaboration with France and Germany, but abandoned such projects when it joined the nuclear sharing program.[21][22] The country has developed the ABM PAAMS system.[23] It has developed several space-launch vehicles such as Alfa and more recently Vega. In more recent years, under the auspices of European space agency, it has demonstrated the reentry and landing of a spacecraft, the Intermediate eXperimental Vehicle. Italy is home of one of two ground operations centres of the Galileo global satellite navigation system.