Iran is in the midst of a multi-year plan that it hopes will culminate in the production of several hundred missile launchers and over 1,000 long-range ballistic missiles within the next six years, according to estimates in the Israeli defense establishment. Teheran is believed to currently have an arsenal of 100-200 long-range Shihab missiles that have a range of up to 2,000 kilometers and carry up to one-ton warheads. In addition, the Iranians last year test-fired a missile called Ashura believed to have recently entered production, the goal being to eventually replace the Shihab. The Ashura is a solid-fuel missile, giving it a long shelf-life. Unlike the Shihab, it does not need to be fueled shortly before launching. According to Israeli estimates, Iran's plan is to obtain 500 missile launchers and over 1,000 missiles with a range of 2,500 km. by 2015. "The Iranians are making great efforts to obtain a significant number of missiles," said Tal Inbar, head of the Space Research Center at the Fisher Brothers Institute in Herzliya. "They already talk about how one of the ways they will overcome the missile defense systems is by firing salvos of missiles." Inbar said that Iran was likely digging missile silos throughout the country that could be used to launch the Ashura solid-fuel missile. In addition, regular trucks carrying hydraulic launchers could be manufactured in Iran and used as portable launchers, capable of firing from anywhere in the country. According to estimates in Israel, Russia is still considering supplying the S-300 air defense system to Iran but is waiting to see what happens with the dialogue that the United States plans to hold with Iran. Depending on the outcome of the dialogue and the status of relations between Washington and Moscow at the time, Russia will decide whether it will supply the system to Iran. The S-300 is one of the most advanced multi-target anti-aircraft-missile systems in the world, with a reported ability to track up to 100 targets simultaneously while engaging up to 12 at the same time. It has a range of about 200 kilometers and can hit targets at altitudes of 90,000 feet. On Monday, the IAF will hold a countrywide exercise that the military stressed was not connected to current events. The exercise will include the IAF's reserve forces and the public, should not be alarmed if it hears sirens and notices increased activity in Israel's skies, the army said.