Eurosam is a Franco-Italian joint venture created by the French companies Aerospatiale and Thompson-CSF and the Italian firm Alenia/Finmeccanica in order to develop the anti-missile programme FSAF (Future Surface-to-Air Family), which is organised around the Franco-Italian missile Aster.

This family has a naval component, the PAAMS (Horizon program) and a mobile land component to be mounted on vehicles which is currently under development.

The two versions of the missile differ only in the size of their first booster stage and, consequently, their range: from 1.7 to 30 km in the case of the Aster 15, and from three to 80 km in the case of the Aster 30.

The Aster is capable of load limits of 60 G in its terminal phase thanks to its aerodynamic pilot, in addition to which there are impulses from lateral jets at the centre of gravity, making last-minute corrections of trajectory possible at the moment of interception. That capability makes the Aster unique in the world.

Aster is capable of evolving in the direction of an antiballistic role in the future. The missile would be able to deal with ballistic missiles with a range of 1,000 km as they re-enter the atmosphere. The homing head would have to be made more powerful or its algorithms speeded up, considering the approach speeds involved. The field of the proximity fuse would have to be reduced from 60o to 30o to increase its sensitivity, and fragmentation of the explosive charge would have to be adjusted to produce larger fragments.

The Principal Anti-Air Missile System (PAAMS) is a new surface-to-air missile system, developed essentially to provide medium-range air defence and anti-missile protection for high-value units, such as aircraft carriers or merchant tankers, in the vicinity of the escort. The Horizon air defence frigate project involves France, Italy and the United Kingdom. The missile will be called the Sea Viper in UK service.

The program covers the ship and secondary weapon systems, and PAAMS. the PAAMS has not suffered from London's recent decision to withdraw from the Horizon frigates program. The Horizon International Joint Venture Co., the prime contractor designated for the program, is owned by the French firm Direction des Constructions Navales (DCN) International, the British firm GEC-Maritime Ltd., and the Italian company Orrizonte SpA.