F-104S.ASA-M "9-42" at Pratica di Mare AB May 30, 2004

The "new" F-104 was called S because it was designed to carry and fire the AIM-7E Sparrow BVR missiles.
By the way, two main versions of the F-104S were finally made: the interceptor variant (CI) and the strike variant (CB).

The F-104S/CI had a FIAR/NASARR F15G radar capable to guide the Sparrow missiles. The missile's guidance system was quite large and it was accommodated in the space used for the gun in the F-104G.
So the CI was only armed with a maximum combination of 2 Sparrows and 4 Sidewinders. Theoretically it was a great improvement over the 2 Sidewinder of the G, 
by the way the need to carry auxiliary fuel (to the inboard pylons) tanks and the impossibility to use the ventral pylons (just as it was for Italian F-104G)
limited the CI maximum armament to 2 Sidewinder to the tips and 2 Sparrows to the outboard pylons.
During QRA duty F-104S/CI were usually lighter and standard configuration was just 1 sidewinder and 1 Sparrow and tip tanks. F-104S/CI also had no central underbelly pylon.
by Pierpaolo Maglio

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