This may explain why new missiles are not being purchased in large numbers right now, and why a number of new weapons have been and still are being cancelled--like the Sraw, the Tow-FF and the Trigat-MR--and why no decision regarding their replacement has yet been envisaged.
The Tow-FF (Tube-launched, Optically engaged, WireLESS Fire & Forget) derivative eliminates the wire and adds an imaging infrared focal-plane array seeker.