The NSPO also used the M series upgrade as an opportunity to upgrade the system to allow it to be launched from a Vertical Launching System (VLS). This modification uses the "Jet Vane Control" (JVC) package that is added to the bottom of the missile. On launch, a small engine in the JVC boosts the missile up above the launching ship, then uses vanes positioned in its own exhaust to quickly slew the missile into the proper alignment with the target, which is fed to the JVC during launch. As far as the Sea Sparrow is concerned, there is no difference between being launched directly from a trainable launcher or using JVC, in both cases the missile becomes active looking directly at the target.