This left only the Sea Sparrow using the basic platform, and it no longer had to fit on aircraft. So instead of simply using the P and R models as they were, it was decided to dramatically upgrade the weapon as the Evolved Sea Sparrow. The ESSM emerged as a completely new weapon, common only in name with the original, although using all of the same support equipment allowing it to be fit to ships already mounting the older models. Compared to the Sea Sparrow, ESSM has a larger, more powerful rocket motor for increased range and agility, as well as upgraded aerodynamics using strakes and skid-to-turn. In addition, ESSM takes advantage of the latest missile guidance technology, with different versions for Aegis/AN/SPY-1, Sewaco/Active Phased Array Radar (APAR), and traditional target illumination all-the-way.