The capabilities of the new Sea Slug Mk 2, an almost 2.5 ton missile, were much improved compared to the previous Mk 1. The boosters gave a total of about 60 tons-force, with fuel for each one (145 kg in the Mk 1), accelerating it to over Mach 2. When they separated because the extreme drag made by the rings all around the missile, the solid fuel sustainer "Deerhound" started to burn its of propellant (390 kg for the Mk 1) and gave about for 38 seconds. The slender missile remained at over Mach 2-2.5 until the flameout. The missile was made fully controllable about ten seconds after firing, followed by a radio-beacon while it was centered in the radar beam; and armed the proxy fuse (infra-red) at about from the target, if 'hot', while if 'cold' the missile was detonated by command sent from the ship.