@uçuyorum ,
Please don’t be misguided by trick explanations and descriptions regarding rocket stages.
If you do not take in to account the booster section, Siper Block 1 also has a single stage rocket engine.
Dual pulse (using the fuel tank in two stages) or dual thrust (using two different burn-speed fuels) rocket engines are all single stage missile engines..
Siper Block 2 should still have a dual thrust or dual pulse engine. US uses dual thrust on SM 2 block 4 and ESSM , to give
boost-and-sustain characteristics to the flight of the missile. You need a dual action engine to achieve good thrust to catch incoming threats, especially at or just before terminal stage, and eliminate them. For their latest AIM260-JATM air to air missile, the Americans are expected to be using a dual pulse engine; where as all their previous Aim series have used a dual thrust engine.
I like those fins at the bottom open up as it leaves the canister. Something says it could be quad packable??