Head of a combustion chamber of an A4 rocket ("V2")

• Aluminium, brass, 1943-1945, height: 60 cm

Aggregat 4 (A4) is the type designation of the world's long-range guided ballistic missile with a liquid-propellant rocket engine. The ballistic ground-to-ground missile is developed in the German Reich at the Peenemünde Army Experimental Station on Usedom from 1939 under the leadership of Wernher von Braun and is deployed in large numbers in the Second World War as of 1944.

The correct mixing of fuel and oxidant is a basic problem for the performance of the rocket's liquid propulsion unit. The engine specialist Dr Walter Thiel solved this problem by introducing 18 pre-chambers ("pots") in which the components are swirled.