Spacecraft with mixed rocket and jet propulsion.
Some numbers from the description (in german) on the 3-view :
Thrust : 1500 kp
Span : 4m
Length : 5,2m
Flight time : 11,5min
Max speed : 900 km/h
Source : "DER FLIEGER" January 1968
3-view plan by Karl Stöckel : https://cdn1.imggmi.com/uploads/2018/5/26/f8606d8f2ca980d4d55fabd7869f7b82-full.jpg