The P4 high-altitude simulation test stand was built between 1963 and 1966. Since then, it has been rebuilt and extended several times. The attached high-altitude simulation facility allows the entire flight phase of an upper stage engine to be tested under space conditions.
The ability to test engines under real conditions in a vacuum has been with DLR Lampoldshausen since the 1960s. The need to develop, qualify and deploy propulsion systems under actual flight conditions at high-altitudes with a fully expanded jet flow defines the key performance characteristics for the test facilities. To this end, there are various test facilities for testing satellite engines, upper stage engines and mobile altitude simulation systems.
High-altitude systems offer the advantage of the following features in particular:
Testing the transient phases during ignition,
Combustion and re-ignition,
Testing throttleable engines
Testing new high-expansion nozzles, new nozzle geometries and materials
