STERN
(Static Test of Expansion/Deflection Nozzle)

Reaction Engines is involved with the University of Bristol and Airborne Engineering in the STERN project. This has the objective of testing a full hot firing rocket engine with a special type of nozzle called an Expansion/Deflection Nozzle to validate the small scale experiments and computer modelling work done by Dr Neil Taylor at the University of Bristol.

The project was proposed by REL’s MD Alan Bond over coffee at the March 2007 UK Space Conference at Charterhouse as part general discussions between the partners. Progress was very rapid; the engine had been built and the first firing conducted in time to be reported at the following UK Space Conference in March 2008.

The engine uses air and hydrogen as propellants to match the mixture in the SABRE whilst in air-breathing mode. Indeed the injectors and igniter are the design intended for SABRE. It has proved a very successful programme with three firing campaigns each extending the instrumentation to get further valuable insights into its operation.

There is much more detail on the Project STERN website : www.projectstern.co.uk

or watch the Project Stern Video

The STRICT engine is a follow on to the STERN project and involves the same team. It has the more ambitious goal of running the engine for longer by water cooling the combustion chamber. By cooling bits of the engine separately and monitoring the heat absorbed by the water, the temperature distribution in the engine can be established and compared with the theoretical modelling.

The STRICT project has only just started and the basic parameters like thrust have still to be established. The project will start with a series of small test nozzles to establish the exact design; this might be an Expansion/Deflection Nozzle like STERN or a dual bell where one nozzle shape using a low altitude with high atmospheric pressure becomes a second nozzle when in low pressure and vacuum environments.