“Engine failure modes are minimized by eliminating separate subsystems where appropriate. For example, the first-stage thrust vector control system pulls from the high-pressure rocket-grade kerosene system, rather than using a separate hydraulic fluid and pressurization system. Using fuel as the hydraulic fluid eliminates potential failures associated with a separate hydraulic system and with the depletion of hydraulic fluid.”
Falcon 9 Launch Vehicle Payload User’s Guide, 2015
This is a clear sign that SpaceX is applying Principle 6 – Universality, to the design of its rockets.
Thrust vector control is a key component in flight control and in the unique tail-first landings that the SpaceX rocket stages achieve.
Your turn
What are you working on? Can a component of your service or system be applied in two ways, mimicking SpaceX and its use of high pressure fuel as hydraulic fluid?