A compliment made by my superior in a performance review was "He thinks like a molecule of Mercury. I was designing and developing a closed Rankine Cycle power generation system for a satellite. The working fluid was Mercury and the environment was a zero gravity orbit. The power output was delivered by a turbine powered generator. The waste heat was rejected to space. Boiling, super-heating, condensing, collecting and pumping Mercury at zero G's was a aero/thermodynamic challenge. Everything was hidden in completely sealed stainless steal components and plumbing. For example: boiling Mercury forms liquid droplets in vapor instead of vapor droplets in liquid. Wetting agents were added to enable the required heat transfer in the boiler. Magnetic detectable floats were used to define Mercury state and distribution. The objective was to convert heat from a reactor or isotope heat source into electrical power. Sodium, Potassium, Rubidium, Sulphur and NaK were all considered as working fluids for similar power generation systems. There was no choice but to think like a particle.
