Common Extensible Cryogenic Engine

How can a rocket engine that generates 5000 degree steam and 13800 pounds of thrust form icicles at the rim of its nozzle? It's cryogenic. The Common Extensible Cryogenic Engine, CECE for short, has completed its third round of intensive testing. This technology development engine is fueled by a mixture of -297 degree Fahrenheit liquid oxygen and -423 Fahrenheit liquid hydrogen. The engine components are super-cooled to similar low temperatures. As CECE burns its frigid fuels, gas composed of hot steam is p