A rocket engine suitable for using for an educational program uses a liquid phase propellant (102A) having a predetermined boiling point and a heating substance (102B) having a temperature higher than the boiling point. The engine has an inner wall (103B) ...

The present invention provides a solid polymer electrolyte fuel cell comprising a fuel cell stack (21) formed by laminating a plurality of fuel cell units each of which includes a fuel electrode (23), an oxidant electrode (24), and a solid polymer electrol...