Disclosed is a propulsion system having a structural configuration that provides easy and convenient access to the interior regions of a liquid fuel tank and a hybrid rocket motor case. In one preferred form, when the water flow is turned on, the protective cover is hydraulically elevated or pops up to a raised position permitting substantially unimpeded projection of a water stream from the bubbler head for drinking, etc. The inner and outer pads may be rounded, feathered or otherwise configured to eliminate edges from the inner and outer pads, thereby preventing damage to adjacent components. The light emitting device package includes a plurality of metal layers disposed on the insulating layer. The processor may enable translating the graphical operations into programming code to be executed by a computer.