The crossword solution for the term SPACE OPENER is AERO, which is a four letter word. AERO is an abbreviation of aeronautics, which is the science of flight and the operation of aircraft. It is also used to refer to the aerospace industry, which is the industry that designs, manufactures, operates, and maintains aircraft. In this context, SPACE OPENER could refer to any type of aircraft or spacecraft that is used to open up SPACE exploration.