| All internal equipment that must be operated when the lunar exploration 
        base is not occupied by the crew must be designed to operate throughout 
        the "Unoccupied" temperature requirement. Equipment operated 
        only when the crew is present must meet the "Occupied" requirement. About Requirements and Specifications:  Requirements and specifications are always open for analysis and modification. 
        Whether we accept change to a requirement depends on the impact of the 
        suggested change. In general, though, the requirements should be as easy 
        as possible to meet while providing a useable spacecraft. Over-specified requirements lead to high costs and waste. |