Space exploration is usually considered to be something of interest only to space scientists who can use the information obtained to test different theories of how the universe was created, how life started, and the alike. These have little, if any, practical application in the lives of millions of people who contribute to the funding of very expensive space exploration missions.
This is true to a large extent, after all why would someone have billions spent to determine if there is oxygen present on the moon of a planet in another stellar system when the same funds could be used to finance research and find a cure for diseases that affect and kill a large number of people, or to develop cleaner energy sources, etc.
An advantage of space exploration is the large number of spin-offs that have resulted from research done during space exploration missions. Some examples of these include scratch resistant lenses, invisible braces, shoe insoles, memory foam, various applications in long distance communication, hi-tech material that are widely used in automobiles, etc. These would have been difficult to obtain had it not been for the huge budgets allocated for space exploration missions.