Oscar Wilde once said, A man who knows the price of everything and the value of nothing. This is especially true of space exploration, the value would outweigh the cost at any price. Space exploration is helping us learn who we are and where we came from as a planet and specie. It is also closer than ever to showing us if there is other life or habitable planets. Putting a price limit on that kind of knowledge is a foolhardy idea.
Yes, exploring space is worth the cost involved. While it is sometimes difficult to quantify the contributions that space exploration has brought to society, some of the zero-gravity experiments in space have yielded product improvements back on Earth. The simple fact that humanity is able to explore space, though, is worth the expense -- particularly given some of the other things that governments spend money on.
Space exploration teaches us about what happens beyond our small world and what the laws of the universe are. However, it provides extraordinary value even beyond the development of science. Space exploration does not have to do with our everyday life. Therefore, it teaches people to look beyond themselves. It is a glorious way of showing what man can be and how far he can go. There is no better way to prove the greatness of humankind than a man stepping beyond his small world and demanding to know everything that can be known. Space exploration is a huge factor in making people dream big and reach for the stars.
Space exploration is valuable in that it helps us understand how life is able to exist on earth through the study of why it can't exist on other heavenly bodies within our solar system. Additionally, a great deal of our knowledge of time and weather patterns has come from space exploration. Understanding how our planet fits into our solar system may ultimately help us resolve problems here on earth, which makes it a valuable expense.
Some people did not make it to space like the Challenger and Columbia also there is so much more stuff that is important like health and education and food people need this stuff you don't need to spend money on people going to space spend it on people with diseases instead.