The universe is vast and expansive. It is so incredibly large that the human mind is incapable of understanding its true size. It is the most hostile environment imaginable. Extreme temperatures, lack of atmosphere, and intense radiation make space a dangerous place for both human beings and machines to explore. But in spite of this danger, the universe is being explored. From the time of the first telescope to modern day spacecraft and space probes, space exploration has a long and fascinating history.

"Exploration is in our nature. We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars."

— Carl Sagan, Astronomer