At the time of the moon landing in 1969, many people envisioned that by the beginning of the 21st century, space travel would become routine, and we would be visiting other planets in our solar system and perhaps even daring to venture into interstellar space.
Sadly, that future hasn't yet arrived. In fact, some people have started to question whether we need space travel anymore. Wasn't going to the moon good enough? Maybe the U.S. should leave space exploration to private companies -- or even other countries.
But those who've long dreamed of humans becoming a truly spacefaring race argue that exploring space provides down-to-earth benefits in areas such as health, mining and security. And more inspirational benefits, too. Here are some of the most compelling arguments for continuing the exploration of space.