According to SpaceX's website, the Grasshopper program is -
... a critical step toward achieving SpaceX's goal of developing fully and rapidly reusable rockets. With Grasshopper, SpaceX engineers are testing the technology that would allow a launched rocket to land intact, rather than burning up upon reentry to Earth's atmosphere.It wouldn't be a real stretch of the imagination to see how perfecting this sort of technology would also enhance the capabilities of future systems designed for manned missions to either the Moon or Mars.The rocket looks and functions like something science fiction fans have been familiar with for a long time.
