Since the launch of Sputnik 1 in 1957, humans have been putting more and more elaborate and technically sophisticated probes and satellites into space. The last thirty years has seen tremendous developments in terms of the technology used in space exploration—solid fuels, solar panels, and radioactive power sources are just some of the remarkable innovations that have allowed space agencies across the planet to tackle evermore ambitious missions that would once have never been thought possible. So now that we’ve explored most of our solar system with fearless, pioneering space robots, it’s time to pick out which ones are our favorites.
10. Deep Impact
Like Rosetta-Philae, Deep Impact was another spacecraft sent to gather information about speeding comets. However, rather than attempting to land on one, Deep Impact’s mission was to smash an “impactor” into the comet Tempel 1. Why, you might ask? Well, scientists pretty much just wanted to see what would happen. Prior to this mission they had never had a firm grasp on what the physical composition of a comet was like. Deep Impact was the first experiment to probe beneath the surface of a comet. The instruments onboard the spacecraft, along with ground-based telescopes and space-based observatories, recorded the impact and examined the resulting debris and interior material. The mission has greatly advanced our understanding of comets and provided a wealth of data that will take years to fully interpret.
http://apod.nasa.gov/apod/ap050516.html Source: Apod.nasa.gov