It seems hard to believe, but since the 1960's humans have been sending spacecraft to Mars. The earliest pioneers were the robotic vehicles of the Soviet Union in 1960 and 1962 - but these faced a host of teething problems, from launch failures to communication failures en route to the red planet.
In 1964 NASA's Mariner 4 became humanity's first successful mission to Mars, returning images that immediately laid to rest most of our speculations about this world being any kind of Earth-analog. Mars was dry, dusty, well-cratered, and very alien.
Recently NASA posted the following video montage of all (successful) Mars missions the agency has undertaken, as well as a glimpse to the future. It's naturally rather self-congratulatory, but hey, if you can explore another world with this degree of skill I think you're allowed a little bit of celebration. And in this era of political uncertainty it doesn't hurt to remind us all of what you can do for a tiny fraction of the US GDP.
The universe is out there, let's go look.
(Credit: NASA, JPL, Caltech)