Both Voyager 1 and 2 are displayed above (Images: NASA).
The NASA/JPL Voyager Satellite Program actively controls these two satellites. Launched in 1977, they are at the present moment the farthest known, still working man-made objects to ever travel across our Solar System. Please enjoy the link provided!
Special Note: The first artificial satellite to complete an orbital circuit around our planet was Sputnik 1, on October 4, 1957. This date marks the beginning of what is classically referred to as the Space Age. :-]