History: NASA Archive Photography

The first successful landing on Mars was made by Viking I in 1976. 20 years later a rover was landed on Mars by Mars Pathfinder.
Outside Mars, Jupiter was first visited by Pioneer 10 in 1973. More than 20 years later Galileo sent a probe into the planets’ atmosphere. The first spacecraft to leave the solar system was Pioneer 10 in 1983. At a time it was the most distant spacecraft, but it is now passed by Voyager 2.
Both the Pioneer and the Voyager program carries messages from the Earth to extraterrestrial life. A problem with far space travel is communication. For instance, at present it takes about 3 hours for a radio signal to reach the New Horizon spacecraft at a point more than half way to Pluto. Contact with Pioneer 10 was lost in 2003.
On 26 November 2011, NASA's Mars Science Laboratory mission was successfully launched for Mars. The mission is scheduled to land the robotic "Curiosity" rover on the surface of Mars in August 2012, whereupon the rover will search for evidence of past or present life on Mars.