Exploration of Mars
The Viking program launched "Viking 1" and "Viking 2" spacecraft to Mars in 1975; The program consisted of two orbiters and two landers – these were the first two spacecraft to successfully land and operate on Mars.
The primary scientific objectives of the lander mission were to search for biosignatures and observe meteorologic, seismic and magnetic properties of Mars. The results of the biological experiments on board the Viking landers remain inconclusive, with a reanalysis of the Viking data published in 2012 suggesting signs of microbial life on Mars.
The Viking orbiters revealed that large floods of water carved deep valleys, eroded grooves into bedrock, and traveled thousands of kilometers. Areas of branched streams, in the southern hemisphere, suggest that rain once fell.
Apollo (spacecraft)
The Apollo Lunar Module was a separate vehicle designed to land on the Moon and return to lunar orbit, and was the first true "spaceship" since it flew solely in the vacuum of space. It consisted of a "descent stage" and an "ascent stage". It supplied life support systems for two astronauts for up to four to five days on the Apollo 15, 16 and 17 missions. The spacecraft was designed and manufactured by the Grumman Aircraft Company.