Missions Made by the United States

Name of Missions	Launch Date	Days To Mars	Comments and Discoveries
Mariner 3	November 5, 1964	Failed	Solar panels did not open,
Mariner 4	November 28, 1964	270	It returned more than 20 photos and it also analyzed the atmospheric composition.
Mariner 6	February 24, 1969	156	Took measurements of surface and atmospheric temperatures as well as taking over 200 images.
Mariner 7	March 27, 1969	128	Took measurements of surface and atmospheric temperatures, as well as taking 126 images.
Mariner 8	May 8, 1971	Failed	Failed to reach Earth orbit.
Mariner 9	May 30, 1971	167	The first Mars orbiter. It also took the first hi-resolution images of Phobos and Deimos. Returned 7329 images
Viking 1 Orbiter / Lander	August 20, 1975	303	The Viking 1 spacecraft was successfully delivered and deployed. The lander studied the Martian weather and biology. The orbiter mapped the surface.
Viking 2 Orbiter / Lander	September 9, 1975	333	The Viking 2 spacecraft was successfully delivered and deployed. The lander did important experiments on surface biology. The orbiter mapped the surface.
Mars Observer	September 25, 1992	Failed	Communication was lost.
Mars Global Surveyor	November 7, 1996	300	The Global Surveyor copies the design of the observer. It is is currently in the process of mapping the surface of Mars in the greatest detail ever.
Mars Pathfinder	December 1996	215	Pathfinder studies the surface composition and landscape.