Since the beginning of the space age there have been 17 landings on the surface of Mars, some of which were not successful. Initially the Soviet Union carried out two attempted landings in 1971, Mars 2 and 3, but the first lander crashed and the second returned only 20 seconds of data before failing on the Martian surface. Regardless, these became the first human-built artifacts to reach the surface of Mars. Another landing attempt took place in 1973 when the Soviet Union dispatched Mars 7 to the red planet. It failed to rendezvous with Mars and went into a solar orbit without accomplishing its mission. A major contribution came in July 1976 with the successful landings of Viking 1 and 2 by the United States.
After the Vikings, despite other attempts, no other landers were successful in reaching the Martian surface until 1997 when Mars Pathfinder opened the modern age of Martian exploration. Thereafter, several additional landers have successfully made it to the surface of the red planet and have reshaped humanity’s understanding of this intriguing world.
Mars has proven a difficult place on which to land successfully. The box score for the record of landings is seven successes, ten failures. While it might be expected that landing failures would have been common early in the space age, greater success should come with time, experience, and more sophisticated technology. This is the case, certainly, but unfortunately in the last decade several Mars landing missions have also failed. Successfully reaching the surface of this planet has proven a task not without difficulties, yet the prize of scientific knowledge continues to spur significant efforts. There is no dearth of plans for continued exploration using landers, rovers, and flying machines that might operate in the thin Martian atmosphere. The following is a chronological list of all landing missions on Mars, along with their basic results.
- Mars 2 – USSR Mars Orbiter/Soft Lander – 4,650 kg – (19 May 1971): The Mars 2 lander was released from the orbiter on 27 November 1971. It crashed-landed because its breaking rockets failed – no data was returned and the first human artifact was created on Mars. (Lander unsuccessful)
- Mars 3 – USSR Mars Orbiter/Soft Lander – 4,643 kg – (28 May 1971): Mars 3 arrived at Mars on 2 December 1971. The lander was released and became the first successful landing on Mars. It failed after relaying 20 seconds of video data to the orbiter. (Lander unsuccessful)
- Mars 7 – USSR Mars Orbiter/Soft Lander – 4,650 kg – (9 August 1973): On 6 March 1974, Mars 7 failed to go into orbit about Mars and the lander missed the planet. Carrier and lander are now in a solar orbit. (Unsuccessful)
- Viking 1 – USA Mars Orbiter/Lander – 3,399 kg – (20 August 1975 – 7 August 1980): Viking 1 was launched from the Kennedy Space Center, on 20 August 1975, the trip to Mars and went into orbit about the planet on 19 June 1976. The lander touched down on 20 July 1976 on the western slopes of Chryse Planitia (Golden Plains). The lander had experiments to search for Martian micro-organism. The results of these experiments are still being debated. The lander provided detailed color panoramic views of the Martian terrain. It also monitored the Martian weather. The orbiter mapped the planet’s surface. The orbiter weighed 900 kg and the lander 600 kg. The Viking project’s primary mission ended on 15 November 1976, eleven days before Mars’ superior conjunction (its passage behind the Sun), although the Viking spacecraft continued to operate for six years after first reaching Mars. Viking 1 lander was accidentally shut down on 13 November 1982, and communication was never regained. Its last transmission reached Earth on 11 November 1982. Controllers at NASA’s Jet Propulsion Laboratory tried unsuccessfully for another six and one‑half months to regain contact with the lander, but finally closed down the overall mission on 21 May 1983. (Lander successful)
- Viking 2 – USA Mars Orbiter/Lander – 3,399 kg – (9 September 1975 – 25 July 1978): Viking 2 was launched for Mars on 9 November 1975, and landed on 3 September 1976. The orbiter weighed 900 kg and the lander 600 kg. The lander had experiments to search for Martian micro-organism. The results of these experiments are still being debated. The lander provided detailed color panoramic views of the Martian terrain. It also monitored the Martian weather. The orbiter mapped the planet’s surface, and, with its Viking 1 orbiter, acquired over 52,000 images. The Viking project’s primary mission ended on 15 November 1976, eleven days before Mars’ superior conjunction (its passage behind the Sun), although the Viking spacecraft continued to operate for six years after first reaching Mars. (Lander successful)
- Phobos 1 – USSR Mars Orbiter/Lander – 5,000 kg – (7 July 1988): Phobos 1 was sent to investigate the Martian moon Phobos. It was lost en route to Mars through a command error on 2 September 1988. (Unsuccessful)
- Phobos 2 – USSR Phobos Flyby/Lander – 5,000 kg – (12 July 1988): Phobos 2 arrived at Mars and was inserted into orbit on 30 January 1989. The orbiter moved within 800 kilometers of Phobos and then failed. The lander never made it to Phobos. (Lander Unsuccessful)
- Mars 8 – Russia Orbiter & Lander – 6,200 kg – (16 November 1996): Mars ’96 consisted of an orbiter, two landers, and two soil penetrators that were to reach the planet in September 1997. The rocket carring Mars 96 lifted off successfully, but as it entered orbit the rocket’s fourth stage ignited prematurely and sent the probe into a wild tumble. It crashed into the ocean somewhere between the Chilean coast and Easter Island. The spacecraft sank, carrying with it 270 grams of plutonium-238. (Unsuccessful)
- Mars Pathfinder – USA Lander & Surface Rover – 870 kg – (4 December 1996): The inexpensive Mars Pathfinder (costing only $267 million) landed on Mars on 4 July 1996, after its launch in December 1996. A small, 23-pound, six-wheeled robotic rover, named Sojourner, departed the main lander and began to record weather patterns, atmospheric opacity, and the chemical composition of rocks washed down into the Ares Vallis flood plain, an ancient outflow channel in Mars’ northern hemisphere. This vehicle completed its projected milestone 30-day mission on 3 August 1997, capturing far more data on the atmosphere, weather, and geology of Mars than scientists had expected. In all, the Pathfinder mission returned more than 1.2 gigabits (1.2 billion bits) of data and over 10,000 tantalizing pictures of the Martian landscape. The images from both craft were posted to the Internet, to which individuals turned for information about the mission more than 500 million times through the end of July. The mission’s primary objective is to demonstrate the feasibility of low-cost landings on the martian surface. This was the second mission in NASA’s low-cost Discovery series. (Successful)
- Mars Polar Lander – USA lander – 538 kg – (3 January 1999): and its attached Deep Space 2 probes were launched on a Delta II rocket which placed them into a low-Earth parking orbit. The third stage fired for 88 seconds to put the spacecraft into a Mars transfer trajectory. Trajectory correction maneuvers were performed on 21 January, 15 March, 1 September, 30 October, and 30 November 1999. After an 11-month hyperbolic transfer cruise, the Mars Polar Lander reached Mars on 3 December 1999. The lander was to make a direct entry into Mars’ atmosphere at 6.8 km/s but was lost during the landing sequence. JPL lost contact with the spacecraft and due to lack of communication, it is not known whether the probe followed the descent plan or was lost in some other manner. (Unsuccessful)
- Mars Express – European Space Agency (ESA) Mars orbiter and lander – 1123 kg – (2 June 2003): This Mars probe consisted of an orbiter, the Mars Express Orbiter, and a lander, Beagle 2. The scientific objectives of the Mars Express Orbiter were to obtain global high-resolution photo-geology (10 m resolution), mineralogical mapping (100 m resolution) and mapping of the atmospheric composition, study the subsurface structure, the global atmospheric circulation, and the interaction between the atmosphere and the subsurface, and the atmosphere and the interplanetary medium. The Beagle 2 lander objectives were to characterize the landing site geology, mineralogy, and geochemistry, the physical properties of the atmosphere and surface layers, collect data on Martian meteorology and climatology, and search for possible signatures of life. After launch on a Soyuz/Fregat rocket from Baikonur Cosmodrome, the orbiter released Beagle 2 on 19 December 2003. It coasted for five days after release and entered the Martian atmosphere on the morning of 25 December. Landing was expected to occur at about 02:54 UT on 25 December (9:54 p.m. EST 24 December). No signals have been received and the lander was declared lost. (Lander unsuccessful)
- Mars Exploration Rover A – USA Mars Rover – 827 kg – (10 June 2003): Named “Spirit” upon landing on the Martian surface on 4 January 2004 this rover was one of a pair launched to Mars in mid-2003. Equipped with a battery of scientific instruments it was intended to operate for 90 days, until April 2004, and to traverse about 100 meters a day. The scientific goals of the rover missions are to gather data to help determine if life ever arose on Mars, characterize the climate of Mars, characterize the geology of Mars, and prepare for human exploration of Mars. It has performed exceptionally well and is still operating in November 2007. A primary mission objective was to search for geological clues to the environmental conditions that existed when liquid water was present and assess whether those environments were conducive to life. It landed in Gusev Crater because it had the appearance of a crater lakebed. The rover’s scientific data suggests that Gusev may have at one time been filled with water. (Successful)
- Mars Exploration Rover B – USA Mars Rover – 827 kg – (7 July 2003): Named “Opportunity” upon landing on the Martian surface on 25 January 2004 this rover was the second of a pair launched to Mars in mid-2003. It carried identical instruments to “Spirit” and landed at Terra Meridiani, also known as the “Hematite Site” because it displays evidence of coarse-grained hematite, an iron-rich mineral which typically forms in water. This mission has also continued into November 2007. (Successful)
- Phoenix Mars Lander – USA Mars Lander – 350 kg – (4 August 2007): The Phoenix Mars Lander was designed to study the surface and near-surface environment of a landing site in the high northern area of Mars. The primary science objectives for Phoenix are to: determine polar climate and weather, interaction with the surface, and composition of the lower atmosphere around 70 degrees north for at least 90 sols; determine the atmospheric characteristics during descent through the atmosphere; characterize the geomorphology and active processes shaping the northern plains and the physical properties of the near-surface regolith focusing on the role of water; determine the aqueous mineralogy and chemistry as well as the adsorbed gases and organic content of the regolith; characterize the history of water, ice, and the polar climate and determine the past and present biological potential of the surface and subsurface environments. Phoenix was launched on 4 August 2007 on a Delta II 7925 from Cape Canaveral Air Force Station, Florida. The 681 million km heliocentric cruise to Mars took approximately 10 months, with landing on Mars on 25 May 2008. (Successful)
- Yinghuo-1 – Chinese Mars Orbiter – 115 kg – (8 November 2011): The primary scientific aims of the Orbiter were to study Martian environmental structure including plasma distribution, the solar-wind atmosphere coupling and energy distribution, the regional gravity field of Mars, and Martian surface imaging. In addition, the mission was to test deep space navigation and communication. It was to work with the Russian Phobos-Grunt, and be stacked on one of its common boosters. The Orbiter did not perform its scheduled burn to begin its trajectory to Mars. It will stay in orbit around the earth. Roscosmos is investigating what went wrong. (Unsuccessful).
- Phobos-Grunt (alternatively Fobos-Grunt) – Russian Spacecraft – 730 kg – (8 November 2011): This spacecraft was designed to land on Mar’s moon Phobos and return a sample to earth to be able to study its history and origin. This would focus on analyzing the material gathered and comparing it to Martian and other Solar System matter for similarities. It was supposed to carry the Chinese Mars Orbiter Yinghuo-1. Once launched into Earth’s orbit, the spacecraft was supposed to fire once again to begin an eleven month trajectory to Mars. These firings never happened, however, and the spacecraft reentered the atmosphere on January 15, 2012. (Unsuccessful).
- Mars Science Laboratory, “Curiosity,” (MSL) – USA Mars Rover – 750 kg – (26 November 2011). Launched at 10:02 EST, the objective of Curiosity was to explore the Martian Habitat as a former or current habitat for life, and as such, it would operate for a full Martian year, or 687 earth days. MSL has eight scientific objectives: determine the nature and inventory of organic compounds, inventory the chemical building blocks needed for life, identify features that reflect biological processes, investigate the Martian surface and near surface geological features, interpret the processes that have formed rocks and soils, assess long-timescale atmospheric evolution processes, determine the present state and distribution of water and carbon dioxide, and characterize the spectrum of surface radiation. After leaving Earth’s orbit, the Rover traveled eight months to reach Mars, landing on August 6, 2012. It has been incredibly successful in its science program. (Successful).