Exploration of Mars

Sojourner takes its Alpha Proton X-ray Spectrometer measurement of the Yogi Rock.

The landing site of each Mars mission can be seen on this rotating globe.

Active missions at Mars

Year
2012	5
2011	4
2010	5
2009	5
2008	6
2007	5
2006	6

The exploration of Mars has taken place over hundreds of years, beginning in earnest with the invention and development of the telescope in the 1600s. Increasingly detailed views of the planet from Earth inspired speculation about its environment and possible life – even intelligent civilizations – which might be found there. Probes sent from Earth beginning in the late 20th century have yielded a dramatic increase in knowledge about the Martian system, focused primarily on understanding its geology and possible biology. (See also: Mars landing.)

Mars exploration has been an important part of the space exploration programs of the Soviet Union, the United States, Russia, and Europe, with Japan, China, Finland, and India also attempting to do so. Dozens of robotic spacecraft, including orbiters, landers, and rovers, have been launched toward Mars since the 1960s. These missions were aimed at gathering data about current conditions and answering questions about the history of Mars as well as a preparation for a possible human mission to Mars. The questions raised by the scientific community are expected to not only give a better appreciation of the red planet but also yield further insight into the past, and possible future, of Earth.

Due to the complexity involved in engineering an interplanetary journey, the exploration of Mars has experienced a high failure rate, especially in early attempts, with roughly two-thirds of all spacecraft destined for Mars failing before completing their missions, with some failing even before observations could begin. However, missions have also met with unexpected levels of success, such as the twin Mars Exploration Rovers operating for years beyond their original mission specifications.

As of 6 August 2012, there are two rovers on the surface of Mars beaming signals back to Earth (Curiosity and Opportunity), and three orbiters currently surveying the planet (Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter). So far, no sample return missions have been attempted for Mars, and one attempted return mission for Mars' moon Phobos (Fobos-Grunt) has failed.

Martian system

Main articles: Mars, Atmosphere of Mars, and Moons of Mars

Viking Lander 2 site - May 1979

Viking Lander 1 site - February 1978

Mars has long been the subject of human fascination. Early telescopic observations revealed color changes on the surface which were originally attributed to seasonal vegetation as well as apparent linear features which were ascribed to intelligent design. These early and erroneous interpretations led to widespread public interest in Mars. Further telescopic observations found Mars' two moons, Phobos and Deimos, the polar ice caps, and the feature now known as Olympus Mons, the solar system's tallest mountain. These discoveries piqued further interest in the study and exploration of the red planet. Mars is a rocky planet, like Earth, that formed around the same time, yet with only half the diameter of Earth, and a far thinner atmosphere, it has a cold and desert-like surface. It is notable, however, that although the planet has only one quarter of the surface area of the Earth, it has about the same land area, since only one quarter of the surface area of the Earth is land.

The amount of data returned by probes has increased dramatically as technology has improved. For example, Mariner 4 returned 21 images in the 1960s, but Mariner 9 returned 7329 images in the 1970s.

Launch windows

In order to understand the history of the robotic exploration of Mars it is important to note that minimum-energy launch windows occur at intervals of approximately 2.135 years, i.e. 780 days (the planet's synodic period with respect to Earth).

Every 26 Earth months a lower energy Earth to Mars transfer opportunity opens. In addition, the lowest available transfer energy varies on a roughly 16 year cycle, with a minimum in the 1969 and 1971 launch windows, rising to a peak in the late 70s, and hitting another low in 1986 and 1988.

In addition to these minimum-energy trajectories, which occur when the planets are aligned so that the Earth to Mars transfer trajectory goes halfway around the Sun, an alternate trajectory which has been proposed goes first inward toward Venus orbit, and then outward, resulting in a longer trajectory which goes about 360 degrees around the Sun.

Overview

The following entails a brief overview of Mars exploration, oriented towards orbiters and flybys; see also Mars landing.

Early Soviet missions

Main articles: Mars 1M, Mars 1, and Mars probe program

Mars 1M spacecraft

1960s

The Mars 1M program (sometimes dubbed Marsnik in Western media) was the first Soviet unmanned spacecraft interplanetary exploration program, which consisted of two flyby probes launched towards Mars in October 1960, Mars 1960A and Mars 1960B (also known as Korabl 4 and Korabl 5 respectively). After launch, the third stage pumps on both launchers were unable to develop enough thrust to commence ignition, so Earth parking orbit was not achieved. The spacecraft reached an altitude of 120 km before reentry.

Mars 1962A was a Mars fly-by mission, launched on October 24, 1962 and Mars 1962B a lander mission, launched in late December of the same year. Both failed from either breaking up as they were going into Earth orbit or having the upper stage explode in orbit during the burn to put the spacecraft into trans-Mars trajectory.

Mars 1 (1962 Beta Nu 1), an automatic interplanetary spacecraft launched to Mars on November 1, 1962, was the first probe of the Soviet Mars probe program. Mars 1 was intended to fly by the planet at a distance of about 11,000 km and take images of the surface as well as send back data on cosmic radiation, micrometeoroid impacts and Mars' magnetic field, radiation environment, atmospheric structure, and possible organic compounds. Sixty-one radio transmissions were held, initially at two day intervals and later at 5 day intervals, from which a large amount of interplanetary data was collected. On 21 March 1963, when the spacecraft was at a distance of 106,760,000 km from Earth, on its way to Mars, communications ceased due to failure of its antenna orientation system.

In 1964, both Soviet probe launches, of Zond 1964A on June 4, and Zond 2 on November 30, (part of the Zond program), resulted in failures. Zond 1964A had a failure at launch, while communication was lost with Zond 2 en route to Mars after a mid-course maneuver, in early May 1965.

In 1969, the Soviet Union prepared a 5-ton orbiter called M-69. Two copies of the probe were lost in launch related complications caused by problems with the newly developed Proton rockets.

1970s

The USSR intended to have the first artificial satellite of Mars beating the planned American Mariner 8 and Mariner 9 martian orbiters. But on May 5, 1971 Cosmos 419 (Mars 1971C), a heavy probe of the Soviet Mars program M-71, failed on launch. This spacecraft was designed as an orbiter only, while the second and third probes of project M-71, Mars 2 and Mars 3, were multi-aimed combinations of orbiter and lander.

In 1971, shortly after the Cosmos 419 probe was lost in the fourth stage of the launch due to issues concerning the failure in the separation of Cosmos' payload from the launch vehicle, the Soviet Union successfully sent probes Mars 2 and Mars 3, as part of the Mars probe program. The Mars 2 and 3 orbiters each carried a lander, and they became first known probes to touch down on Mars. They both had technical problems that prevented returning useful scientific data.

The Mars 2 and 3 orbiters sent back a relatively large volume of data covering the period from December 1971 to March 1972, although transmissions continued through to August. By 22 August 1972, after sending back data and a total of 60 pictures, Mars 2 and 3 concluded their missions. The images and data enabled creation of surface relief maps, and gave information on the Martian gravity and magnetic fields.

In 1973, the Soviet Union sent four more probes to Mars: the Mars 4 and Mars 5 orbiters and the Mars 6 and Mars 7 fly-by/lander combinations. All missions except Mars 7 sent back data, with Mars 5 being most successful. Mars 5 transmitted 60 images before a loss of pressurization in the transmitter housing ended the mission. Mars 6 lander transmitted data during descent, but failed upon impact. Mars 4 flew by the planet at a range of 2200 km returning one swath of pictures and radio occultation data, which constituted the first detection of the nightside ionosphere on Mars. Mars 7 probe separated prematurely from the carrying vehicle due to a problem in the operation of one of the onboard systems (altitude control or retro-rockets) and missed the planet by 1300 km.

Mariner program

Main articles: Mariner program, Mariner 4, Mariner 6 and 7, and Mariner 9

The first close-up images taken of Mars in 1965 from Mariner 4 show an area about 330 km across by 1200 km from limb to bottom of frame.

Mariner Crater, as seen by Mariner 4. The location is Phaethontis quadrangle.

In 1964, NASA's Jet Propulsion Laboratory made two attempts at reaching Mars. Mariner 3 and Mariner 4 were identical spacecraft designed to carry out the first flybys of Mars. Mariner 3 was launched on November 5, 1964, but the shroud encasing the spacecraft atop its rocket failed to open properly, dooming the mission. Three weeks later, on November 28, 1964, Mariner 4 was launched successfully on a 7½-month voyage to the red planet.

Mariner 4 flew past Mars on July 14, 1965, providing the first close-up photographs of another planet. The pictures, gradually played back to Earth from a small tape recorder on the probe, showed impact craters. It provided radically more accurate data about the planet; a surface atmospheric pressure of about 1% of Earth's and daytime temperatures of -100 degrees Celsius (-148 degrees Fahrenheit) were estimated. No magnetic field or Martian radiation belts were detected. The new data meant redesigns for then planned Martian landers, and showed life would have a more difficult time surviving there than previously anticipated.

NASA continued the Mariner program with another pair of Mars flyby probes, Mariner 6 and 7. They were sent at the next launch window, and reached the planet in 1969. During the following launch window the Mariner program again suffered the loss of one of a pair of probes. Mariner 9 successfully entered orbit about Mars, the first spacecraft ever to do so, after the launch time failure of its sister ship, Mariner 8. When Mariner 9 reached Mars, it and two Soviet orbiters (Mars 2 and Mars 3, see Mars probe program below) found that a planet-wide dust storm was in progress. The mission controllers used the time spent waiting for the storm to clear to have the probe rendezvous with, and photograph, Phobos. When the storm cleared sufficiently for Mars' surface to be photographed by Mariner 9, the pictures returned represented a substantial advance over previous missions. These pictures were the first to offer more detailed evidence that liquid water might at one time have flowed on the planetary surface. They also finally discerned the true nature of many Martian albedo features. For example, Nix Olympica was one of only a few features that could be seen during the planetary duststorm, revealing it to be the highest mountain (volcano, to be exact) on any planet in the entire Solar System, and leading to its reclassification as Olympus Mons.

Viking program

Main articles: Viking program, Viking 1, and Viking 2

The Viking program launched Viking 1 and 2 spacecraft to Mars in 1975; The program consisted of two orbiters and two landers. 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. The primary scientific objectives of the lander mission were to search for biosignatures and observe meteorology, seismology and magnetic properties of Mars.

• 
  Streamlined islands in Lunae Palus quadrangle.
• 
  Tear-drop shaped islands at Oxia Palus quadrangle.
• 
  Scour patterns located in Lunae Palus quadrangle.
• 
  Lunae Palus quadrangle was eroded by large amounts of liquid water.

Mars Pathfinder

Main articles: Mars Pathfinder and Mars landing

Mars Pathfinder was a U.S. spacecraft that landed a base station with a roving probe on Mars in July 4, 1997. It consisted of a lander and a small 10.6 kilograms (23 lb) wheeled robotic rover named Sojourner, which was the first rover to operate on the surface of Mars. In addition to scientific objectives, the Mars Pathfinder mission was also a "proof-of-concept" for various technologies, such as airbag landing system and automated obstacle avoidance, both later exploited by the Mars Exploration Rovers.

Mars Global Surveyor

Main article: Mars Global Surveyor

This image from Mars Global Surveyor spans a region about 1500 meters across. Gullies, similar to those formed on Earth, are visible from Newton Basin in Sirenum Terra (NASA).

This color-coded elevation map was produced from data collected by Mars Global Surveyor. It shows an area around Northern Kasei Valles, showing relationships among Kasei Valles, Bahram Vallis, Vedra Vallis, Maumee Vallis, and Maja Valles. Map location is in Lunae Palus quadrangle and includes parts of Lunae Planum and Chryse Planitia.

After the 1992 failure of NASA's Mars Observer orbiter, NASA retooled and launched Mars Global Surveyor (MGS). This mission was the first successful United States mission, and the first fully successful mission overall, to the red planet in two decades when it launched November 7, 1996, and entered orbit on September 12, 1997. After a year and a half trimming its orbit from a looping ellipse to a circular track around the planet, the spacecraft began its primary mapping mission in March 1999. It observed the planet from a low-altitude, nearly polar orbit over the course of one complete Martian year, the equivalent of nearly two Earth years. Mars Global Surveyor completed its primary mission on January 31, 2001, and completed several extended mission phases.

The mission studied the entire Martian surface, atmosphere, and interior, and returned more data about the red planet than all previous Mars missions combined. The data has been archived and remains available publicly.

Among key scientific findings, Global Surveyor took pictures of gullies and debris flow features that suggest there may be current sources of liquid water, similar to an aquifer, at or near the surface of the planet. Similar channels on Earth are formed by flowing water, but on Mars the temperature is normally too cold and the atmosphere too thin to sustain liquid water. Nevertheless, many scientists hypothesize that liquid groundwater can sometimes surface on Mars, erode gullies and channels, and pool at the bottom before freezing and evaporating.

Magnetometer readings showed that the planet's magnetic field is not globally generated in the planet's core, but is localized in particular areas of the crust. New temperature data and closeup images of the Martian moon Phobos showed that its surface is composed of powdery material at least 1 metre (3 feet) thick, caused by millions of years of meteoroid impacts. Data from the spacecraft's laser altimeter gave scientists their first 3-D views of Mars' north polar ice cap.

On November 5, 2006 MGS lost contact with Earth. NASA ended efforts to restore communication on January 28, 2007.

Odyssey & Express

Main articles: 2001 Mars Odyssey and Mars Express

In 2001 the run of bad luck ended when NASA's Mars Odyssey orbiter arrived. Its mission is to use spectrometers and imagers to hunt for evidence of past or present water and volcanic activity on Mars. In 2002, it was announced that the probe's gamma ray spectrometer and neutron spectrometer had detected large amounts of hydrogen, indicating that there are vast deposits of water ice in the upper three meters of Mars' soil within 60° latitude of the south pole.

On June 2, 2003, the European Space Agency's Mars Express set off from Baikonur Cosmodrome to Mars. The Mars Express craft consists of the Mars Express Orbiter and the lander Beagle 2. Although the landing probe was not designed to move, it carried a digging device and the smallest mass spectrometer created to date, as well as a range of other devices, on a robotic arm in order to accurately analyze soil beneath the dusty surface.

The orbiter entered Mars orbit on December 25, 2003, and Beagle 2 entered Mars' atmosphere the same day. However, attempts to contact the lander failed. Communications attempts continued throughout January, but Beagle 2 was declared lost in mid-February, and a joint inquiry was launched by the UK and ESA. The Mars Express Orbiter confirmed the presence of water ice and carbon dioxide ice at the planet's south pole, while NASA had previously confirmed their presence at the north pole of Mars.

MER & Phoenix

Main articles: Mars Exploration Rover, Opportunity rover, Spirit rover, and Phoenix lander

Arctic surface as seen by Phoenix

See Mars landing for more on the landers.

Mars Reconnaissance Orbiter

Main article: Mars Reconnaissance Orbiter

Mars Reconnaissance Orbiter is a multipurpose spacecraft designed to conduct reconnaissance and exploration of Mars from orbit. The $720 million USD spacecraft was built by Lockheed Martin under the supervision of the Jet Propulsion Laboratory, launched August 12, 2005, and attained Martian orbit on March 10, 2006.

The MRO contains a host of scientific instruments such as the HiRISE camera, CTX camera, CRISM, and SHARAD. The HiRISE camera is used to analyze Martian landforms, whereas CRISM and SHARAD can detect water, ice, and minerals on and below the surface. Additionally, MRO is paving the way for upcoming generations of spacecraft through daily monitoring of Martian weather and surface conditions, searching for future landing sites, and testing a new telecommunications system that enable it to send and receive information at an unprecedented bitrate, compared to previous Mars spacecraft. Data transfer to and from the spacecraft occurs faster than all previous interplanetary missions combined and allows it to serve as an important relay satellite for other missions.

Rosetta and Dawn swingbys

Main articles: Rosetta (spacecraft) and Dawn Mission

The ESA Rosetta space probe mission to the comet 67P/Churyumov-Gerasimenko flew within 250 km of Mars on February 25, 2007 in a gravitational slingshot designed to slow and redirect the spacecraft. The NASA Dawn spacecraft also used the gravity of Mars to change direction and velocity, and did a little science in conjunction with the many probes already there. Dawn passed the red planet in February 2009.

Mars Science Laboratory and Fobos-Grunt

Main articles: Mars Science Laboratory and Fobos-Grunt

In late 2011, there were two separate launches: NASA's Mars Science Laboratory (MSL) and Roscosmos' Fobos-Grunt lander with sample return. The MSL, with its Martian rover named "Curiosity", was launched on November 26, 2011 and contains instruments designed to look for past or present conditions relevant to habitability. The MSL has landed on Mars on Aeolis Palus in Gale Crater, near Aeolis Mons (formerly, "Mount Sharp"), on August 6, 2012 at 05:14:39 UTC.

The Fobos-Grunt mission, on the other hand, suffered a complete control and communications failure during launch and was left stranded in low Earth orbit, later falling back to Earth.

Manned mission proposals

Main article: Manned mission to Mars

Many people have long advocated a manned mission to Mars as the next logical step for a manned space program after lunar exploration. Aside from the prestige such a mission would bring, advocates argue that humans would easily be able to outperform robotic explorers, justifying the expense. Aerospace engineer Bob Zubrin is one of the proponents of such missions. Some critics contend unmanned robots can perform better than humans at a fraction of the expense. If life exists on Mars, a manned mission could contaminate it by introducing earthly microbes, so robotic exploration would be preferable. A list of hypothetical or proposed manned Mars missions is located at manned mission to Mars. See also, colonization of Mars.

Probing difficulties

Mars Climate Orbiter returned this one image of Mars in 1999 before crashing into it

Main articles: Phobos 1, Mars Observer, Mars 96, Nozomi, Mars Climate Orbiter, Mars Polar Lander, Deep Space 2, and Beagle 2

The high failure rate of missions launched from Earth attempting to explore Mars was informally called the "Mars Curse" or "Martian Curse". The phrase "Galactic Ghoul" or "Great Galactic Ghoul", referring to a fictitious space monster which subsists on a diet of Mars probes, was coined in 1997 by Time Magazine journalist Donald Neff, and is sometimes facetiously used to "explain" the recurring difficulties.

Of 38 launches from Earth in an attempt to reach the planet, only 19 have succeeded, and As of November 2011, the success rate is 50%. Twelve of the missions included attempts to land on the surface, but only seven transmitted data after landing. The majority of the failed missions occurred in the early years of space exploration and were part of the Soviet and later Russian Mars probe program that suffered several technical difficulties. Modern missions have an improved success rate; however, the challenge, complexity and length of the missions make it likely that failures will occur.

The U.S. NASA Mars exploration program has had a somewhat better record of success in Mars exploration, achieving success in 13 out of 20 missions launched (a 65% success rate), and succeeding in six out of seven (an 86% success rate) lander missions.

After Viking concluded in the early 1980s, a difficult period of failures began. Two Soviet probes were sent to Mars in 1988 as part of the Phobos program. Phobos 1 operated nominally until an expected communications session on 2 September 1988 failed to occur. The problem was traced to a software error, which deactivated attitude thrusters causing the spacecrafts' solar arrays to no longer point at the Sun, depleting Phobos 1 batteries. Phobos 2 operated nominally throughout its cruise and Mars orbital insertion phases on January 29, 1989, gathering data on the Sun, interplanetary medium, Mars, and Phobos. Shortly before the final phase of the mission, during which the spacecraft was to approach within 50 m of Phobos' surface and release two landers, one a mobile 'hopper', the other a stationary platform, contact with Phobos 2 was lost. The mission ended when the spacecraft signal failed to be successfully reacquired on March 27, 1989. The cause of the failure was determined to be a malfunction of the on-board computer.

Just a few years later Mars Observer failed as it approached Mars. Mars 96, an orbiter launched on November 16, 1996 by Russia failed, when the planned second burn of the Block D-2 fourth stage did not occur.

Following the success of Global Surveyor and Pathfinder, another spate of failures occurred in 1998 and 1999, with the Japanese Nozomi orbiter and NASA's Mars Climate Orbiter, Mars Polar Lander, and Deep Space 2 penetrators all suffering various fatal errors. Mars Climate Orbiter is infamous for Lockheed Martin engineers mixing up the usage of English units with metric units, causing the orbiter to burn up while entering Mars' atmosphere.

Timeline of Mars exploration

Source: international Mars mission log

Totals

File:Mars-exploration-family-portrait.jpg

The Mars Exploration Family Portrait shows a summary of most spacecraft sent to Mars.

Mission type	Success rate	Total attempts	Success	Partial success	Launch failure	Failed en route	Failed to orbit/land
Flyby	45%	11	5		4	2
Orbiter	50%	22	9	2	5	3	3
Lander	30%	10	3			3	4
Rover	80%	5	3	1			1
Sample return	0%	1				1 (Phobos)
Total	47%	49	20	3	9	9	8

Timeline

Mission (1960–1969)	Launch	Arrival at Mars	Termination	Elements	Result
Mars 1M No.1	10 October 1960		10 October 1960	Flyby	Launch failure
Mars 1M No.2	14 October 1960		14 October 1960	Flyby	Launch failure
Mars 2MV-4 No.1	24 October 1962		24 October 1962	Flyby	Broke up shortly after launch
Mars 1	1 November 1962		21 March 1963	Flyby	Some data collected, but lost contact before reaching Mars, flyby at approx. 193,000 km
Mars 2MV-3 No.1	4 November 1962		19 January 1963	Lander	Failed to leave Earth's orbit
Mariner 3	5 November 1964		5 November 1964	Flyby	Failure during launch ruined trajectory
Mariner 4	28 November 1964	14 July 1965	21 December 1967	Flyby	Success (21 images returned)
Zond 2	30 November 1964		May 1965	Flyby	Communication lost three months before reaching Mars
Mariner 6	25 February 1969	31 July 1969	August 1969	Flyby	Success
Mariner 7	27 March 1969	5 August 1969	August 1969	Flyby	Success
Mars 2M No.521	27 March 1969		27 March 1969	Orbiter	Launch failure
Mars 2M No.522	2 April 1969		2 April 1969	Orbiter	Launch failure
Mission (1970–1989)	Launch	Arrival at Mars	Termination	Elements	Result
Mariner 8	8 May 1971		8 May 1971	Orbiter	Launch failure
Kosmos 419	10 May 1971		12 May 1971	Orbiter	Launch failure
Mariner 9	30 May 1971	13 November 1971	27 October 1972	Orbiter	Success (first successful orbit)
Mars 2	19 May 1971	27 November 1971	22 August 1972	Orbiter	Success
			27 November 1971	Lander, rover	Crashed on surface of Mars
Mars 3	28 May 1971	2 December 1971	22 August 1972	Orbiter	Success
			2 December 1971	Lander, rover	Partial success. First successful landing; landed softly but ceased transmission within 15 seconds
Mars 4	21 July 1973	10 February 1974	10 February 1974	Orbiter	Could not enter orbit, made a close flyby
Mars 5	25 July 1973	2 February 1974	21 February 1974	Orbiter	Partial success. Entered orbit and returned data, but failed within 9 days
Mars 6	5 August 1973	12 March 1974	12 March 1974	Lander	Partial success. Data returned during descent but not after landing on Mars
Mars 7	9 August 1973	9 March 1974	9 March 1974	Lander	Landing probe separated prematurely; entered heliocentric orbit
Viking 1	20 August 1975	20 July 1976	17 August 1980	Orbiter	Success
			13 November 1982	Lander	Success
Viking 2	9 September 1975	3 September 1976	25 July 1978	Orbiter	Success
			11 April 1980	Lander	Success
Phobos 1	7 July 1988		2 September 1988	Orbiter	Contact lost while en route to Mars
				Lander	Not deployed
Phobos 2	12 July 1988	29 January 1989	27 March 1989	Orbiter	Partial success: entered orbit and returned some data. Contact lost just before deployment of landers
				Landers	Not deployed
Mission (1990–1999)	Launch	Arrival at Mars	Termination	Elements	Result
Mars Observer	25 September 1992	24 August 1993	21 August 1993	Orbiter	Lost contact just before arrival
Mars Global Surveyor	7 November 1996	11 September 1997	5 November 2006	Orbiter	Success
Mars 96	16 November 1996		17 November 1996	Orbiter, lander, penetrator	Launch failure
Mars Pathfinder	4 December 1996	4 July 1997	27 September 1997	Lander, rover	Success
Nozomi (Planet-B)	3 July 1998		9 December 2003	Orbiter	Complications while en route; Never entered orbit
Mars Climate Orbiter	11 December 1998	23 September 1999	23 September 1999	Orbiter	Crashed on surface due to metric-imperial mix-up
Mars Polar Lander	3 January 1999	3 December 1999	3 December 1999	Lander	Crash-landed on surface due to improper hardware testing
Deep Space 2 (DS2)				Hard landers
Mission (2000–2009)	Launch	Arrival at Mars	Termination	Elements	Result
2001 Mars Odyssey	7 April 2001	24 October 2001	Currently operational	Orbiter	Success
European Space Agency Mars Express	2 June 2003	25 December 2003	Currently operational	Orbiter	Success
Beagle 2			6 February 2004	Lander, rover	Landing failure; fate unknown.
MER-A Spirit	10 June 2003	4 January 2004	22 March 2011	Rover	Success
MER-B Opportunity	7 July 2003	25 January 2004	Currently operational	Rover	Success
European Space Agency Rosetta	2 March 2004	25 February 2007	Currently operational	Gravity assist enroute to comet 67P/Churyumov-Gerasimenko	Success
Mars Reconnaissance Orbiter	12 August 2005	10 March 2006	Currently operational	Orbiter	Success
Phoenix	4 August 2007	25 May 2008	10 November 2008	Lander	Success
Dawn	27 September 2007	17 February 2009	Currently operational	Gravity assist to Vesta	Success
Mission (2010–2019)	Launch	Arrival at Mars	Termination	Elements	Result
Fobos-Grunt	8 November 2011		8 November 2011	Phobos lander, sample return	Failed to leave Earth orbit. Rescue attempts unsuccessful
China National Space Administration Yinghuo-1			8 November 2011	Orbiter
MSL Curiosity	26 November 2011	6 August 2012	Currently operational	Rover	Success

Future missions

Name	Estimated launch	Elements	Notes
Indian Mars probe	20 November 2013	Orbiter	Research on Mars Atmosphere
MAVEN	2013	Orbiter	Will study Mars' upper atmosphere
European Space Agency ExoMars	2016	Orbiter, lander	Trace Gas Orbiter to deliver a lander.
	2018	Lander, rover	Russian lander to deploy ExoMars rover
MetNet precursor	2014 or later	Impact lander	Precursor for Multi-lander network.

Under study

Name	Estimated launch	Elements	Notes
InSight	2016	Lander	Competing with two other concepts in the Discovery program
Mars Geyser Hopper	2016	Lander	Will have the ability to fly or "hop" at least twice from its landed location to reposition itself close to a CO2 geyser site.
MetNet	after precursor	Multi-lander network	Simultaneous meteorological measurements at multiple locations.
Red Dragon	2018	Lander	Falcon Heavy rocket with a Dragon capsule; would look for biosignatures.
European Space Agency Network	2022	Carrier, 3 small impact landers	Meteorological network concept
European Space Agency MMSR	2022	Lander and ascent stage	Mars Moon Sample Return Mission concept
Mars One	2022	Manned mission	The first supply vehicle is planned for launch in 2016
MELOS-1	2020s	Orbiter, lander	Would study geology and atmosphere.
Mars-Grunt	2020s	Orbiter, lander, ascent stage	Single launch Mars sample return
BOLD	-	6 penetration landers	The Biological Oxidant and Life Detection would perform astrobiology tests on sub-surface soil

Undeveloped concepts

• Mars 4NM and Mars 5NM - projects intended by the Soviet Union for heavy Marsokhod (in 1973 according to initial plan of 1970) and Mars sample return (planned for 1975) missions by launching on N1 rocket that has never flown successfully.
• Voyager - USA, 1970s - Two orbiters and two landers, launched by a single Saturn V rocket.
• Mars Aerostat - Russian/French balloon mission, originally planned for the 1992 launch window, postponed to 1994 and then to 1996 before being cancelled.
• Mars Environmental Survey - set of 16 landers planned for 1999–2009
• Mars-98 - Russian mission including an orbiter, lander, and rover, planned for 1998 launch opportunity
• Mars Surveyor 2001 Lander - October 2001 - Mars lander (refurbished, became Phoenix lander)
• Beagle 3 - 2009 British lander mission meant to search for life, past or present.
• NetLander- 2007 or 2009 - Mars netlanders
• Mars Telecommunications Orbiter - September 2009 - Mars orbiter for telecommunications
• Mars Astrobiology Explorer-Cacher - 2018 rover
• Kitty Hawk - Mars airplane micromission, proposed for December 17, 2003, the centennial of the Wright brother's first flight. Its funding was eventually given to the 2003 Mars Network project.
• Tumbleweed rover.

See also

Mars

• History of Mars observation
• Life on Mars
• List of artificial objects on Mars
• Mars to Stay
• Mars Scout Program

General

• Atmospheric reentry
• Jet Propulsion Laboratory Science Division
• Observations and explorations of Venus
• Space colonization
• Space exploration
• Space weather
• Timeline of Solar System exploration

Further reading

• Mars - A Warmer, Wetter Planet by Jeffrey S. Kargel (published July 2004; ISBN 978-1-85233-568-7)
• The Compact NASA Atlas of the Solar System by Ronald Greeley and Raymond Batson (published January 2002; ISBN 0-521-80633-X)
• Mars: The NASA Mission Reports / edited by Robert Godwin (2000) ISBN 1-896522-62-9

External links

• Mars Program by the American JPL
• Mars Rovers' newsroom
• Next on Mars (Bruce Moomaw, Space Daily, 9 March 2005): An extensive overview of NASA's Mars exploration plans
• Catalog of Soviet Mars images Collection of Russian Mars probes' images.
• Mars balloon
• NASA History Series Publications (many of which are on-line)
• Simplified study of orbits to land on Mars and return to Earth High School level.
• NASA PROGRAM & MISSIONS
• Mapping Mars, now and in history (2009)
• Mars Exploration art (NASA)
• Mars by Rosetta (hosted by The Planetary Society)