Historical

Mission, Country, Launch Date, Purpose, Results

• [Unnamed], USSR, 10/10/60, Mars flyby, did not reach Earth orbit
• [Unnamed], USSR, 10/14/60, Mars flyby, did not reach Earth orbit
• [Unnamed], USSR, 10/24/62, Mars flyby, achieved Earth orbit only
• Mars 1, USSR, 11/1/62, Mars flyby, radio failed at 106 million km (65.9 million miles)
• [Unnamed], USSR, 11/4/62, Mars flyby, achieved Earth orbit only
• Mariner 3, U.S., 11/5/64, Mars flyby, shroud failed to jettison
• Mariner 4, U.S. 11/28/64, first successful Mars flyby 7/14/65, returned 21 photos
• Zond 2, USSR, 11/30/64, Mars flyby, passed Mars but radio failed, returned no planetary data
• Mariner 6, U.S., 2/24/69, Mars flyby 7/31/69, returned 75 photos
• Mariner 7, U.S., 3/27/69, Mars flyby 8/5/69, returned 126 photos
• Mariner 8, U.S., 5/8/71, Mars orbiter, failed during launch
• Kosmos 419, USSR, 5/10/71, Mars lander, achieved Earth orbit only
• Mars 2, USSR, 5/19/71, Mars orbiter/lander arrived 11/27/71, no useful data, lander burned up due to steep entry
• Mars 3, USSR, 5/28/71, Mars orbiter/lander, arrived 12/3/71, lander operated on surface for 20 seconds before failing
• Mariner 9, U.S., 5/30/71, Mars orbiter, in orbit 11/13/71 to 10/27/72, returned 7,329 photos
• Mars 4, USSR, 7/21/73, failed Mars orbiter, flew past Mars 2/10/74
• Mars 5, USSR, 7/25/73, Mars orbiter, arrived 2/12/74, lasted a few days
• Mars 6, USSR, 8/5/73, Mars flyby module and lander, arrived 3/12/74, lander failed due to fast impact
• Mars 7, USSR, 8/9/73, Mars flyby module and lander, arrived 3/9/74, lander missed the planet
• Viking 1, U.S., 8/20/75, Mars orbiter/lander, orbit 6/19/76-1980, lander 7/20/76-1982
• Viking 2, U.S., 9/9/75, Mars orbiter/lander, orbit 8/7/76-1987, lander 9/3/76-1980; combined, the Viking orbiters and landers returned 50,000+ photos
• Phobos 1, USSR, 7/7/88, Mars/Phobos orbiter/lander, lost 8/88 en route to Mars
• Phobos 2, USSR, 7/12/88, Mars/Phobos orbiter/lander, lost 3/89 near Phobos
• Mars Observer, U.S., 9/25/92, lost just before Mars arrival 8/21/93
• Mars Global Surveyor, U.S., 11/7/96, Mars orbiter, arrived 9/12/97, high-detail mapping through 1/00, now conducting second extended mission through fall 2004
• Mars 96, Russia, 11/16/96, orbiter and landers, launch vehicle failed
• Mars Pathfinder, U.S., 12/4/96, Mars lander and rover, landed 7/4/97, last transmission 9/27/97
• Nozomi, Japan, 7/4/98, Mars orbiter, currently in orbit around the Sun; Mars arrival delayed to 12/13/03 then fails
• Mars Climate Orbiter, U.S., 12/11/98, lost upon arrival 9/23/99
• Mars Polar Lander/Deep Space 2, U.S., 1/3/99, lander and soil probes, lost on arrival 12/3/99
• Mars Odyssey, U.S., 3/7/01, Mars orbiter, arrived 10/24/01, currently conducting prime mission studying global composition, ground ice, thermal imaging
• Mars Express/Beagle 2, European Space Agency, 6/2/03, Mars orbiter/lander, due to enter orbit 12/25/03, landing 12/25/03 (evening of 12/24/03 in U.S. time zones)

Recent and Future NASA Mars Missions

Building on scientific discoveries and lessons learned from past and ongoing missions, NASA's Mars Exploration Program will establish a sustained observational presence both around and on the surface of Mars in coming years. This will include orbiters that view the planet from above and act as telecommunications relays; surface-based mobile laboratories; robots that probe below the planet's surface; and, ultimately, missions that return soil and rock samples to Earth. With interna-tional cooperation, the long-term program will be guided by compelling questions that scientists are interested in answering about Mars, developing technologies to make missions possible within available resources. The program's strategy is to seek to uncover profound new insights into Mars' past environments, the history of its rocks and interior, the many roles and abundances of water and, quite possibly, evidence of past and present life.

The following are the most recently completed, ongoing and near-term future Mars missions of exploration in the NASA program:

• Mars Pathfinder (December 1996 - March 1998): The first completed mission in NASA's Discovery Program of low-cost, rapidly developed planetary missions with highly focused scientific goals, Mars Pathfinder far exceeded its expectations and outlived its primary design life. This lan-der, which released its Sojourner rover at the martian surface, returned 2.3 billion bits of informa-tion, including more than 17,000 images and more than 15 chemical analyses of rocks and soil and extensive data on winds and other types of weather. Investigations carried out by instruments on both the lander and the rover suggest that, in its past, Mars was warm and wet, with liquid water on its surface and a thicker atmosphere. The lander and rover functioned far beyond their planned lifetimes (30 days for the lander and 7 days for the rover), but eventually, after about three months on the martian surface, depletion of the lander's battery and a drop in the lander's operating tem-perature are thought to have ended the mission.
• Mars Global Surveyor (November 1996 - present): During its primary mapping mission from March 1999 through January 2001, NASA's Mars Global Surveyor collected more information than any other previous Mars mission. Today the orbiter continues to gather data in a second extended mission. As of May 1, 2003, it has completed more than 20,000 orbits of Mars and returned more than 137,000 images, 671 million laser-altimeter shots and 151 million spectrometer measure-ments. Some of the mission's most significant findings include: evidence of possibly recent liquid water at the martian surface; evidence for layering of rocks that points to widespread ponds or lakes in the planet's early history; topographic evidence that most of the southern hemisphere is higher in elevation than most of the northern hemisphere, so that any downhill flow of water and sediments would have tended to be northward; identification of gray hematite, a mineral suggesting a wet environment when it was formed; and extensive evidence for the role of dust in reshaping the recent martian environment. Global Surveyor provided valuable details for evaluating the risks and attractions of potential landing sites for the Mars Exploration Rover missions, and it will serve as a communications relay for the rovers as they descend to land on Mars and afterwards.
• Mars Climate Orbiter and Mars Polar Lander (1998-99): These spacecraft were both lost upon Mars arrival.
• Mars Odyssey (April 2001 - present): This orbiter's prime mapping mission began in March 2002. Its suite of gamma-ray spectrometer instruments has provided strong evidence for large quantities of frozen water mixed into the top layer of soil in the 20 percent of the planet near its north and south poles. By one estimate -- likely an underestimate -- the amount of water ice near the surface, if melted, would be enough water to fill Lake Michigan twice. Odyssey's infrared camera system has also provided detailed maps of minerals in rocks and soils. A layer of olivine-rich rock in one canyon near Mars' equator suggests that site has been dry for a long time, since olivine is easily weathered by liquid water. Nighttime infrared imaging by Odyssey's camera sys-tem provides information about how quickly or slowly surface features cool off after sunset, which gives an indication of where the surface is rocky and where it is dusty. Odyssey's observations have helped evaluate potential landing sites for the Mars Exploration Rovers. When the rovers reach Mars, radio relay via Odyssey will be one way they will return data to Earth.
• Mars Reconnaissance Orbiter (2005): This mission is being developed to provide detailed information about thousands of sites on Mars, connecting the big-picture perspective of an orbiter with a level of local detail that has previously come only from landing a spacecraft on the surface. The spacecraft's telescopic camera will reveal martian landscapes in resolution fine enough to show rocks the size of a desk. Maps of surface minerals will be produced in unprecedented detail for thousands of potential future landing sites. Scientists will search in particular for types of miner-als that form in wet environments. A radar instrument on the orbiter will probe hundreds of meters (or yards) below Mars' surface for layers of frozen or melted water, and other types of geologic lay-ers. Another instrument will document atmospheric processes changing with Mars' seasons, and study how water vapor enters, moves within and leaves the atmosphere.
• Phoenix Mars Scout (2007): This mission will send a spacecraft to land in an ice-rich region of northern Mars, scoop up soil to analyze at the landing site, and radio home evidence about the his-tory of martian water and the possibility of past or current life. NASA chose Phoenix in August 2003 to be the first flight in the Mars Scout program of competitively selected missions. Phoenix will land in May 2008 on arctic ground where Mars Odyssey has found abundant ice near the sur-face. A stereo color camera and a weather station will study the surrounding environment while other instruments check excavated soil samples for water, organic chemicals and conditions that could indicate whether the site was ever hospitable to life. Microscopes will reveal features as small as 1/1,000th the width of a human hair. The mission will use many components of a space-craft originally built for a 2001 Mars lander mission, which was kept in storage after that mission was cancelled. NASA plans to select a second Mars Scout from a future round of proposals to fly in 2011.
• Mars Science Laboratory (2009): Following the high-resolution study of the planet by the Mars Reconnaissance Orbiter in search for the highest-priority sites on Mars, the program calls for a precision lander to one of those sites in search for habitable environments and the basic building blocks of life. Baselined as being nuclear-powered, the mission will also take advantage of advances in entry, descent and landing technologies to enable it to access about three-fourths of Mars. It will have the capability to move on the surface for a full martian year or longer, and across distances an order of magnitude larger than the Mars Exploration Rovers.
• Mars Telecommunications Orbiter (2009): This mission will be the first interplanetary space-craft whose primary mission is to provide communications services to other missions. It will fly in a higher orbit than any previous Mars orbiter missions. It will dramatically increase the amount of data that surface missions such as the Mars Science Laboratory can send to Earth. It will operate in two radio bands and carry an optical communications terminal to demonstrate use of a laser beam for interplanetary communications.

  The present decade represents the most intense scientific exploration of a neighboring world since the Apollo era, focusing on the search for ancient and modern habitats through the history of water. The next decade will witness the transition from "following the water" to a "search for building blocks of life" -- in other words, following the carbon. Alternate pathways of exploration have been defined by the science community to be responsive to the unknown and unpredictable discoveries of this decade; they include intensive analysis by robotic craft at Mars, and analysis of Mars sam-ples in Earth laboratories designed to provide definitive evidence of biological building blocks. Scout missions will continue to augment and complement the program in innovative ways to fill identified science measurement gaps.