Several spacecraft, including orbiters, landers, and rovers have been sent to Mars by the former Soviet Union (Russia), the United States, Europe, and Japan. The purpose has always been to study the surface, geology, and climate of our solar system's fourth planet and moons Deimos and Phobos. Approximately two-thirds of all missions failed either before concluding or even embarking on their journeys. The high failure rate is officially attributable to technical problems. The few successful missions emphasized their overlooked value and substantiated the immeasurable significance of such fundamental objectives.

The following are some triumphant missions that led to what is currently at Mars:

Launched in 1964, NASA's Mariner 4 celebrated the first successful flyby mission in 1965. The first landers were launched in 1971; Mars 2 and Mars 3, of the Soviet Mars probe program, reached the surface but lost contact after seconds. In contrast, the Mars 3 orbiter sent back a large volume of data until 1972. Then NASA launched the historic Viking program in 1975, which also consisted of two successful orbiters and landers. Viking 1 and Viking 2 remained operational for six years and three years, respectively.

In 1988 the Soviet Phobos Project launched to Mars and Phobos. While contact was lost with Phobos 1, Phobos 2 collected valuable data until it was thwarted before being set to release two moon landers. The US launched Mars Global Surveyor in 1996, which revealed the presence of water within the past 14 to 16 years. MGS remained successful through 2006.

NASA also launched its Pathfinder lander and Sojourner rover of the Discovery Program in 1996 to explore the surface in 1997. It was first in a series of outstanding missions that included robotic exploration vehicles on the Red Planet. The 2001 Mars Odyssey orbiter is the next accomplishment. It currently uses imagers and spectrometers to scan for past or present water and volcanic activity. NASA approved a mission extension through 2008 to allow observation of year-to-year differentiations in dust storms, clouds, and polar ice.

The 2003 launch of the Mars Express program by the European Space Agency is the next big win. Although its Beagle 2 lander was declared lost, the ESA's Mars Express orbiter still provides extensive mineralogical and atmospheric composition mapping that includes analysis of the atmosphere and its interaction between both the subsurface and the interplanetary medium.

NASA again succeeded in 2003 with the launch of its twin rovers Spirit and Opportunity, as the primary components of the Mars Exploration Program. Since 2004 the robotic rovers have been traversing the Martian landscape daily, investigating the planet's past water activity. Nearly 85% of data from the rovers reaches Earth via daily communications relay by the Odyssey orbiter.

The lift-off of the Mars Reconnaissance Orbiter probe in 2005 awarded NASA another achievement. The multipurpose spacecraft began its two-year science mission in 2006 to analyze Martian ice, stratigraphy, landforms, and minerals. It also monitors weather and surface conditions on a daily basis. Remarkably, MRO is testing a new telecommunications system that will eventually transfer more data to Earth from Mars than all previous interplanetary missions combined.

MRO will not only serve as a highly capable relay satellite, but it will also map the terrain with high-resolution cameras in order to select landing sites for future missions. The intricate orbiter will assist mission planners of the next Mars missions, including the Phoenix Scout lander (a Mars Society concept) and the Mars Science Laboratory rover. Phoenix is a multiagency, polar lander that launched August 2007 and is set to land 25 May 2008. MSL is a large NASA rover scheduled to launch December 2009 and land October 2010.