Mars Exploration Rover

NASA's Mars Exploration Rover (MER) Mission is an ongoing robotic mission of exploring Mars, that began in 2003 with the sending of two rovers — MER-A Spirit and MER-B Opportunity — to explore the Martian surface and geology.

Primary among the mission's scientific objectives is to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program which includes three previous successful landers: the two Viking landers in 1976 and Pathfinder in 1997.

The total cost of building, launching, landing and operating the rovers on the surface for the initial 90 Martian-day primary mission was US$820 million.[1] Since the rovers have continued to function for over five years after landing they have received five mission extensions with the fifth mission extension, which was granted in October 2007, being until the end of 2009.[1][2] The total cost of the first four mission extensions was $104 million and the fifth mission extension is expected to cost at least $20 million.[1] In July of 2007, Martian dust storms blocked sunlight to the rovers and threatened the ability of the craft to gather energy through their solar panels, causing engineers to fear that one or both of them might be permanently disabled. However, the dust storms lifted, allowing them to resume operations.[3]

In recognition of the vast amount of scientific information amassed by both rovers, two asteroids have been named in their honor: 37452 Spirit and 39382 Opportunity.

The mission is managed for NASA by the Jet Propulsion Laboratory, which designed, built and is operating the rovers.

Objectives.

The scientific objectives of the Mars Exploration Rover mission are to:

*Search for and characterize a variety of rocks and soils that hold clues to past water activity. In particular, samples sought will include those that have minerals deposited by water-related processes such as precipitation, evaporation, sedimentary cementation or hydrothermal activity.
* Determine the distribution and composition of minerals, rocks, and soils surrounding the landing sites.
* Determine what geologic processes have shaped the local terrain and influenced the chemistry. Such processes could include water or wind erosion, sedimentation, hydrothermal mechanisms, volcanism, and cratering.
* Perform calibration and validation of surface observations made by Mars Reconnaissance Orbiter instruments. This will help determine the accuracy and effectiveness of various instruments that survey Martian geology from orbit.
* Search for iron-containing minerals, identify and quantify relative amounts of specific mineral types that contain water or were formed in water, such as iron-bearing carbonates.
* Characterize the mineralogy and textures of rocks and soils and determine the processes that created them.
* Search for geological clues to the environmental conditions that existed when liquid water was present.
* Assess whether those environments were conducive to life.

During the next two decades, NASA will conduct several missions to address whether life ever arose on Mars. The search begins with determining whether the Martian environment was ever suitable for life. Life, as we understand it, requires water, so the history of water on Mars is critical to finding out if the martian environment was ever conducive to life. Although the Mars Exploration Rovers do not have the ability to detect life directly, they are offering very important information on the habitability of the environment in the planet's history.



Naming of Spirit and Opportunity.

The Spirit and Opportunity rovers were named through a student essay competition. The winning entry was by Sofi Collis, a third-grade Russian-American student from Arizona.

I used to live in an orphanage. It was dark and cold and lonely. At night, I looked up at the sparkly sky and felt better. I dreamed I could fly there. In America, I can make all my dreams come true. Thank you for the 'Spirit' and the 'Opportunity.'
— Sofi Collis, age 9

Prior to this, during the development and building of the rovers, they were known as MER-1 (Opportunity) and MER-2 (Spirit). Internally NASA also uses the mission designations MER-A (Spirit) and MER-B (Opportunity) based on the order of landing on Mars (Spirit first then Opportunity).