In January 2004, two robotic geologists named Spirit and Opportunity landed on opposite sides of the red planet. With far greater mobility than the 1997 Mars Pathfinder rover, these robotic explorers have trekked for miles across the Martian surface, conducting field geology and making atmospheric observations. Carrying identical, sophisticated sets of science instruments, both rovers have found evidence of ancient Martian environments where intermittently wet and habitable conditions existed.
A full sized model of the Mars Exploration Rover is currently on display at the Steven F. Udvar-Hazy Center in Chantilly, VA. More details about the spacecraft are located on its label on the main floor in the Space Hangar.
When did Spirit and Opportunity launch from Earth and land on Mars?
What were the mission objectives for Spirit and Opportunity?
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 "ground truth" -- calibration and validation -- of surface observations made by Mars 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.
Launch: Spirit launched on June 10, 2003 (UTC) , and Opportunity on July 8, 2003 (UTC) from Kennedy Space Center, Florida.
Mars Landing: Spirit landed on Mars January 3, 2004 (UTC) at Gusev Crater and Opportunity landed on January 25, 2004 (UTC) at Meridiani Planum, Mars.
Mission Status: Inactive Both rovers exceeded their planned 90-day mission lifetimes by many years. Spirit lasted 20 times longer than its original design until it concluded its mission in 2010. Opportunity has worked on Mars longer than any other robot—nearly 15 years. The rover last communicated with Earth on June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover’s location on Mars.
What were some of the findings from Spirit and Opportunity's missions?
In 2015, Opportunity broke the record for extraterrestrial travel by driving more than the distance of a marathon, with a total of 28.06 miles (45.16 kilometers).
Landing in a crater, Opportunity scored a "hole in one" by finding the mineral hematite, which typically forms in water. Water is key to life as we know it. Yet, acidic water soaked this area in Mars' ancient past, making conditions harder for life to thrive.
At a place called Comanche, Spirit found rocks ten times richer in key chemicals (magnesium and iron carbonates) than any other Martian rocks studied before. These rocks formed when Mars was warm and wet (had a thicker carbon-dioxide atmosphere and near-neutral-pH water).
While dragging a wheel, Spirit churned up soil and found 90 percent pure silica at "Home Plate." On Earth, this kind of silica usually exists in hot springs or hot steam vents, where life as we know it often finds a hot, happy home.
Spirit discovered that an ancient volcano erupted at "Home Plate," the rover's final resting place. Together, powerful steam eruptions from heated underground water produced some explosive volcanism. While violent, these extreme conditions can support microbial life on Earth.
Near the rim of Endeavor Crater, Opportunity found bright-colored veins of gypsum in the rocks. These rocks likely formed when water flowed through underground fractures in the rocks, leaving calcium behind. A slam-dunk sign that Mars was one more hospitable to life than it is today!
Opportunity found the most compelling signs of a watery past on Mars: clay minerals formed in neutral-pH water. Of all the places studied by the twin rovers, this environment at Endeavor Crater once had the friendliest conditions for ancient microbial life.
What were some of the instruments on Spirit and Opportunity and what were their purposes?
Panoramic Camera - determine the mineralogy, texture, and structure of the local terrain.
Miniature Thermal Emission Spectrometer - identify promising rocks and soils for closer examination and for determine the processes that formed Martian rocks. The instrument is designed to look skyward to provide temperature profiles of the Martian atmosphere.
Mössbauer Spectrometer - close-up investigations of the mineralogy of iron-bearing rocks and soils.
Alpha Particle X-Ray Spectrometer - close-up analysis of the abundances of elements that make up rocks and soils.
Microscopic Imager - obtain close-up, high-resolution images of rocks and soils.
Rock Abrasion Tool - remove dusty and weathered rock surfaces and expose fresh material for examination by instruments onboard.
What were the primary power sources for Spirit and Opportunity?
The main source of power for each rover comes from a multi-panel solar array. When fully illuminated, the rover solar arrays generate about 140 watts of power for up to four hours per sol (a Martian day). The rover needs about 100 watts (equivalent to a standard light bulb in a home) to drive. The capability of the solar arrays to generate power will likely be reduced to about 50 watts of power due to anticipated dust coverage on the solar arrays
Two lithium-ion rechargeable batteries that provide energy for the rover when the sun is not shining, especially at night.