For a record-breaking 15 years now, the Mars Odyssey spacecraft has orbited Mars and provided an unprecedented global view of the planet.

Originally, the Mars mission planned for 2001 was to be named “Mars Surveyor 2001.” The mission consisted of two parts: an orbiter and a lander.

However, after the failures of the Mars Polar Lander and the Mars Climate Orbiter in 1999, NASA scrubbed the lander portion of the mission. NASA renamed the orbiter “2001 Mars Odyssey” after Arthur C. Clarke’s science fiction book “2001: A Space Odyssey.”

The 2001 Mars Odyssey mission launched on April 7, 2001 via Boeing’s Delta II 7925 rocket and arrived at its Mars orbit on October 24, 2001. The primary science phase of the mission lasted approximately 917 Earth days.

The mission supported the four main goals of the Mars Exploration Program:

• To determine whether life ever arose on Mars
• To characterize the climate of Mars
• To characterize the geology of Mars
• To prepare for the eventual human exploration of the planet

To fulfill these goals, the Mars Odyssey orbiter brought three instruments with it: THEMIS, GRS and MARIE.

Conceptual image of the Mars Odyssey spacecraft in science orbit configuration showing THEMIS, MARIE, and GRS (with boom deployed). Credit: NASA/JPL-Caltech

THEMIS Camera Images Help Scientists Understand Mineral Distribution on Mars

The Thermal Emission Imaging System (THEMIS) is a camera that maps Mars in both the visible and infrared wavelengths of the electromagnetic spectrum. THEMIS has taken more than 21,000 images, each image covering an area of approximately 12 x 12 miles.

The resolution of these images is good enough to show objects about the size of a semi-truck. The infrared wavelengths show the surface mineralogy of Mars.

The goal of THEMIS was to understand the distribution of minerals with respect to the landforms on the planet. In 2010, the images collected from THEMIS allowed scientists to produce a global map of Mars with the highest resolution ever achieved to date.

GRS Tool Maps Distribution of Chemical Elements on Mars

When cosmic rays hit the surface of Mars, materials on the surface emit gamma rays as unique signatures of energy. The Gamma Ray Spectrometer (GRS) measures the amount of gamma rays coming from these surface elements.

The GRS maps the distribution of many elements on Mars, including hydrogen, silicon, iron, potassium, thorium, and chlorine. Using data from GRS’s detection of hydrogen, NASA personnel created a global map of water distribution on Mars. In 2008, the Phoenix lander confirmed the presence of water when it found evidence of water ice just below the Martian surface.

MARIE Studies Radiation Levels in Space and around Mars

Conceptual image of the Mars Odyssey spacecraft in science orbit configuration showing THEMIS, MARIE, and GRS (with boom deployed). Credit: NASA/JPL-Caltech

The Mars Radiation Environment Experiment (MARIE) studied radiation levels while this spacecraft was on the trip to Mars and while it was in Martian orbit. Knowledge of radiation levels is very important for developing the technologies to protect the first people to travel to Mars.

While there are similar instruments that measure radiation on the International Space Station (ISS), MARIE is the first instrument of its kind to travel beyond the protection of the Earth’s magnetosphere.  MARIE measured the amount of radiation in Mars orbit as approximately twice that experienced in ISS orbit.

Comparison of radiation in Mars orbit and ISS orbit. Credit: NASA/JPL-Caltech

Unfortunately, MARIE failed in October 2003 after a period of very intense solar activity.

While the primary science mission has been over for many years, the Mars Odyssey spacecraft still orbits the planet gathering information about seasonal changes on the planet. It also serves as a crucial communications relay station for rovers on Mars.

In fact, Mars Odyssey relays more than 90 percent of the data received from NASA’s Spirit and Opportunity rovers. Both Mars Odyssey and the Mars Reconnaissance Orbiter share the relay responsibility for NASA’s Curiosity rover.

NASA scientists estimate that Mars Odyssey has enough fuel to continue orbiting the planet until 2025. In addition to Mars Odyssey, there are currently a number of other NASA missions studying Mars including the Mars Reconnaissance Orbiter, Mars Exploration Rovers, Mars Express (along with ESA), Mars Science Laboratory, and Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft.  Future missions are being planned to learn more about Mars and, hopefully, support human exploration of the planet in the near future.

About the Author

This is an article by Dr. Nancy Taylor, Ph.D.

She is a Faculty Member,School of Science, Technology, Engineering and Math, American Public University. Dr. Nancy Taylor is an instructor in the STEM school at American Public University. She holds a B.S. in geology and mechanical engineering from Hofstra University and an M.S. in Environmental Sciences from the University of Virginia. Other academic credentials include an A.M. and a Ph.D. in Earth and planetary sciences from Washington University in St. Louis.