For two decades, the longest-lived spacecraft on the Red Planet has helped locate water ice, assess landing sites, and study the mysterious months of the planet.
NASA’s 2001 Mars Odyssey spacecraft was launched 20 years ago on April 7, making it the oldest spacecraft still working on the red planet. The orbiter, named after Arthur C. Clarke’s classic SF SF novel “The Space Odyssey” (Clarke blessed its use before launch), was sent to map the composition of the Martian surface, providing a window into the past so that humans science could divide how the planet evolved.
But much more has been done, discovering water ice holes, serving as a crucial communications link for other spacecraft and helping pave the way not only for safer landings but also for future astronauts.
Here is a partial list of the many achievements of the Odyssey.
Martian ice mapping
The two decades of Odyssey data have been an advantage for researchers working to determine where water ice is trapped on the planet. Understanding the water cycle on Mars – a planet that was once much wetter than Earth – provides information about how it has changed over time: How does water move around the planet today? Does the tilt of the planet affect where the ice is stable? The discoveries of the Odyssey helped to eliminate these questions.
“Before the Odyssey, we didn’t know where this water was stored on the planet,” said project scientist Jeffrey Plaut of NASA’s Jet Propulsion Laboratory in Southern California, which is leading the Odyssey mission. “I first detected it from orbit and later confirmed that it was there using the Phoenix lander.”
Water ice deposits are also needed to help astronauts survive on Mars and provide fuel to their spacecraft. (In fact, astronauts were the focal point of an instrument aboard the Odyssey that measured the amount of space radiation it would have to face before it ceased to function in 2003.) The orbiter finds water ice using its gamma-ray spectrometer detector. which turned out to be a hydrogen-capable hunter close to the surface – a proxy for water ice. GRS measures the amount of different elements on the Martian surface and also serves as a node in NASA’s interplanetary gamma-ray detection (GRB) network, which identifies GRB’s source locations for tracking astronomical observations.
What Mars is made of
Look at almost any Martian surface mapping study and it probably includes Odyssey data. For many years, the most complete global maps of Mars were made using Odyssey’s infrared camera, called the Thermal Emission Imaging System or THEMIS. The camera measures surface temperature day and night, allowing scientists to determine what physical materials, such as rock, sand or dust, exist. Its data reveal the presence of these materials based on how they are heated or cooled during a Martian day.
The net effect of the value of two decades of all that mapping? Scientists have not only used the data to map valley networks and craters, but have also been able to spot sandstone, iron-rich rocks, salts and more – discoveries that help provide a deeper insight into its history. Mars. “It’s hard to overstate how THEMIS’s global map has filled the gaps in our knowledge,” said Laura Kerber of JPL, Odyssey’s deputy scientist.
Safer landings
THEMIS has sent back more than 1 million images since it began orbiting Mars. The images and maps it produces highlight the presence of hazards, such as topographic features and boulders, but also help ensure the safety of future astronauts by showing the location of resources, such as water ice. This helps the scientific community Mars and NASA decide where to send landers and rovers – including the Perseverance rover, which reached on February 18, 2021.
Routine home calls
From the beginning, Odyssey has served as a long-distance call center for NASA rovers and landings, sending its data back to Earth as part of the Mars Relay Network. The idea of evil Mars dates back to the 1970s, when the two Viking landers sent scientific data and images through an orbiter back to Earth. An orbiter can carry radios or antennas capable of sending back more data than a surface spacecraft. But the Odyssey made the process routine when it began transmitting data to and from NASA’s Spirit and Opportunity rovers.
“When the twin rovers landed, the success of UHF data transmission was a game changer,” said Chris Potts of JPL, Odyssey’s mission manager.
Every day, the rovers could go somewhere new and send fresh images back to Earth. Through a relay like the Odyssey, scientists obtained more data earlier, while the public obtained more images on Mars to get excited. The Odyssey held over 18,000 relay sessions. These days, he shares the task of communicating with NASA’s Mars Reconnaissance Orbiter and MAVEN, together with ESA (European Space Agency) Trace Gas Orbiter.
Colorful candy months
The Odyssey did such a thorough job of studying the Martian surface that scientists began to turn the THEMIS camera to capture unique views of the moons of Mars Phobos and Deimos. As with the Martian surface, studying the thermophysics of each month helps scientists determine the properties of the materials on their surfaces. Such information may provide sight in their past: it is not clear whether the moons are asteroids or captured pieces of Mars, thrown from the surface by an ancient impact.
Future missions, such as the Japanese Space Agency’s Marsian Moons eXploration (MMX) spacecraft, will seek to land in the coming months. In the distant future, missions could even create bases for astronauts. And if they do, they will be based on data from an orbiter that began its odyssey at the beginning of the millennium.
THEMIS was built and operated by Arizona State University in Tempe. Odyssey’s gamma-ray spectrometer was provided by the University of Arizona, Tucson, the Los Alamos National Laboratory and the Russian Institute for Space Research. The main contractor for the Odyssey project, Lockheed Martin Space in Denver, developed and built the orbiter. Mission operations are conducted jointly by Lockheed Martin and JPL, a division of Caltech in Pasadena.
For more information about the Odyssey, visit:
https://mars.nasa.gov/odyssey/
https://www.nasa.gov/mission_pages/odyssey/index.html
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, California.
818-393-2433
[email protected]