NASA and the European Space Agency, or ESA, have embarked on a joint program to explore Mars in the coming decades and have selected five science instruments - including one from the University of Arizona - for the first mission.
The ExoMars Trace Gas Orbiter, scheduled to launch in 2016, is the first of three joint robotic missions to the Red Planet. It will study the chemical makeup of the Martian atmosphere with a 1,000-fold increase in sensitivity over previous Mars orbiters.
The mission will focus on trace gases, including methane, which could be potentially geochemical or biological in origin and be indicators for the existence of life on Mars. It also will serve as an additional communications relay for Mars surface missions beginning in 2018.
A stereo camera called the High Resolution Stereo Color Imager, or HiSCI, operated by the UA, will be a part of the orbiter.
"The HiSCI camera will provide us with the very best color and stereo imaging of Mars we have ever seen, so we can find and study surface changes," said Alfred McEwen, a professor of planetary science at the UA who leads the HiSCI project.
HiSCI will be operated by the same team at the UA's Lunar and Planetary Lab, or LPL, that has been acquiring images from Mars in stunning detail using the High Resolution Imaging Science Experiment, or HiRISE, camera that is orbiting Mars.
HiSCI's color images will be much wider (more than 5 miles) than those of HiRISE (less than 1 mile), which will allow researchers to see much more of the Martian surface and changes that are occurring there.
Having the three-dimensional and color information from HiSCI also will add to the value of existing high-resolution images from HiRISE, according to Shane Byrne, assistant professor at LPL and deputy principal investigator on the HiSCI project.
HiRISE can take images at a finer resolution, but its color-imaging capabilities are limited and it requires two orbital passes, which can be months apart, to acquire a stereo image of a feature on Mars' surface. HiSCI will be able to take a stereo pair of images in the same pass, which eliminates unwanted variation, such as differences in sun angle at the time each image is shot.
In addition to using HiSCI to image previously unknown features, the UA team plans to take a closer look at features already imaged with the HiRISE camera and other Mars orbital experiments and to search for new candidate landing sites to follow up on new discoveries.
"Over the last four years, HiRISE has photographed only 1 percent of the Martian surface, but it already has discovered many unexpected features and phenomena," Byrne said. "It's exciting to think of all the great new discoveries we'll make with HiSCI's greater color and stereo capabilities."
NASA and ESA invited scientists worldwide to propose the spacecraft's instruments. The five selected were from 19 proposals submitted in January. Both agencies evaluated the submissions and chose those with the best science value and lowest risk.
The instrument selection begins the first phase of the new NASA-ESA alliance for future ventures to Mars. The other instruments selected for the mission and their respective principal investigators are:
- Mars Atmosphere Trace Molecule Occultation Spectrometer - a
spectrometer designed to detect very low concentrations of the
molecular components of the Martian atmosphere; Paul Wennberg,
California Institute of Technology in Pasadena, Calif.