June 25, 2013
Testing Mars Lasers In The Atacama Desert
Michael Harper for redOrbit.com – Your Universe Online
Looking for the closest representation of otherworldly environments on Earth? Look no further than the Atacama desert. It covers a large strip of the Pacific coast west of the Andes, spanning four South American countries. One swath of this desert found in Chile is commonly compared to the Martian surface and has been used by NASA to test tools designed to search for life in a harsh environment. Now, scientists from Washington University in St. Louis will take to the Atacama desert to try out their latest laser technology.Alian Wang, a research professor of Earth and Planetary Sciences at Washington University will be testing out a laser slated to ride aboard a rover in a 2020 mission to Mars. For the past 18 years, Wang and other researchers at Washington University in St. Louis (WUSTL) have been collaborating with NASA’s Jet Propulsion Laboratory (JPL) to create a laser Raman spectrometer called the Mars Microbeam Raman Spectrometer, or MMRS. According to Wang, this spectrometer offers a clearer view of the rock and soil samples being analyzed.
“Compared to other spectroscopies, Raman spectroscopy returns a very clear spectrum,” said Wang in a statement. “So if you analyze a mixture (rock or soil) you see peaks for each mineral phase and organic molecule. You don’t have to do complicated spectral processing to identify what’s in the sample. So compared to other spectroscopies, its very diagnostic.”
The MMRS was originally scheduled to visit Mars onboard the Mars rovers Spirit and Opportunity, but these rovers were downgraded following the incidents with the Polar Lander and Climate Orbiter. As the MMRS was the newest technology on the rovers, it was removed as a part of the downsizing.
A new rover called Zoe is scheduled to make its own trip to the Red Planet in seven years, however, and NASA has just given Wang $3 million to put the MMRS through its paces and make sure it’s ready to ride. Thus she’s sending a colleague on site to the Atacama desert along with the Carnegie Mellon University team responsible for the Zoe rover to stress test the MMRS and look for any weak points.
Wang visited the desert herself last year to test her spectrometer and said the extreme conditions of the Atacama presented issues which they never would have had the chance to observe otherwise.
“The heat generated by cooling the Raman spectrometer’s detector is dissipated by a cooling fan. When we came to the Atacama we were sometimes as high as 4,500 meters (14,800 feet) above sea level. The air is so thin at that altitude, the fan labored to get rid of the heat. That’s one lesson we learned,” said Wang. “Of course it will be different on Mars where the atmosphere is much thinner, but we learned where the instrument is vulnerable.”
As Zoe traverses areas of the desert geographically similar to Mars, it will scoop soil samples from the surface as well as bore down deep beneath the surface. These mixtures of rock and soil will then be analyzed by the MMRS which will be powered remotely by Wang thousands of miles away in her St. Louis offices.