Shooting Rocks on Mars
Science fiction laser weapons blast enemy aliens, but ChemCam, an instrument Los Alamos developed in collaboration with NASA and the French Space Agency, will aim its laser at Mars rocks.
Delivered in August 2010 to NASA's Jet Propulsion Laboratory in California, ChemCam is being installed on the Mars Science Laboratory, a six-wheeled rover named Curiosity that will be launched on a rocket in 2011 and lowered by cable to the Mars surface from a hovering drop ship in 2012. NASA is arming the rover with numerous scientific instruments in hopes of learning if the planet was ever able to support life. Curiosity will examine the Mars environment for two Earth years (one Mars year).
ChemCam comprises two of the rover's instruments: (1) a remote micro-imager for taking high-resolution pictures and (2) laser-induced breakdown spectroscopy (LIBS) equipment for chemically analyzing rocks and soil. The Laboratory's Roger Wiens, whose Space Science and Applications team miniaturized the LIBS technology for space, will lead a team of U.S. and French scientists operating ChemCam and checking the LIBS results from Mars.
Curiosity, an SUV-size rover, can remotely analyze otherwise-inaccessible rock and soil samples with its LIBS laser from Los Alamos.
LIBS works remotely. From a mast atop the rover (see illustration), its high-energy pulsed laser can hit targets up to 7 meters (about 23 feet) away, dislodging atoms at very high energy—"They're just zinging off of there," says Wiens—and exciting them to an electrically charged state: a plasma dot that gives off light as it loses energy. A telescope (also on the mast) collects the light and focuses it onto the end of a fiber-optic cable linked to the LIBS spectrometers in Curiosity's body. The spectrometers resolve the light into wavelengths that reveal the specific types and amounts of elements in the rock. Pre-analysis laser pulses can even remove dust and weathered coatings to prepare the rock for analysis.
"And LIBS recognizes almost all known elements," says Wiens. It's this elemental information that will characterize the planet's makeup and pinpoint samples interesting enough to be physically sampled by other Curiosity instruments.
NASA is also considering a proposal to use LIBS to search for water at the Moon's south pole, and Los Alamos's Laboratory Directed Research and Development program is funding experiments that combine LIBS with Raman spectroscopy, a related technology, for possible use on a future Venus lander.
In this issue...
- Dynamic Vision
DARHT FULFILLS ITS DESTINY
- Solar Smart Grid in the Atomic City
TEST BED FOR LOCAL CONTROL OF RENEWABLE ENERGY
EXPOSING AND EXPLOITING THE SECRET LIFE OF SOIL
Clean Air and Abundant Fuel
Shooting Rocks on Mars
Better Fuel Cell Membrane Materials