Laser-Induced Remote Sensing

The Laser-Induced Remote Sensing for Chemistry and Micro-Imaging instrument will identify atomic elements in martian rocks. Image credit: NASA/JPL-Caltech/LANL/J.-L. Lacour, CEA

Looking at rocks and soils from a distance, ChemCam will fire a laser and analyze the elemental composition of vaporized materials from areas smaller than 1 millimeter on the surface of Martian rocks and soils. An on-board spectrograph will provide unprecedented detail about minerals and microstructures in rocks by measuring the composition of the resulting plasma -- an extremely hot gas made of free-floating ions and electrons.

ChemCam will also use the laser to clear away dust from Martian rocks and a remote camera to acquire extremely detailed images. The camera can resolve features 5 to 10 times smaller than those visible with cameras on NASA's two Mars Exploration Rovers that began exploring the red planet in January 2004. In the event the Mars Science Laboratory rover can't reach a rock or outcrop of interest, ChemCam will have the capability to analyze it from a distance.

From a distance of 1 to 9 meters (3.3 to 30 feet), ChemCam will be able to:

• rapidly identify the kind of rock being studied (for example, whether it is volcanic or sedimentary);
  
  
• determine the composition of soils and pebbles;
  
  
• measure the abundance of all chemical elements, including trace elements and those that might be hazardous to humans;
  
  
• recognize ice and minerals with water molecules in their crystal structures;
  
  
• measure the depth and composition of weathering rinds on rocks; and,
  
  
• provide visual assistance during drilling of rock cores.
  
  

The ChemCam instrument has two parts: a mast package and a body unit. On the mast will be a telescope to focus the laser and the camera, a laser for vaporizing surfaces, and a remote micro-imager. The mast package can be tilted or rotated as needed for optimum viewing of the rock.

Light from the telescope will travel along a fiber-optic link to a body unit inside the rover. The body unit will carry three spectrographs for dividing the plasma light into its constituent wavelengths for chemical analysis. The body unit will also have its own power supply and an electronic interface to the rover's central computer system.

Developing the ChemCam instruments for NASA are the Los Alamos National Laboratory (LANL) and the Centre d'Etude Spatiale des Rayonnements (CESR), with major contributions from JPL, Ocean Optics Inc., and the Commissariat a l'Energie Atomique (CEA).