Chemistry and Camera complex (ChemCam) is a suite of

remote sensing Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...

instruments on

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

for the ''Curiosity'' rover. As the name implies, ChemCam is actually two different instruments combined as one: a

laser-induced breakdown spectroscopy Laser-induced breakdown spectroscopy (LIBS) is a type of atomic emission spectroscopy which uses a highly energetic laser pulse as the excitation source. The laser is focused to form a plasma, which atomizes and excites samples. The formation of ...

(LIBS) and a Remote Micro Imager (RMI) telescope. The purpose of the LIBS instrument is to provide elemental compositions of rock and soil, while the RMI will give ChemCam scientists high-resolution images of the sampling areas of the rocks and soil that LIBS targets. The LIBS instrument can target a rock or soil sample from up to away, vaporizing a small amount of it with about 30 5-nanosecond pulses from a 1067 nm

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

laser and then observing the spectrum of the light emitted by the vaporized rock.

Overview

ChemCam has the ability to record up to 6,144 different wavelengths of ultraviolet, visible, and infrared light. Detection of the ball of luminous plasma is done in the visible, near-UV and near-infrared ranges, between 240 nm and 800 nm. The first initial laser testing of the ChemCam by ''Curiosity'' on Mars was performed on a rock, N165 ("Coronation" rock), near

Bradbury Landing Bradbury Landing is the August 6, 2012, landing site within Gale (crater), Gale crater on planet Mars of the Mars Science Laboratory (MSL) Curiosity rover, ''Curiosity'' rover. On August 22, 2012, on what would have been his 92nd birthday, NAS ...

on August 19, 2012. Using the same collection optics, the RMI provides context images of the LIBS analysis spots. The RMI resolves objects at distance, and has a field of view covering at that distance. The RMI has also been used to take images of distant geologic features and landscapes. The ChemCam instrument suite was developed by the

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development Laboratory, laboratories of the United States Department of Energy National Laboratories, United States Department of Energy ...

and the French CESR laboratory. The flight model of the mast unit was delivered from the French

CNES CNES () is the French national space agency. Headquartered in central Paris, the agency is overseen by the ministries of the Armed Forces, Economy and Finance and Higher Education, Research and Innovation. It operates from the Toulouse Spac ...

.ChemCam Status April, 2008
. Los Alamos National Laboratory.

Instrumentation

Laser Induced Breakdown Spectroscopy

ChemCam marks the first use of Laser Induced Breakdown Spectroscopy ( LIBS) as part of a planetary science mission. The laser is positioned on the mast of the

Curiosity Curiosity (from Latin , from "careful, diligent, curious", akin to "care") is a quality related to inquisitive thinking, such as exploration, investigation, and learning, evident in humans and other animals. Curiosity helps Developmental psyc ...

rover and focused by the telescope that also resides on the mast, while the spectrometer is housed in the rover's body. Typically, the laser fires 30 shots at a single point, gathering spectroscopic readings from the vaporized rock for each laser shot, and samples multiple points on a chosen target. For bedrock observations, the first 5 shots of a point are discarded as they are considered to be contaminated by Martian dust. The remaining shots of one point are averaged together for chemical composition calculations. It is common for there to be 9 or 10 points of analysis on any given target, but this is not always the case. Some targets have as few as 4 points while some targets have 20 points.

Remote Micro-Imager

The Remote Micro-Imager is primarily used to capture high-resolution, black and white images of ChemCam targets for context and documentation. Usually, an image of the target of interest is captured before and after the laser is fired. Often, the laser makes "LIBS pits" that can be visible in the RMI to show where the laser sampled specifically on a particular target. The resolution of the RMI is higher than the black and white navigational camera (navcam) and the color mast cameras (mastcam).

Long Distance Imaging

The RMI is primarily used to obtain close-up images of targets sampled by ChemCam, but it can also be used to gather high-resolution images of distant outcrops and landscapes. The RMI has a higher spatial resolution than the mastcam M100 camera, which is a color camera also capable of imaging nearby objects or distant geologic features. The RMI has been used by the mission for reconnaissance of up-coming terrain as well as imaging distant features such as the rim of

Gale Crater Gale is a crater, and probable dry lake, at in the northwestern part of the Aeolis quadrangle on Mars. It is in diameter and estimated to be about 3.5–3.8 billion years old. The crater was named after Walter Frederick Gale, an amateur a ...

Scientific contributions

ChemCam has been used, in conjunction with other instruments of the

rover, to make advancements in understanding the chemical composition of rocks and soils on

. LIBS makes it possible to detect and quantify the major oxides: SiO₂, Al₂O₃, FeO_T, MgO, TiO₂, CaO, Na₂O, and K₂O of bedrock targets. There are distinguishable geologic units determined from orbital analyses that have been confirmed by averaged bedrock compositions determined from ChemCam and other instruments aboard Curiosity. The identification is based on multivariate PLS and PCA models classified using SIMCA with calibration models made using "''The Unscramble'' r" software. ChemCam has also quantified soil chemistry. ChemCam has seen two distinct soil types at Gale crater: a fine-grained mafic material that is more representative of global

Martian soil Martian regolith is the fine blanket of unconsolidated, loose, heterogeneous superficial deposits covering the surface of Mars. The term ''Martian soil'' typically refers to the finer fraction of regolith. So far, no samples have been returned to ...

s or dust and a coarse-grained felsic material that originates from local Gale crater bedrock. ChemCam has the capability to measure minor or trace elements such as lithium, manganese, strontium, and rubidium. ChemCam has measured MnO up to 25 wt% in fracture fills that suggests Mars was once a more oxygenating environment.

Images

Image:Mars Curiosity Rover-Coronation Rock-N165.jpg, First target on

of the ChemCam laser analyzer on the ''Curiosity'' rover ( "Coronation" rock, August 19, 2012). Image:PIA16089.jpg, First laser spectrum of

chemical elements A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in i ...

from ChemCam on ''Curiosity'' ( "Coronation" rock, August 19, 2012). Image:PIA17592-MarsCuriosityRover-IthacaRock-20131030.jpg, Target on

of the ChemCam laser analyzer on ''Curiosity''
closeup
( "Ithaca" rock, October 30, 2013). Image:PIA17592-MarsCuriosityRover-IthacaRock-Spectrum-20131030.jpg, Laser spectrum of

from ChemCam on ''Curiosity'' ( "Ithaca" rock, October 30, 2013). Image:PIA18396-MarsCuriosityRover-WinnipesaukeeRock-20140625.jpg, Target on

of the ChemCam laser analyzer on ''Curiosity'' ( "Winnipesaukee" rock, June 8, 2014). Image:PIA18401-MarsCuriosityRover-NovaRock-LaserSpark-20140712.jpg, First laser spark imaged on Mars by ''Curiosity'' ( "Nova" rock; July 12, 2014
video (01:07)
. Image:PIA18388-MarsCuriosityRover-NovaRock-ChemCam-20140712.jpg, Laser spectrum of

from ChemCam by ''Curiosity'' ( "Nova" rock; July 12, 2014).

References

External links

*
''Curiosity'' home page
at NASA.gov
How Does ChemCam Work?
at MSL-ChemCam.com {{Mars Mars imagers Mars Science Laboratory instruments Spacecraft instruments Space science experiments