CRISM

CRISM
Name	CRISM
Mission	Mars Reconnaissance Orbiter
Operator	Jet Propulsion Laboratory
Manufacturer	Malin Space Science Systems
Launch	2005
Type	Imaging spectrometer
Wavelength	Visible and near-infrared
Resolution	Up to 18 m/pixel (targeted)

CRISM is an imaging spectrometer flown on the Mars Reconnaissance Orbiter designed to map mineralogy on Mars using visible and near-infrared spectroscopy. The instrument produced high-spatial- and high-spectral-resolution datasets used by teams from the Jet Propulsion Laboratory, NASA, and international partners to identify hydrated minerals, alteration products, and lithologic units across plains, craters, and layered deposits. CRISM data informed interpretations by planetary scientists studying aqueous processes, stratigraphy, and potential past habitable environments linked to missions such as Viking program payload analyses and Mars Science Laboratory rover investigations.

Overview

CRISM operated as part of the payload on Mars Reconnaissance Orbiter, alongside instruments like HiRISE, CTX, and SHARAD. The instrument combined dispersive optics and focal plane arrays developed through collaborations including Malin Space Science Systems and the Johns Hopkins University Applied Physics Laboratory. CRISM measured reflected sunlight across visible and near-infrared bands to detect diagnostic absorption features produced by minerals such as phyllosilicates, sulfates, carbonates, and iron oxides, linking orbital spectroscopy to ground truth provided by Spirit (rover), Opportunity (rover), and Curiosity (rover) operations. The dataset supplemented regional mapping by missions like Mars Global Surveyor and comparative planetology studies referencing results from Lunar Reconnaissance Orbiter and Voyager program heritage instruments.

Instrument Design and Specifications

CRISM was a hyperspectral imaging spectrometer featuring a pushbroom scanner, a grating spectrometer, and cooled detectors optimized for 0.36–3.92 μm coverage. Optical design components were produced under project oversight from Jet Propulsion Laboratory engineers and calibration teams affiliated with Malin Space Science Systems and academic partners such as Brown University. The instrument delivered two primary acquisition modes: targeted hyperspectral imaging at high spatial sampling and multispectral mapping at lower spatial resolution for global coverage. Key specifications included high spectral sampling with hundreds of channels, high signal-to-noise ratios achieved through thermal control and detector cooling, and onboard electronics for data handling developed leveraging heritage from instruments on Mars Odyssey and Mars Express. Pointing control integrated with the Mars Reconnaissance Orbiter attitude system and used spacecraft star trackers and reaction wheels for precise targeting over features including phyllosilicate-bearing terrains and sulfate-rich layered deposits.

Mission Operations and Data Processing

Mission operations were conducted by the Jet Propulsion Laboratory flight teams in coordination with science teams at academic institutions and international partners. CRISM observing campaigns targeted landing sites examined by the Mars Exploration Rover mission, outflow channels, and stratigraphic exposures such as those within Valles Marineris and ancient highlands. Raw telemetry were downlinked via the Deep Space Network and ingested into pipelines developed by the CRISM Investigation Team and the Planetary Data System. Data processing steps included radiometric calibration, photometric correction referencing solar incidence geometry, thermal emission removal for longer wavelengths, and spectral smile and striping corrections. Higher-level products comprised spectral parameter maps, spectral library matches, and mineralogical index mosaics used by researchers conducting regional mapping and by mission planners assessing prospective landing sites for missions like Mars 2020.

Scientific Objectives and Key Discoveries

Primary objectives centered on detecting minerals diagnostic of past aqueous alteration, constraining the timing and extent of hydration, and identifying stratigraphic contexts for habitability. CRISM identified widespread phyllosilicate-bearing units in Noachian terrains, confirming aqueous alteration hypotheses proposed from telescopic spectra and earlier orbital data from Mars Global Surveyor. The instrument mapped magnesium- and iron-rich clays, polyhydrated and monohydrated sulfates, and localized carbonate occurrences that framed discussions linking Martian alteration to terrestrial analogs studied at institutions such as Smithsonian Institution research programs. CRISM contributed to discoveries of hydrated silica and alteration halos around impact craters, detection of seasonal frost and dust-coated surfaces, and spectral evidence for perchlorate-associated signatures tied to findings by the Phoenix (spacecraft) lander and in situ rover chemistry. Results influenced site selection and science goals for Curiosity (rover) and Perseverance (rover) investigations and informed models of early Mars climate and aqueous geochemistry developed by research groups at California Institute of Technology and Massachusetts Institute of Technology.

Calibration and Validation

Calibration efforts were led by teams at Jet Propulsion Laboratory and partner laboratories, using onboard calibration lamps and vicarious calibration targets observed on Mars, and laboratory spectral libraries maintained by academic centers such as Brown University and University of Oxford. Validation combined CRISM spectra with in situ measurements from Spirit (rover), Opportunity (rover), Curiosity (rover), and elemental data from instruments developed at institutions like NASA Ames Research Center. Cross-calibration with contemporaneous orbital instruments such as OMEGA on Mars Express and multispectral imagers on Mars Odyssey helped quantify systematic biases and refine mineral identifications. Ongoing community validation used spectral endmember libraries curated by groups at USGS and university spectroscopy labs.

Data Access and Usage

CRISM data products are archived in the Planetary Data System and distributed through science team portals hosted by Jet Propulsion Laboratory and collaborating institutions. Users include planetary geologists, spectroscopists, astrobiologists, and mission planners at organizations such as NASA, European Space Agency, and universities worldwide. Data formats follow PDS standards and are compatible with analysis tools developed by the community, with spectral libraries from USGS and software packages maintained at academic centers enabling mineral mapping, spectral unmixing, and stratigraphic correlation studies that continue to inform Mars exploration strategy and comparative planetology research.

Category:Mars Reconnaissance Orbiter instruments