The Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) is a Facility Instrument (i.e., government‐furnished equipment operated by a science team not responsible for design and fabrication) ...designed, built, and operated by Malin Space Science Systems and the MRO Mars Color Imager team (MARCI). CTX will (1) provide context images for data acquired by other MRO instruments, (2) observe features of interest to NASA's Mars Exploration Program (e.g., candidate landing sites), and (3) conduct a scientific investigation, led by the MARCI team, of geologic, geomorphic, and meteorological processes on Mars. CTX consists of a digital electronics assembly; a 350 mm f/3.25 Schmidt‐type telescope of catadioptric optical design with a 5.7° field of view, providing a ∼30‐km‐wide swath from ∼290 km altitude; and a 5000‐element CCD with a band pass of 500–700 nm and 7 μm pixels, giving ∼6 m/pixel spatial resolution from MRO's nearly circular, nearly polar mapping orbit. Raw data are transferred to the MRO spacecraft flight computer for processing (e.g., data compression) before transmission to Earth. The ground data system and operations are based on 9 years of Mars Global Surveyor Mars Orbiter Camera on‐orbit experience. CTX has been allocated 12% of the total MRO data return, or about ≥3 terabits for the nominal mission. This data volume would cover ∼9% of Mars at 6 m/pixel, but overlapping images (for stereo, mosaics, and observation of changes and meteorological events) will reduce this area. CTX acquired its first (instrument checkout) images of Mars on 24 March 2006.
The Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) investigation will use a 2-megapixel color camera with a focusable macro lens aboard the rover, Curiosity, to investigate the ...stratigraphy and grain-scale texture, structure, mineralogy, and morphology of geologic materials in northwestern Gale crater. Of particular interest is the stratigraphic record of a ∼5 km thick layered rock sequence exposed on the slopes of Aeolis Mons (also known as Mount Sharp). The instrument consists of three parts, a camera head mounted on the turret at the end of a robotic arm, an electronics and data storage assembly located inside the rover body, and a calibration target mounted on the robotic arm shoulder azimuth actuator housing. MAHLI can acquire in-focus images at working distances from ∼2.1 cm to infinity. At the minimum working distance, image pixel scale is ∼14 μm per pixel and very coarse silt grains can be resolved. At the working distance of the Mars Exploration Rover Microscopic Imager cameras aboard Spirit and Opportunity, MAHLI’s resolution is comparable at ∼30 μm per pixel. Onboard capabilities include autofocus, auto-exposure, sub-framing, video imaging, Bayer pattern color interpolation, lossy and lossless compression, focus merging of up to 8 focus stack images, white light and longwave ultraviolet (365 nm) illumination of nearby subjects, and 8 gigabytes of non-volatile memory data storage.
On 7 June 2021, Juno crossed the orbital path of Jupiter’s moon Ganymede, flying within 1,046 km of the surface. Juno’s low‐light‐sensitive Stellar Reference Unit (SRU) navigation camera captured an ...image of the satellite’s dark side in a region of Xibalba Sulcus illuminated solely by Jupiter‐shine. Collected at high incidence angle with 670–920 m/pixel resolution, the image reveals terrain morphology, ejecta, and numerous small craters that cannot be discerned in the Voyager imagery used for the USGS global geologic map of Ganymede. The Juno data enable improved mapping of Ganymede’s surface and reinterpretation of material and crater ages in a region previously characterized as light “undivided” material due to poor image resolution. The illumination conditions achieved by the SRU observation geometry also reveal the detailed morphology of a 270‐km elongated bright feature in this area. These newly resolved features contribute to an improved understanding of Ganymede’s complex history.
Plain Language Summary
On 7 June 2021, the Juno spacecraft flew within about 1,000 km of the surface of Jupiter’s largest moon, Ganymede. The Mission used their sensitive navigation camera to photograph the moon’s dark side where it was lit only by scattered sunlight from Jupiter. This new imaging approach revealed multiple surface features, including a patchwork of different surface textures (such as grooved terrain), several craters, and ejecta deposits. These features had not been visible in images collected by previous spacecraft. Well‐resolved details of the surface structure help us understand Ganymede’s history and the processes responsible for how it appears today. One feature may either be ejecta from a very distant crater or scars from the pieces of a broken up comet that collided with Ganymede.
Key Points
Juno’s Stellar Reference Unit imaged Ganymede at high resolution and incidence angle while the surface was illuminated by Jupiter‐shine
Grooved material, ejecta, and multiple craters are now resolved, enabling improved mapping of a 2 × 105 km2 region in Xibalba Sulcus
The unique morphology of a possible 270‐km scar from comet fragments, or a highly isolated distal ray from Tros, is revealed
The Scanning Habitable Environments with Raman and Luminescence for Organics
and Chemicals (SHERLOC) is a robotic arm-mounted instrument on NASA’s Perseverance
rover. SHERLOC has two primary ...boresights. The Spectroscopy boresight generates
spatially resolved chemical maps using fluorescence and Raman spectroscopy coupled to
microscopic images (10.1 μm/pixel). The second boresight is a Wide Angle Topographic
Sensor for Operations and eNgineering (WATSON); a copy of the Mars Science Laboratory
(MSL) Mars Hand Lens Imager (MAHLI) that obtains color images from microscopic
scales (∼13 μm/pixel) to infinity. SHERLOC Spectroscopy focuses a 40 μs pulsed deep UV
neon-copper laser (248.6 nm), to a ∼100 μm spot on a target at a working distance of ∼48
mm. Fluorescence emissions from organics, and Raman scattered photons from organics
and minerals, are spectrally resolved with a single diffractive grating spectrograph with a
spectral range of 250 to ∼370 nm. Because the fluorescence and Raman regions are naturally
separated with deep UV excitation (<250 nm), the Raman region ∼ 800 – 4000 cm−1
(250 to 273 nm) and the fluorescence region (274 to ∼370 nm) are acquired simultaneously
without time gating or additional mechanisms. SHERLOC science begins by using an Autofocus
Context Imager (ACI) to obtain target focus and acquire 10.1 μm/pixel greyscale
images. Chemical maps of organic and mineral signatures are acquired by the orchestration
of an internal scanning mirror that moves the focused laser spot across discrete points on
the target surface where spectra are captured on the spectrometer detector. ACI images and
chemical maps (< 100 μm/mapping pixel) will enable the first Mars in situ view of the spatial
distribution and interaction between organics, minerals, and chemicals important to the
assessment of potential biogenicity (containing CHNOPS). Single robotic arm placement
chemical maps can cover areas up to 7x7 mm in area and, with the < 10 min acquisition
time per map, larger mosaics are possible with arm movements. This microscopic view of
the organic geochemistry of a target at the Perseverance field site, when combined with
the other instruments, such as Mastcam-Z, PIXL, and SuperCam, will enable unprecedented
analysis of geological materials for both scientific research and determination of which samples
to collect and cache for Mars sample return.
The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal ...plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam‐34 has an f/8, 34 mm focal length lens, and the M‐100 an f/10, 100 mm focal length lens. The M‐34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M‐100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M‐34 can focus from 0.5 m to infinity, and the M‐100 from ~1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the ~2 m tall Remote Sensing Mast, have a 360° azimuth and ~180° elevation field of regard. Mars Descent Imager is fixed‐mounted to the bottom left front side of the rover at ~66 cm above the surface. Its fixed focus lens is in focus from ~2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of ~70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.
Key Points
The Mars Descent Imager, an f/3 9.7 mm, 2 M pixel color camera operated autonomously during landing taking a descent video at 4 frames/second
Mastcam‐34 f/8, 34 mm camera takes <1600 × 1200 pixel images in broad and narrowband color over a field 20° × 15° at a scale of 218 μrad/pixel
Mastcam‐100 f/10, 100 mm, f/10 takes <1600 × 1200 pixel images in broad and narrowband color over a field 6.8° × 5.1° at 74 μrad/pixel scale
Plain Language Summary
Paper describes the Mast cameras and Descent Imager on the Mars Science Laboratory Curiosity rover. Cameras take 2 megapixel color images that can be compressed in both JPEG lossy and predictive lossless format. One of the two Mastcams has a 34 mm lens, equivalent to a consumer camera 35 mm lens, and the other has a 100 mm lens, similar to consumer camera telephoto lens. The descent imager has a very wide angle lens (~90°) and takes wide angle pictures. The Mast cameras are mounted on an azimuth elevation mast so they can scan around the rover and into the sky. The Descent camera always points down. The Mast cameras have different filters to allow for scientific color imaging as well as standard color imaging as performed by consumer cameras.
The successful 2020 launch and 2021 landing of the National Aeronautics and Space Administration’s (NASA) Perseverance Mars rover initiated the first phase of the NASA and European Space Agency (ESA) ...Mars Sample Return (MSR) campaign. The goal of the MSR campaign is to collect scientifically interesting samples from the Martian surface and return them to Earth for further study in terrestrial laboratories. The MSR campaign consists of three major spacecraft components to accomplish this objective: the Perseverance Mars rover, the Sample Retrieval Lander (SRL) and the Earth Return Orbiter (ERO). Onboard the ERO spacecraft is the Capture, Containment and Return System (CCRS). CCRS will capture, process and return to Earth the samples that have been collected after they are launched into Mars orbit by the Mars Ascent Vehicle (MAV), which is delivered to Mars onboard the SRL. To facilitate the processing of the orbiting sample (OS) via the CCRS, we have designed and developed a vision system to determine the OS capture orientation. The vision system is composed of two cameras sensitive to the visible portion of the electromagnetic spectrum and two illumination modules constructed from broadband light emitting diodes (LED). Vision system laboratory tests and physics-based optical simulations predict CCRS ground processing will be able to correctly identify the OS post-capture orientation using only a single vision system image that is transmitted to Earth from Mars orbit.
During its first year of operation, the Perseverance rover explored the cratered and fractured floor of Jezero crater on Mars. Here, we report the use of the Scanning Habitability Environments with ...Raman and Luminescence for Organics and Chemicals (SHERLOC) imaging system that includes two high-resolution cameras, the Autofocus and Contextual Imager (ACI) and Wide Angle Topographic Sensor for Operations and eNgineering (WATSON). ACI is a fixed focus gray scale imager with a resolution of 10.1 μm/pixel whereas WATSON is a variable field of view, variable focus imager capable of resolution down to 14 μm/pixel. WATSON is a reflight of the MArs Hand Lens Imager (MAHLI) imager and has similar capabilities. During first-time activities, WATSON was used to support both science and engineering operations related to sample and abrasion patch assessment and sample collection and caching. WATSON also documented the deployment of the Ingenuity helicopter. The Crater Floor Campaign identified two primary rock units, the Máaz formation and the Séítah formation, which have been interpreted as lava flows and an olivine cumulate, respectively. Interpretation of rock textures with WATSON and ACI images was limited to abraded surfaces because unmodified outcrop surfaces (herein termed “natural surfaces”) show high degrees of dust covering, wind abrasion, and coating by secondary mineral products. WATSON and ACI images support the hypothesis that the material of both the Máaz and Séítah formations consists of largely aqueously altered mafic materials with varying igneous origins.
The Mars Science Laboratory Curiosity rover conducted a reconnaissance traverse across the Pahrump Hills outcrop within Gale crater from Sols 780–797. During the traverse, the Mars Descent Imager ...(MARDI) acquired a continuous imaging record of primary and secondary sedimentary features throughout the outcrop. The characteristics of the features (laminae, resistant features, fractures, gray clasts) and their spatial distribution provide insight into the processes that contributed to the formation of Pahrump Hills. Thin, regular laminae (mm-scale) are ubiquitous in the bedrock, implying that depositional processes at that scale did not change appreciably during deposition of the mudstone succession at Pahrump Hills. Higher bedrock slopes correlate with undulatory bedrock surfaces, bedrock with elevated Mg contents, and fractures exhibiting wide, raised edges. These collective features are consistent with increased erosional resistance caused by greater quantities of erosionally-resistant, Mg-bearing cement within the bedrock permitted by coarser grain sizes. Resistant features exhibit a range of morphologies, elevated Mg contents, and do not deflect laminae within the bedrock. Their characteristics implicate the involvement of Mg-enriched fluids in a late diagenetic overprint affecting the bedrock. The variations of fracture fill and edge morphologies and chemistries further suggest repeated fracturing and fluid interaction events within the strata exposed at Pahrump Hills. Gray clasts strongly resemble fragments eroded from sandstone horizons interspersed throughout the Pahrump Hills outcrop.
•A MARDI sidewalk mosaic was used to systematically map the Pahrump Hills outcrop.•MARDI identified primary and secondary sedimentary features throughout the outcrop.•MARDI determined the spatial distribution of the sedimentary features.•The features record the depositional and diagenetic history of Pahrump Hills.
SHERLOC is an arm-mounted fluorescence and Raman spectrometer that was recently selected to be part of the payload for the next proposed NASA rover mission to Mars, scheduled for launch in 2020. ...SHERLOC enables non-contact, spatially resolved, high sensitivity detection and characterization of organics and minerals on the Martian surface. The investigation goals are to assess past aqueous history, detect the presence and preservation potential of biosignatures, and support the selection of samples for caching and potential return to Earth.
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