591 Tickalara Trough
605 Lagrange
612 Windjana
613 Self Portrait
615 Windjana
627 Windjana Drill Hole Cuttings
629 Stephen
722 BonanzaKing2
722 BonanzaKing1
726 BonanzaKing2
802 Garlock
805 Pelona
805 Ricardo
808 Rosamond
809 Mojave
810 Potatoe
813 Punchbowl
814 Anaverde
814 Afton_Canyon
815 Topanga
819 Mescal
824 Puente
828 Chinle Oblique
868 Self Portrait
869 Mojave Chunk
882 Self Portrait Extension
905 Telegraph_Peak
930 Coalville
935 APXS vein material raster
937 Back of Coalville
938 APXS vein material raster extension
946 Kern_Peak
946 Vein Material T-shaped
948 Vein Material Stereo mosaic
974 Bigfork
998 Ronen
1028 Big_Arm
1031 Dog's eye of Missoula Area
1032 Clark
1057 Buckskin
1065 Rover Undercarriage inspection
1092 Lebo
1105 Sacajawea
1105 Winnipeg
1114 Big_Sky
1126 Self Portrait
1157 Augusta
1166 Swakop
1182 track_wall
1182 Weissrand
1202 Greenhorn Sieved Sample
1228 Gobabeb Scoop 1
1228 Self-portrait
1241 Self Portrait Supplemental frames
1254 Kuiseb
1275 Palmhorst
1275 Palmwag
1277 Sperrgebiet
1277 Klein_Aub
1278 Sperrgebiet
1279 Khomas
1325 Lianshulu
1327 Lubango post-sieve discard pile
1330 Okoruso
1338 Self Portrait
1341 Kwakwas
1341 Okoruso Site
1344 Impalila
1351 Dog's eye of Nauaspoort
1371 Berg_Aukas
1380 Koes
1407 Robotic arm workspace
1407 Boulder with targets named Tumba and Funda
1409 Funda
1418 Marimba
1457 Quela
1463 Self Portrait
1463 Ombomboli
1474 Utuseb
1474 Jwaneng
1482 Cassongue
1491 Sebina
1504 Thrumcap
1504 Wonderland
1514 Southwest_Harbor
1518 Folly_Island
1523 Seawall
1531 Precipice
1552 The_Anvil
1566 Old_Soaker Workspace
1566 Old_Soaker
1566 Bar_Island
1570 Valley_Cove ( and Gilley_Field)
1581 Smalls_Falls
1589 Cape_Elizabeth
1591 Munsungun
1593 Misery
1611 Patch_Mountain
1614 Chain_Lakes
1614 Spider_Lake
1634 Canada_Falls
1668 Morancy_Stream
1675 Lookout_Point
1679 Maple_Spring
1702 Fern_Spring
1714 Prays_Brook
1715 Old_Mill_Brook
1727 Jones_Marsh
1734 Pecks_Point
1749 Ile_Damour
1788 Dumplings_Island
1811 Mount_Ephraim
1865 Barberton
7.4.3.3 MAHLI Landscape Imaging
When the zoom capability was descoped from the Mastcams, the rover lost its ability to capture wide views of the Martian landscape in color using a single frame. MAHLI is now the widest-angle color camera on the rover that can do landscape imaging, so soon after landing the team planned to use MAHLI during traverses to take single pre- or post-drive images to document the changing landscape. MAHLI takes these images from its stowed position, so they can be captured on sols when available resources restrict use of the arm. When stowed, the camera looks over the rover’s left shoulder (measured about 110° to the left of the rover’s forward direction), and images are rotated about 150° counterclockwise from horizontal. MAHLI performed its first infinity-focus test on sol 274, just before leaving Yellowknife Bay. The experiments determined the best-focus motor position for landscape imaging (a motor count of 12552), and throughout the drive to Mount Sharp MAHLI took a single photo at this motor count after most drives. An example of a MAHLI landscape image is shown in Figure 7.17. The last such routine landscape image was on sol 1112, but the team continues to occasionally request such photos when they’re expected to show a subject of scientific or engineering interest.
Figure 7.17. A MAHLI stowed-position landscape image from sol 952, in “Artist’s Drive” beyond Pahrump Hills. Image 0952MH0003250050304147E01. NASA/JPL-Caltech/MSSS.
7.4.3.4 MAHLI engineering support images
MAHLI is regularly used to examine hardware on the rover, in particular the rover’s wheels, because the mast-mounted cameras can only see the right side wheels partially and the left side wheels not at all. MAHLI documented the first visible puncture in a rover wheel on sol 411, and has monitored wheel condition since then (see section 4.6.4). MAHLI also monitors dust accumulation on the REMS ultraviolet sensor and has been used as a diagnostic tool for the condition of the REMS wind booms, dust accumulation on the ChemCam and ChemCam windows, and interior of the CheMin inlet.
7.4.3.5 MAHLI self-portraits
Self-portraits are a special rover self-examination product. They are mosaics of more than 50 MAHLI images, taken with the arm held out and in front of the rover. A MAHLI self-portrait has become part of the standard set of documentation activities performed at sample sites, though the mission forgoes the self-portrait if pressed for time.
The rover usually holds MAHLI about 2 meters above the bottoms of the rover wheels (that is, at “eye level”) for self-portraits. To capture the images for the mosaic, the arm rotates the camera in such a way as to keep MAHLI fixed in one location with only its optical axis pivoting. MAHLI takes images for the upper half of the mosaic first, then repositions the arm to keep it from blocking the camera’s view and takes the photos for the lower half. Rover planners time the mosaic carefully to keep not only the arm but also its cast shadows out of view as much as possible, because the moving arm shadows make assembly of the mosaic difficult.
At the Buckskin drill site on sol 1065, the rover planners implemented a special position for the self-portrait, with MAHLI held in nearly the same position as it is for wheel imaging. The low perspective gives the impression of the rover looming over the observer. Figure 7.18 shows some of the MAHLI frames used to create the Buckskin self-portrait, which also graces the cover of this book.
Figure 7.18. Top: A subset of the MAHLI frames used to produce the mosaic printed on the cover of this book, taken at Buckskin on sol 1065. Bottom: View of the turret taken from the left front Hazcam during the Buckskin self-portrait sequence. A small local low in topography allowed the rover planners to create this unusual low-angle view. MAHLI is located on the upper right side of the turret in this view. NASA/JPL-Caltech/MSSS/Emily Lakdawalla.
Table 3.3 documents all sampling activities, including self-portraits at sample sites. At John Klein, Windjana, Confidence Hills, and Quela, the MAHLI team took a full self-portrait on one sol, before drilling, and then supplemented the self-portrait with extra frames taken on subsequent sols to document the change at the site after sampling activities were complete. Two self-portraits have included imaging of the mast head in more than one position. At Windjana, MAHLI imaged the head both facing the camera and looking down at the drill site. At Okoruso, MAHLI imaged the head both facing the camera and facing away, looking at Mount Sharp.
7.4.4 Anomalies and precautions
Through sol 1800, MAHLI has had no hardware issues apart from the dusting of the originally transparent lens cover during the rover’s descent to the surface. However, on one occasion, a MAHLI problem caused a robotic arm fault, and on another, a MAHLI issue required a 2-week recovery including 8 sols in which the dust cover was open.
The first of these anomalies occurred on sol 615. MAHLI was imaging the recently drilled Windjana mini-drill hole when the camera head faulted, causing the arm to be unable to move while the rover awaited analysis and further instruction from Earth. During the 2-sol wait, MAHLI was held just 5 centimeters above the fresh drill cuttings, with its cover open. The fault had to do with real-time MAHLI image compression producing unexpectedly large image files. MAHLI was returned to normal operation on sol 627.
The second anomaly occurred on Sol 1619. In this case, the MAHLI cover failed to open completely. As in the previous fault, the arm didn’t move, pending further instruction from the ground. The dust cover stayed open for 8 sols. Inspection using the Mastcams, Navcams, and Hazcams, followed by careful testing of the dust cover on subsequent sols, showed normal operation. Investigation revealed that while MAHLI was operating within its allowable temperature range, the fault occurred at a temperature lower than MAHLI had ever been commanded to operate before. Flight rules were modified to require MAHLI operation at higher temperatures, with the low-temperature limit set at –20°C.19
On sols 764, 774, and 1575, the arm has faulted during MAHLI imaging, leaving the MAHLI cover open for a few sols during recovery. To avoid long periods of the MAHLI cover being left open as a result of an arm fault, MAHLI now requires the cover to be closed for all imaging performed within a few sols before holiday or conjunction periods. That leaves enough time for recovery and cover close before a command moratorium.
Toward the end of September 2016, as Curiosity cleared the Murray buttes and re-entered the Bagnold dune field and its sand transport corridor, repeat imaging of sandy spots showed dramatic wind-induced sand motion. Blowing sand presents little hazard to MAHLI (sand grains are too heavy to stick to the window), but finer materials like drill tailings could be a concern. If blowing sand grains strike dust or drill cuttings on the ground, the fine material can be lofted into the wind and then stick electrostatically to MAHLI’s sapphire window. Between the Sebina, Precipice, and Ogunquit Beach sample sites in late 2016 and early 2017, the MAHLI team performed all close-up imaging with the cover closed. And as a precaution while driving across windy sand transport corridors, the MAHLI team modified their operations procedures to open the dust cover with the camera aimed down, so that any sand particles that do strike the front of MAHLI’s optics will (hopefully) bounce or roll off.
REFERENCES
Alexander D and Deen R (2015) Mars Science Laboratory Project Software Interface Specification: Camera & LIBS Experiment Data Record (EDR) and Reduced Data Record (RDR) Data Products, version 3.5
Bell J et al (2012) Mastcam multispectral imaging on the Mars Science Laboratory rover: Wavelength coverage and imaging strategies at the Gale crater field site. Paper presented at the 43rd Lunar and Planetary Science Conference, The Woodlands, Texas, 19–23 Mar 2012
Bell J et al (2017) The Mars Science Laboratory Curiosity rover Mast Camera (Mastcam) instruments: Pre-flight and in-flight calibration, validation, and data archiving. Earth and Space Sci, DOI: 10.1002/2016EA000219
Edgett K et al (2012) Curiosity’s Mars Hand Lens Imager (MAHLI) investigation. Space Sci Rev 170:259–317, DOI: 10.1007/s11214-012-9910-4
Edgett K et al (2015) Curiosity’s robotic arm-mounted Mars Hand Lens Imager (MAHLI): Characterization and calibration status. In: MSL MAHLI Technical Report 0001, Version 2, DOI: 10.13140/RG.2.1.3798.5447
Garvin J et al (2014) Sedimentology of Martian gravels from MARDI twilight imaging: Techniques. Paper presented at the 45th Lunar and Planetary Science Conference, The Woodlands, Texas, 17–21 Mar 2014
Garvin J et al (2015) Terrain analysis of Mars at cm-scales from MARDI stereo imaging. Paper presented at the 46th Lunar and Planetary Science Conference, The Woodlands, Texas, 16–20 Mar 2015
Ghaemi F T (2009) Design and fabrication of lenses for the color science cameras aboard the Mars Science Laboratory Rover. Optical Engineering 48:10, DOI: 10.1117/1.3251343
Kinch K et al (2013) Dust on the Curiosity mast camera calibration target. Paper presented at the 44th Lunar and Planetary Science Conference, The Woodlands, Texas, 18–22 Mar 2013
Maki J et al (2012) The Mars Science Laboratory engineering cameras. Space Sci Rev 170:77–93, DOI: 10.1007/s11214-012-9882-4
Malin M et al (2009) The Mars Science Laboratory (MSL) Mars Descent Image (MARDI) Flight Instrument. Paper presented at the 40th Lunar and Planetary Science Conference, The Woodlands, Texas, 23–27 Mar 2009
Malin M et al (2010) The Mars Science Laboratory (MSL) mast-mounted cameras (Mastcams) flight instruments. Paper presented at the 41st Lunar and Planetary Science Conference, The Woodlands, Texas, 1–5 Mar 2010
Malin M et al (2017) The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions. Earth and Space Sci, DOI: 10.1002/2016EA000252
Minitti M et al (2015) Mapping the Pahrump Hills outcrop using MARDI sidewalk mosaics. Paper presented at the 46th Lunar and Planetary Science Conference, The Woodlands, Texas, 16–20 Mar 2015
Schieber J et al (2013) The final 2 1/2 minutes of terror – what we learned about the MSL landing from the images taken by the Mars Descent Imager. Paper presented at the 44th Lunar and Planetary Science Conference, The Woodlands, Texas, 18–22 Mar 2013.
Wentworth C (1922) A scale of grade and class terms for clastic sediments. J Geol 30:377–392, DOI: 10.1086/622910
Yingst R A et al (2014) Cameras on Landed Payload Robotic Arms – MAHLI and Mars and Lessons Learned from One Mars Year of Operations. Paper presented to the International Workshop on Instrumentation for Planetary Missions (IPM-2014), 4–7 Nov 2014
Yingst R A et al (2016) MAHLI on Mars: Lessons learned operating a geoscience camera on a landed payload robotic arm. Geosci Instrum Method Data Syst 5:205–217, DOI:10.5194/gi-5-205-2016
Footnotes
1Prior to landing, there was no peer-reviewed paper describing Mastcam or MARDI. Mastcam was described in two Lunar and Planetary Science Conference abstracts: Malin et al. (2010) and Bell et al. (2012). Also useful is Alexander and Deen (2015). Two peer-reviewed articles were in preparation as this book was being written: Bell et al. (2017) and Malin et al. (2017). Because Mastcam shares its electronics, detector, and focal mechanism design with MAHLI, the Edgett et al. (2012) MAHLI paper is also informative.
2Michael Malin, personal communication, email dated April 14, 2017
3Bell et al. (2017)
4Onboard interpolation uses the Malvar-He-Cutler linear interpolation algorithm
5Bell et al. (2017)
6Michael Malin, personal communication, email dated April 14, 2017
7Kinch K et al (2013) Dust on the Curiosity mast camera calibration target. Paper presented at the 44th Lunar and Planetary Science Conference, The Woodlands, Texas, March 18-22, 2013
8Mark Lemmon, personal communication, email dated June 15, 2017
9The MARDI instrument is described in Malin et al. (2009) and Malin et al. (2017)
10Schieber et al. (2013)
11Garvin et al. (2014)
12Garvin et al. (2015)
13Minitti et al. (2015)
14The paper of record for MAHLI is Edgett et al. (2012); two other valuable resources are Edgett et al. (2015) and Yingst et al. (2016)
15Ghaemi (2009)
16The MAHLI Principal Investigator’s Notebooks are available for download from Ken Edgett’s page on Researchgate: https://www.researchgate.net/profile/Ken_Edgett/publications
17Mars Science Laboratory (MSL) Software Interface Specification for Camera & LIBS Experiment Data Record (EDR)
and Reduced Data Record (RDR) Data Products version 3.5, August 5, 2014
18Yingst R A et al (2014) Cameras on Landed Payload Robotic Arms – MAHLI and Mars and Lessons Learned from One Mars Year of Operations. Paper presented to the International Workshop on Instrumentation for Planetary Missions (IPM-2014), 4-7 Nov 2014
19Ashwin Vasavada, interview dated March 10, 2017, and Ken Edgett, email dated April 10, 2017
© Springer International Publishing AG, part of Springer Nature 2018
Emily LakdawallaThe Design and Engineering of CuriositySpringer Praxis Bookshttps://doi.org/10.1007/978-3-319-68146-7_8
8. Curiosity’s Environmental Sensing Instruments
Emily Lakdawalla1
(1)The Planetary Society, Pasadena, CA, USA
8.1 INTRODUCTION
Environmental sensing instruments include the Rover Environmental Monitoring Suite (REMS), a package of several meteorological instruments, and the Radiation Assessment Detector (RAD), which measures the radiation dose at the surface. Dynamic Albedo of Neutrons (DAN) straddles the boundary between remote and environmental sensing; in passive mode it detects ambient neutrons, and in active mode it can also bombard the surface with neutrons to explore for subsurface water and light elements.
The environmental instruments operate mostly in the background, quietly taking data at routine intervals. Sequencing them mostly involves commanding when to retrieve the data from Mars. They can operate during periods like holidays and conjunctions when the rover is otherwise inactive, and some components operate even while the rover is asleep.
The Design and Engineering of Curiosity Page 31