MSL MAHLI Science Reports

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MSL - MAHLI Science Reports
MAHLI Instrument Information

Curiosity completes first Night Imaging Session with MAHLI

January 23, 2013

After working on Mars for 165 Sols, Curiosity has finally used the Mars Hand Lens Imager for its first nightly imaging session using artificial illumination to examine a target inside Yellowknife Bay, a depression in the Glenelg area, that the rover is currently exploring.

Curiosity’s first night imaging session started on Sol 165 about 2.5 hours after sunset and had a duration of about 70 minutes – involving a great deal of robotics.

The first step was to perform a checkout of the Mars Hand Lens Imager’s LEDs that were used to illuminate the MAHLI Calibration Target located on the forward portion of the rover. Nighttime image capabilities are provided by two sets of two white light LEDs. Each pair is individually activated to provide redundancy to the illumination system. Two Ultraviolet LEDs (365nm) are being used to search for fluorescent materials during night-imaging sessions. Those UV LEDs are not calibrated tools and are used on a ‘best-efforts’ basis.

Photo: NASA/JPL/Caltech/MSSS

MAHLI took two images of its Calibration Target, one with the white LEDs and one with the UV LEDs.

Photo: NASA/JPL/Caltech/MSSS

MAHLI Calibration Target illuminated by the white LEDs

Photo: NASA/JPL/Caltech/MSSS

MAHLI Calibration Target illuminated by the UV LEDs, notice the fluorescent Color Calibration plate (processed image)

Photo: NASA/JPL/Caltech/MSSS

Raw, unprocessed sky image. All bright objects and streaks are noise and hot pixels.

Afterwards, the the robotic arm was moved to point MAHLI to the sky and take several images of the sky with different exposure times and focus settings. The raw images show a large amount of noise which dominates over any features of the actual picture, but faint streaks can be seen when processing the images which could represent stars/planets. The images will be discussed further when processed images and more information is released by Malin Space Science Systems and NASA.

Next, MAHLI was positioned above a target on the Martian Surface. The Instrument was used to take close-up images of a vein in one of the rocks in its vicinity. Images were taken at different distances. At the two closest standoff distances, MAHLI first took an image with both white LEDs before taking two images – one using the right LEDs and one with the left LEDs powered up. This is done to create shadow images that show the three-dimensional properties of the target. When that was complete, MAHLI activated the UV LEDs, taking two sets of five images under UV illumination using different exposure times. Assessing the fluorescence of the material allows scientists to identify fluorescent minerals and materials that could be present in targets.

Photo: NASA/JPL/Caltech/MSSS

GIF of acquired Shadow Images

Photo: NASA/JPL/Caltech/MSSS

MAHLI images illuminated by its white LEDs (left) and UV LEDs (right)

After taking images for more than one hour, Curiosity went back to its nominal overnight mode to save power.

All MAHLI Images from Sol 165 can be found here.

MAHLI's first Science Targets on the Martian Surface

October 4, 2012

After completing Commissioning Activity Period 2, MSL was a fully commissioned Rover, ready to begin nominal science operations on the surface of Mars. Since then, the MAHLI Instrument on the turret of MSL's Robotic Arm has examined a number of targets, acquiring lots of close-up images of these targets. This image report features MAHLI images of MSL's two Contact Science Targets up to Sol 56 with context images provided by the MastCams. For more on MAHLI Commissioning, refer to the section below and the MSL Mission Updates Site.

Sols 44 through 48 - Jake Matijevic

The rock is about 25 centimeters tall and 40 centimeters wide giving Curiosity the opportunity to conduct contact science which requires the robotic arm to push its instruments against the rock. This first contact science target has been named "Jake Matijevic" in honor of Jacob Matijevic (1947-2012) who was the surface operations systems chief engineer for the Mars Science Laboratory Mission. Matijevic was also a leading engineer on all the previous rovers, making major contributions to rover technology and paving the way for the operation of rovers on Mars.

Contact Science on Jake Matijevic was performed with MAHLI as well as APXS - Alpha Particle X-Ray Spectrometer. In addition, ChemCam was used for cross calibration with APXS and the MastCams were used to provide context imagery.

Photo: NASA/JPL/Caltech

Photo: NASA/JPL/Caltech/MSSS

MastCam Context Image

Photo: NASA/JPL/Caltech/MSSS

The MAHLI Image above combines photographs taken from different distances to the target. The three exposures were taken using the adjustable focus feature of MAHLI and were taken at distances of 25, 5 and 2.5 centimeters. "MAHLI reveals that the target rock has a relatively smooth, gray surface with some glinty facets reflecting sunlight and reddish dust collecting in recesses in the rock," NASA said in a statement. Jake Matijevic appears to be a uniform rock.

Photo: NASA/JPL/Caltech/MSSS

Sol 54 - Bathurst Inlet

Photo: NASA/JPL/Caltech/MSSS

Bathurst Inlet was examined on Sols 54 and 55 using the Contact Instruments MAHLI (images above and below) and APXS as well as ChemCam and the MastCams. The Rock is dark gray and it is evident that the MAHLI Instrument is unable to resolve the crystals in it, meaning that the grains or crystals, if any are contained in the rock at all, must be smaller than about 80 microns in size. The MAHLI context image (left) was taken with MAHLI at a distance of 27 centimeters to the acquiring an image showing about 16 by 12 centimeters of the target. This image has a resolution of about 105 microns per pixel.

The ultra-close-up image (right) was acquired when the MAHLI Lens was just 4 centimeters from the target with the view covering only 3.3 by 2.5 centimeters. The resolution of this frame is 21 microns per pixel. Some wind-blown dust particles have accumulated on the surface of the rock. Both images were produced by the on-board focus merging feature of MAHLI.

Right: Animated NavCam View of the Contact Science Sequence executed on Sol 54 including imaging of Bathurst Inlet with MAHLI and APXS.

Frames: NASA/JPL/Caltech

MastCam Context Image

Photo: NASA/JPL/Caltech/MSSS

MAHLI Image Product - Onboard Processing

Photo: NASA/JPL/Caltech/MSSS

Depth Map

Photo: NASA/JPL/Caltech/MSSS

Recap: MAHLI Commissioning and Checkouts

October 2, 2012

The MSL Mars Hand Lens Imager has started regular operations on Mars after the Curiosity rover performed checkouts of the instrument as part of Commissioning Activity Phase 2 during Sols 30 through 37. After opening its dust cover for the first time, MAHLI started science operations from its vantage point at the Turret of MSL's robotic arm.

For more information on MAHLI Checkouts, visit the MSL Mission Updates Site, and for images of Curiosity and its components, visit the Sol 34 , Sol 36 and Sol 45 Galleries.

During CAP2, MAHLI was used to take a variety of images from the different positions, showing a number of Rover Components in great detail. MAHLI acquired its first image without its removable Dust Cover on Sol 33 of the landed mission showing an area of soil near the rover featuring small pebbles and a single larger rock. Several images were taken of this area, some with the dust cover and some when it was opened to show the difference in image quality - which was quite significant.

Photo: NASA/JPL/Caltech/MSSS

Sol 33 - MAHLI Dust Cover closed (left) and open (right)

Photo: NASA/JPL/Caltech/MSSS

On Sol 34, MAHLI was used to acquire a number of images showing the underside of Curiosity including its six wheels and four forward Hazard Avoidance Cameras before starting to take images of the MAHLI Calibration Target. The Calibration Target is comprised of four components, six small plates of different colors that are used for color characterization of MAHLI, a metric bar graphic for focus characterization, a stair-step pattern for depth calibration, and a penny coin that can also be used for focus characterization. This 1909 VDB Lincoln penny was donated by MAHLI Principal Investigator Ken Edgett during MSL Construction.
"Wow, seeing these images after all the tremendous hard work that has gone into making them possible is a profoundly emotional moment," said Ken Edgett.

Photo: NASA/JPL/Caltech/MSSS

"It is so exciting to see the camera returning beautiful, sharp images from Mars."
A close-up of the penny coin shows that some dust and sand particles have settled on the coin during landing. These are a great illustration of the resolution the Mars Hand Lens Imager actually has. A closer look at the subframe shows a small grain of sand right under Lincoln's ear and one under the first '9' of 1909. The particle under the ear is 200 and the other one is about 100 microns in size. The image has a resolution of 25microns/pixel.

Photo: NASA/JPL/Caltech/MSSS

The photos of the Calibration Target show that the target was coated in a thin layer of dust during the dramatic landing on Mars when Curiosity was completing the Sky Crane Phase with its Descent Stage hovering above the rover with four active Mars Landing Engines kicking up surface material. This dust coating is of some concern for color characterization with the six plates since their color is changed slightly due to the dust. This is of particular concern for the gray-scale calibration plates, but was a potential condition that was evaluated pre-flight.

Photo: NASA/JPL/Caltech/MSSS

MAHLI was also used to check out the APXS Calibration Target as well as the SAM and CheMin Inlets to verify good positioning of the robotic arm at its Teach Points.

When taking images of the CheMin inlet, MAHLI also underwent another test of its on-board image processing algorithm which was used to merge eight frames of the target that were taken with slightly different focus configurations to provide an in-focus image product. Processing images aboard the Rover reduces required downlink data volume and increases the amount of data that can be transferred to Earth each day/sol.

Finally, on Sol 37, the robotic arm was used to touch the Observation Tray of the rover with the MAHLI contact sensors in two different positions to make sure the tray can be used for contact science on scooped or drilled samples.

For detailed information about the MAHLI Instrument, visit our extensive overview.