Category Archives: Mars Rovers

A New Drilling Technique for Curiosity

Good job kudos to the Curiosity mission team for a nice work-around for the drill.

Don’t think Curiosity has been “kicking the can around” not amounting to anything, no need to fear.

Here’s a good example of what has been going on. Don’t be fooled by scale this is not a huge feature.

NASA — NASA’s Mars rover Curiosity acquired this image using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover’s robotic arm, on March 18, 2018, Sol 1996 of the Mars Science Laboratory Mission, at 19:00:00 UTC.

When this image was obtained, the focus motor count position was 13010. This number indicates the internal position of the MAHLI lens at the time the image was acquired. This count also tells whether the dust cover was open or closed. Values between 0 and 6000 mean the dust cover was closed; values between 12500 and 16000 occur when the cover is open. For close-up images, the motor count can in some cases be used to estimate the distance between the MAHLI lens and target. For example, in-focus images obtained with the dust cover open for which the lens was 2.5 cm from the target have a motor count near 15270. If the lens is 5 cm from the target, the motor count is near 14360; if 7 cm, 13980; 10 cm, 13635; 15 cm, 13325; 20 cm, 13155; 25 cm, 13050; 30 cm, 12970. These correspond to image scales, in micrometers per pixel, of about 16, 25, 32, 42, 60, 77, 95, and 113.

Most images acquired by MAHLI in daylight use the sun as an illumination source. However, in some cases, MAHLI’s two groups of white light LEDs and one group of longwave ultraviolet (UV) LEDs might be used to illuminate targets. When Curiosity acquired this image, the group 1 white light LEDs were off, the group 2 white light LEDs were off, and the ultraviolet (UV) LEDS were off.

Image Credit: NASA/JPL-Caltech/MSSS

Oppy’s Selfie

A “selfie” of the rover Opportunity on its 5000th day on Mars – taken with the Microscopic Imager!

NASA – This self-portrait of NASA’s Opportunity Mars rover shows the vehicle at a site called “Perseverance Valley” on the slopes of Endeavour Crater. It was taken with the rover’s Microscopic Imager to celebrate the 5000th Martian Day, or sol, of the rover’s mission.

The Microscopic Imager is a fixed-focus camera mounted at the end of the rover’s robotic arm. Because it was designed for close inspection of rocks, soils and other targets at a distance of around 2.7 inches (7 cm), the rover is out of focus.

The rover’s self-portrait view is made by stitching together multiple images take on Sol 5,000 and 5,006 of the mission. Wrist motions and turret rotations on the arm allowed the Microscopic Imager to acquire the mosaic’s component images. The resulting mosaic does not include the rover’s arm.

This simulation from planning software used to write commands for the rover shows the motion of the robotic arm, and an inset view of the Microscopic Imager.

Image: NASA/JPL-Caltech

Martian Sunrise by Oppy

A few days ago I mentioned that the Mars Exploration Rover Opportunity (Oppy) is reaching another milestone, that of 5000 days on Mars and still returning science. Go Oppy!!

The image above is the Sun rising on day 4,999 or 15 February, clicking the image should open a larger version in a new window.

Here’s the caption — NASA’s Mars Exploration Rover Opportunity recorded the dawn of the rover’s 4,999th Martian day, or sol, with its Panoramic Camera (Pancam) on Feb. 15, 2018, yielding this processed, approximately true-color scene.

The view looks across Endeavour Crater, which is about 14 miles (22 kilometers) in diameter, from the inner slope of the crater’s western rim. Opportunity has driven a little over 28.02 miles (45.1 kilometers) since it landed in the Meridiani Planum region of Mars in January, 2004, for what was planned as a 90-sol mission. A sol lasts about 40 minutes longer than an Earth day.

This view combines three separate Pancam exposures taken through filters centered on wavelengths of 601 microns (red), 535 microns (green) and 482 microns (blue). It was processed at Texas A&M University to correct for some of the oversaturation and glare, though it still includes some artifacts from pointing a camera with a dusty lens at the Sun. The processing includes radiometric correction, interpolation to fill in gaps in the data caused by saturation due to Sun’s brightness, and warping the red and blue images to undo the effects of time passing between each of the exposures through different filters.

Image: NASA/JPL-Caltech/Cornell/Arizona State Univ./Texas A&M

Perseverance Valley on Mars

Perseverance Valley on Mars as seen from the Mars Exploration Rover Opportunity! I can hardly believe the rover has been on Mars for a bit over 11 years landing in January 2004 and it is still delivering science. Amazing.

NASA —

This late-afternoon view from the front Hazard Avoidance Camera on NASA’s Mars Exploration Rover Opportunity shows a pattern of rock stripes on the ground, a surprise to scientists on the rover team. Approaching the 5,000th Martian day or sol, of what was planned as a 90-sol mission, Opportunity is still providing new discoveries.

This image was taken inside “Perseverance Valley,” on the inboard slope of the western rim of Endeavour Crater, on Sol 4958 (Jan. 4, 2018). Both this view and one taken the same sol by the rover’s Navigation Camera look downhill toward the northeast from about one-third of the way down the valley, which extends about the length of two football fields from the crest of the rim toward the crater floor.

The lighting, with the Sun at a low angle, emphasizes the ground texture, shaped into stripes defined by rock fragments. The stripes are aligned with the downhill direction. The rock to the upper right of the rover’s robotic arm is about 2 inches (5 centimeters) wide and about 3 feet (1 meter) from the centerline of the rover’s two front wheels.

This striped pattern resembles features seen on Earth, including on Hawaii’s Mauna Kea, that are formed by cycles of freezing and thawing of ground moistened by melting ice or snow. There, fine-grained fraction of the soil expands as it freezes, and this lifts the rock fragments up and to the sides. If such a process formed this pattern in Perseverance Valley, those conditions might have been present locally during a period within the past few million years when Mars’ spin axis was at a greater tilt than it is now, and some of the water ice now at the poles was redistributed to lower latitudes. Other hypotheses for how these features formed are also under consideration, including high-velocity slope winds.

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for NASA’s Science Mission Directorate, Washington.

For more information about Opportunity, Visit http://www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov.

Image Credit:NASA/JPL-Caltech

 

Return to Drilling?


NASA – NASA’s Curiosity Mars rover conducted a test on Oct. 17, 2017, as part of the rover team’s development of a new way to use the rover’s drill. This image from Curiosity’s front Hazard Avoidance Camera (Hazcam) shows the drill’s bit touching the ground during an assessment of measurements by a sensor on the rover’s robotic arm.

Curiosity used its drill to acquire sample material from Martian rocks 15 times from 2013 to 2016. In December 2016, the drill’s feed mechanism stopped working reliably. During the test shown in this image, the rover touched the drill bit to the ground for the first time in 10 months. The image has been adjusted to brighten shaded areas so that the bit is more evident. The date was the 1,848th Martian day, or sol, of Curiosity’s work on Mars

In drill use prior to December 2016, two contact posts — the stabilizers on either side of the bit — were placed on the target rock while the bit was in a withdrawn position. Then the motorized feed mechanism within the drill extended the bit forward, and the bit’s rotation and percussion actions penetrated the rock.

A promising alternative now under development and testing — called feed-extended drilling — uses motion of the robotic arm to directly advance the extended bit into a rock. In this image, the bit is touching the ground but the stabilizers are not. Compare that to the positioning of the stabilizers on the ground in a 2013 image of the technique used before December 2016.

In the Sol 1848 activity, Curiosity pressed the drill bit downward, and then applied smaller sideways forces while taking measurements with a force/torque sensor on the arm. The objective was to gain understanding about how readings from the sensor can be used during drilling to adjust for any sideways pressure that might risk the bit becoming stuck in a rock.

While rover-team engineers are working on an alternative drilling method, the mission continues to examine sites on Mount Sharp, Mars, with other tools.

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington. JPL designed and built the project’s Curiosity rover and the rover’s Hazcams.

Image: NASA/JPL-Caltech

 

The Landscape of Vera Rubin Ridge

A nice look at the landscape of Vera Rubin Ridge from the Curiosity rover on Mars. I was admiring the stratification. Then I noticed the scale – click the image for a larger view and see the scale on the lower right.

NASA – This view of “Vera Rubin Ridge” from the Chemistry and Camera (ChemCam) instrument on NASA’s Curiosity Mars rover shows multiple sedimentary layers and fracture-filling deposits of minerals.

Buried layers of what is now a ridge became fractured, and the fractures were filled with mineral deposits precipitated from underground fluids that moved through the fractures.

ChemCam’s telescopic Remote Micro-Imager took the 10 component images of this mosaic on July 3, 2017, during the 1,745th Martian day, or sol, of Curiosity’s work on Mars.  The camera was about 377 feet (115 meters) away from the pictured portion of the ridge.  The rover’s location at the time, shown in a Sol 1741 traverse map, was west of the place where it began its ascent up the ridge about two months later.

The scale bar at lower right indicates how wide a feature 9 inches (22.8 centimeters) in width would look in the middle portion of the scene.

ChemCam is one of 10 instruments in Curiosity’s science payload. The U.S. Department of Energy’s Los Alamos National Laboratory, in Los Alamos, New Mexico, developed ChemCam in partnership with scientists and engineers funded by the French national space agency (CNES), the University of Toulouse and the French national research agency (CNRS). More information about ChemCam is available at http://www.msl-chemcam.com/.

Credit: NASA/JPL-Caltech/CNES/CNRS/LANL/IRAP/IAS/LPGN/Tony Greicius

Vera Rubin Ridge

NASA – This view of “Vera Rubin Ridge” from the Chemistry and Camera (ChemCam) instrument on NASA’s Curiosity Mars rover shows multiple sedimentary layers and fracture-filling deposits of minerals.

Buried layers of what is now a ridge became fractured, and the fractures were filled with mineral deposits precipitated from underground fluids that moved through the fractures.

ChemCam’s telescopic Remote Micro-Imager took the 10 component images of this mosaic on July 3, 2017, during the 1,745th Martian day, or sol, of Curiosity’s work on Mars. The camera was about 377 feet (115 meters) away from the pictured portion of the ridge. The rover’s location at the time, shown in a Sol 1741 traverse map, was west of the place where it began its ascent up the ridge about two months later.

The scale bar at lower right indicates how wide a feature 9 inches (22.8 centimeters) in width would look in the middle portion of the scene.

Image: NASA/JPL-Caltech/CNES/CNRS/LANL/IRAP/IAS/LPGN

Curiosity Climbing Mt Sharp

As seen from orbit (look at the center of the image). Click for a larger view.

NASA – the feature that appears bright blue at the center of this scene is NASA’s Curiosity Mars rover on the northwestern flank of Mount Sharp, viewed by NASA’s Mars Reconnaissance Orbiter.  Curiosity is approximately 10 feet long and 9 feet wide (3.0 meters by 2.8 meters).

The view is a cutout from observation ESP_050897_1750 taken by the High Resolution Imaging Science Experiment (HiRISE) camera on the orbiter on June 5, 2017.  HiRISE has been imaging Curiosity about every three months, to monitor the surrounding features for changes such as dune migration or erosion.

When the image was taken, Curiosity was partway between its investigation of active sand dunes lower on Mount Sharp, and “Vera Rubin Ridge,” a destination uphill where the rover team intends to examine outcrops where hematite has been identified from Mars orbit.  The rover’s surroundings include tan rocks and patches of dark sand. The rover’s location that day is shown at https://mars.nasa.gov/multimedia/images/2017/curiositys-traverse-map-through-sol-1717 as the point labeled 1717. Images taken by Curiosity’s Mast Camera (Mastcam) at that location are at https://mars.nasa.gov/msl/multimedia/raw/?s=1717&camera=MAST%5F.

As in previous HiRISE color images of Curiosity since the rover was at its landing site, the rover appears bluer than it really is. HiRISE color observations are recorded in a red band, a blue-green band and an infrared band, and displayed in red, green and blue.  This helps make differences in Mars surface materials apparent, but does not show natural color as seen by the human eye.

Lower Mount Sharp was chosen as a destination for the Curiosity mission because the layers of the mountain offer exposures of rocks that record environmental conditions from different times in the early history of the Red Planet. Curiosity has found evidence for ancient wet environments that offered conditions favorable for microbial life, if Mars has ever hosted life.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project and Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington.

Image Credit: NASA/JPL-Caltech/Univ. of Arizona

Curiosity’s Traction Control

Readers who’ve been around for a while know we’ve been keeping an eye on Curiosity’s wheels; they have taken a beating traveling around on Mars.

NASA of course has been working the problem right from the beginning and they now have come up with an algorithm to help with the problem.

JPL/NASA (Andrew Good) – There are no mechanics on Mars, so the next best thing for NASA’s Curiosity rover is careful driving.

A new algorithm is helping the rover do just that. The software, referred to as traction control, adjusts the speed of Curiosity’s wheels depending on the rocks it’s climbing. After 18 months of testing at NASA’s Jet Propulsion Laboratory in Pasadena, California, the software was uploaded to the rover on Mars in March. Mars Science Laboratory’s mission management approved it for use on June 8, after extensive testing at JPL and multiple tests on Mars.

Even before 2013, when the wheels began to show signs of wear, JPL engineers had been studying how to reduce the effects of the rugged Martian surface. On level ground, all of the rover’s wheels turn at the same speed. But when a wheel goes over uneven terrain, the incline causes the wheels behind or in front of it to start slipping.

This change in traction is especially problematic when going over pointed, embedded rocks. When this happens, the wheels in front pull the trailing wheels into rocks; the wheels behind push the leading wheels into rocks.

In either case, the climbing wheel can end up experiencing higher forces, leading to cracks and punctures. The treads on each of Curiosity’s six wheels, called grousers, are designed for climbing rocks. But the spaces between them are more at risk.

“If it’s a pointed rock, it’s more likely to penetrate the skin between the wheel grousers,” said Art Rankin of JPL, the test team lead for the traction control software. “The wheel wear has been cause for concern, and although we estimate they have years of life still in them, we do want to reduce that wear whenever possible to extend the life of the wheels.”

The traction control algorithm uses real-time data to adjust each wheel’s speed, reducing pressure from the rocks. The software measures changes to the suspension system to figure out the contact points of each wheel. Then, it calculates the correct speed to avoid slippage, improving the rover’s traction.

During testing at JPL, the wheels were driven over a six-inch (15-centimeter) force torque sensor on flat terrain. Leading wheels experienced a 20 percent load reduction, while middle wheels experienced an 11 percent load reduction, Rankin said.

Traction control also addresses the problem of wheelies. Occasionally, a climbing wheel will keep rising, lifting off the actual surface of a rock until it’s free-spinning. That increases the forces on the wheels that are still in contact with terrain. When the algorithm detects a wheelie, it adjusts the speeds of the other wheels until the rising wheel is back into contact with the ground.

Rankin said that the traction control software is currently on by default, but can be turned off when needed, such as for regularly scheduled wheel imaging, when the team assesses wheel wear.

The software was developed at JPL by Jeff Biesiadecki and Olivier Toupet. JPL, a division of Caltech in Pasadena, manages the Curiosity mission for NASA.

Image: NASA