Category Archives: Mars Rovers

Curious Wheels Update


A few days ago I did a short post on the status of Curiosity’s wheels and yesterday the mission team released their assessment:

The team operating NASA’s Curiosity Mars rover uses the Mars Hand Lens Imager (MAHLI) camera on the rover’s arm to check the condition of the wheels at routine intervals. This image of Curiosity’s left-middle and left-rear wheels is part of an inspection set taken on April 18, 2016, during the 1,315th Martian day, or sol, of the rover’s work on Mars.

Holes and tears in the wheels worsened significantly during 2013 as Curiosity was crossing terrain studded with sharp rocks on its route from near its 2012 landing site to the base of Mount Sharp. Team members are keeping a close eye for when any of the zig-zag shaped treads, call grousers, begin to break. Longevity testing with identical wheels on Earth indicates that when three grousers on a given wheel have broken, that wheel has reached about 60 percent of its useful mileage. Since Curiosity’s current odometry of 7.9 miles (12.7 kilometers) is about 60 percent of the amount needed for reaching all the geological layers planned in advance as the mission’s science destinations, and no grousers have yet broken, the accumulating damage to wheels is not expected to prevent the rover from reaching those destinations on Mount Sharp.

As with other images from Curiosity’s cameras, all of the wheel-inspection exposures are available in the raw images collections at The Sol 1315 MAHLI raw images are at The rover’s location during this wheel check was on “Naukluft Plateau” on lower Mount Sharp.

Curiosity’s six aluminum wheels are about 20 inches (50 centimeters) in diameter and 16 inches (40 centimeters) wide. Each of the six wheels has its own drive motor, and the four corner wheels also have steering motors.

Image Credit: NASA/JPL-Caltech/MSSS

Curious Wheels


Curiosity took this image on 16 April 2016, Sol 1313 of the Mars Science Laboratory Mission, at 08:18:49 UTC.

We’ve been keeping an eye on the wheels for a couple of years now due to the wear they show. The MSL mission team is also keeping watch and planning some of the drives with potential for further damage in mind. It looks like their efforts are working because the damage doesn’t look any worse than it was at least from what we see here.

Image Credit: NASA/JPL-Caltech/MSSS

Martian Dust Devil


The rover Opportunity looks back at its tracks leading up the north-facing slope of “Knudsen Ridge,” which forms part of the southern edge of “Marathon Valley” and saw the very well formed dust devil.  Click the image for a larger version.

Opportunity took the image using its navigation camera (Navcam) on March 31, 2016, during the 4,332nd Sol (Martian day).

Image: NASA/JPL-Caltech


Knudsen Ridge


The Mars rover Opportunity used it’s PanCam to take this picture, actually a series of images taken on 29 and 30 October 2014 which is the 4,182nd and 4,183rd Martian day (sol) on Mars!  The view is of Knudsen Ridge on the southern edge of the Marathon Valley.

By February 2016, the rover ascended slopes of about 30 degrees onto the flank of Knudsen Ridge, headed for targets of “red zone” material to examine there.  A 30 degree slope, pretty good for the old rover.

Marathon Valley cuts generally east-west through the western rim of Endeavour Crater. The valley’s name refers to the distance Opportunity drove from its 2004 landing site to arrival at this location in 2014. The valley was a high-priority destination for the rover mission because observations from orbit detected clay minerals there.

By the way, Knudsen Ridge is an informal name chosen by the Opportunity science team to honor the memory of Danish astrophysicist and planetary scientist Jens Martin Knudsen (1930-2005), a founding member of the team.

Image: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

Selfie Time


Another of Curiosity selfie, this one combines 57 images taken by the Mars Hand Lens Imager (MAHLI) camera at the end of Curiosity’s arm on Jan. 19. The image was taken in part of the Bagnold Dune Field, which lines the northwestern flank of Mars’ Mount Sharp.

Credits: NASA/JPL-Caltech/MSSS

It’s the Summer Solstice!


On Mars that is.

This image is from the Rear Hazcam on the Mars Science Laboratory or Curiosity.  The image was taken on 03 January 2016 at 09:38:26 UTC (according to NASA).

Those light-colored (white) lines are kind of strange, probably made by the wheels of the rover.

Incidentally, the Martian Autumnal equinox occurs on 04 July 2016,  the same day as the Juno spacecraft “arrives” at Jupiter.

Image: NASA/JPL-Caltech

Under Curiosity


Here’s a look underneath the Curiosity rover on Mars.   This is a raw image so it is just as the camera saw it, meaning no processing and it hardly needs any, very nice.  The rover seems to be fairly clean considering the environment, however, looks can be very deceiving especially in that light.

The page with the image also has a very informative caption:

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 November 29, 2015, Sol 1178 of the Mars Science Laboratory Mission, at 13:49:13 UTC.

When this image was obtained, the focus motor count position was 12582. 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.

There is a large version of the image at JPL’s Mars Science Laboratory site should you want to have a nice desktop version.
Image Credit: NASA/JPL-Caltech/MSSS