Spirit Update: ‘Stub Toes’ Won’t Stop Spirit

sol 74, Mar 19, 2004

The image is the first-ever microscopic look inside a drift. It captures only the scuffed interior of the Serpent drift and is dominated by larger pea-shaped particles. These grains are not natural to the inside the drift, but are crust particles that have tumbled into the scuffed area as a result of the digging. These grains lost their dust cover in the process of falling into the scuff, giving scientists clues about the strength – or lack of strength – of the bond between the dust and sand particles.
     Most interesting to scientists are the fine grains making up the interior of Serpent drift. The grains of sand found within drifts or dunes on Earth are usually about 200 micrometers (.008 inches) in diameter — much like sand on a beach. On Earth, dunes are formed when sand particles of this size are bounced across a surface by wind and collect together as drifts. Smaller particles, like the ones making up Serpent drift, would not necessarily collect into a dune on Earth, but would more likely be distributed across the surface like dust. The fine grains making up the interior of Serpent drift are no larger than 50 or 60 micrometers (.002 inches) and can be compared to silt on Earth.
     How did this very fine material managed to accumulate into a drift? Earth-based tests that simulate the wind speed and atmospheric density of Mars have found it difficult to reproduce dunes with grain particles as small as those found in the Serpent drift. However, Earth-based tests cannot duplicate the gravity of Mars, which is one-third that of the gravity on Earth. This environmental factor is a likely contributor to the diminutive material making up Serpent drift.

USGS / Cornell / NASA/JPL

Spirit began the morning of Sol 74, which ended at 6:25 a.m. PST on March 19, 2004, by completing an alpha particle X-ray spectrometer integration on the target "Panda," inside the scuff on "Serpent" drift. Then Spirit placed the alpha particle X-ray spectrometer back down on the target "Polar" for a 30-minute integration. During that integration, Spirit took some images of disturbed soil with the panoramic camera, and acquired some ground temperatures with the miniature thermal emission spectrometer. Spirit then switched the tools on its robotic arm to the Mössbauer spectrometer for an hour-long integration on Polar. During that integration, the rover took some sky and ground measurements with the mini thermal emission spectrometer. Spirit finished its arm activities for the day by acquiring three microscopic images of Polar and three more of Panda.

Starting around 12:35 p.m. Mars Local Solar time, Spirit made a direct drive of about six meters (19.7 feet) to another section of the Serpent drift complex, called "Stub Toe." There the rover repeatedly scuffed the drift and advanced .15 meters (half a foot) in a series of five "scuff and drives." After the five scuffs and advances were made, Spirit roved forward another 3 meters (9.8 feet) and then looked back over its shoulder using the mini thermal emission spectrometer and navigation cameras to analyze the damage. The rover continued along the Bonneville crater rim with a 16-meter direct drive, and then an auto-navigation drive for 9 meters (29.5 feet). Spirit completed a final set of drives to set up for a touch and go on sol 75 at around 2:10 p.m. Mars Local Solar time. The total amount of driving for sol 74 was an impressive 34.3 meters (112.5 feet).

Spirit then took navigation camera and panoramic camera images of the drive directions for planning the sol 75 traverse. The rover acquired some mini thermal emission spectrometer reconnaissance images and then took a 30-minute siesta before the afternoon Odyssey relay pass. During that pass, Spirit used the mini thermal emission spectrometer to acquire a sky profile and ground temperature observations.

On sol 75, which will end at 7:05 a.m. PST on March 20, 2004, Spirit will place the microscopic imager on a soil target and drive about 22 meters (72.2 feet) around the Bonneville crater rim. Spirit will also conduct atmospheric observations with the mini thermal emission spectrometer and panoramic camera.

Spirit Update Archive

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Spirit Update: Steering to ‘Serpent’

sol 71, Mar 16, 2004

A drift dubbed "Serpent" stretches in front of NASA’s Mars Exploration Rover Spirit in this picture from the left eye of Spirit’s front hazard-avoidance camera. Spirit took the image during its 71st martian day, or sol, on Mars (March 15, 2004) while exploring the rim of the crater nicknamed "Bonneville." The following sol, the rover used its wheels to dig into the drift and expose material under the surface.


Spirit began sol 71, which ended at 4:26 a.m. PST March 16, 2004, with a morning nap to re-charge after the record-breaking number of activities it accomplished on sol 70. After that, it was back to work. Spirit began by retracting the alpha particle X-ray spectrometer, closing the doors, and imaging the doors with the front hazard avoidance cameras to confirm that they were closed. Spirit then proceeded to observe a soil target with the microscopic imager, and it also used the panoramic camera to observe the magnets, do a sky survey and capture a dust devil movie.

Then it was time to drive. Spirit completed a 15-meter (49.2 feet) blind drive followed by a 3-meter (9.8 feet) auto-navigation drive around the south rim of "Bonneville" crater toward a drift named "Serpent." Once there, Spirit completed post-drive science observations and a miniature thermal emission spectrometer study of the atmosphere, ground and future drive direction.

Spirit’s main objective on sol 72, which ends at 5:06 a.m. PST March 17, 2004, will be to disturb and analyze the material at Serpent. Spirit will drive over the dune and back up to an optimal observation position. It will then analyze the area with the panoramic camera and mini thermal emission spectrometer. Spirit will end the sol by driving back on top of the dune.

Spirit Update Archive

Opportunity Update: Try Again to Exit Crater

sol 56, Mar 21, 2004

NASA’s Opportunity tried driving uphill out of its landing-site crater during its 56th sol, ending at 10:05 p.m. March 21, PST, but slippage prevented success. The rover is healthy, and it later completed a turn to the right and a short drive along the crater’s inner slope. Controllers plan to send it on a different route for exiting the crater on sol 57.

Earlier on sol 56, Opportunity successfully examined a patch of soil dubbed "Brian’s Choice" with its Moessbauer spectrometer, alpha particle X-ray spectrometer and microscopic imager. Following the drive, it made observations with its navigation camera and miniature thermal emission spectrometer. Wake-up music for the sol was "Fly Like an Eagle," by the Steve Miller Band.

Opportunity Update Archive

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Opportunity Update: Finishing up at the Outcrop

sol 50, Mar 15, 2004

Dubbed "Carousel," the rock in this image was the target of the Mars Exploration Rover Opportunity science team’s outcrop "scuff test." The image on the left, taken by the rover’s navigation camera on sol 48 of the mission (March 12, 2004), shows the rock pre-scuff. On sol 51 (March 15, 2004), Opportunity slowly rotated its left front wheel on the rock, abrading it in the same way that geology students use a scratch test to determine the hardness of minerals. The image on the right, taken by the rover’s navigation camera on sol 51, shows the rock post-scuff. In this image, it is apparent that Opportunity scratched the surface of "Carousel" and deposited dirt that it was carrying in its wheel rims.

Washington University (St. Louis) / Cornell / NASA/JPL

On sol 50, which ended at 4:08 p.m. PST on March 15, Opportunity got closer to completing its observations of the rock outcrop. The rover arm, with the alpha particle X-ray spectrometer at the ready, was placed on the rock called "Shark’s Tooth" for a 30-minute observation. The microscopic imager then took a series of pictures of the targets "Enamel 1" and "Lamination." The focus then switched back to "Shark’s Tooth" for an examination by the Mössbauer spectrometer.

The song chosen to awaken Opportunity was "The Dentist" by Bill Cosby, in honor of the toothy targets in "Shark’s Cage."

The sol also included many panoramic camera observations of targets with creative names like "Patio Rug," "Anaconda Snake Den," "West Zen Garden" and "Garter Snake."

The next sol calls for a final experiment at the outcrop called "scuffing." "Scuffing" essentially turns one of the rover wheels into a tool to scrape a rock to help determine its hardness. The rock "Carousel" will be scraped by Opportunity’s front left wheel. After that experiment, the rover will begin its trans-crater traverse to five soil survey targets, the first of which will lead Opportunity up the sandy southern face of the crater.

Opportunity Update Archive