On sol 279, Spirit was parked at the location where a second occurrence of a problem with the rover's dynamic brake relay anomaly had halted a planned drive on sol 277. Scientists took the opportunity to analyze disturbed soil in front of the rover. Spirit deployed its robotic arm, acquired images of the soil with the microscopic imager, and placed the alpha particle X-ray spectrometer on a new target, named "TakeABreak," for an overnight integration.

Sols 280, 281, and 282 were built as a single three-sol plan to execute over Earth's weekend. On sol 280, Spirit acquired morning observations of sky and ground with its miniature thermal emission spectrometer, took a panoramic camera image to assess atmospheric quality, and completed the overnight alpha particle X-ray spectrometer measurement. After a midday nap, Spirit did a tool change from the alpha particle X-ray spectrometer to the Moessbauer spectrometer and began an overnight integration on the same soil patch.

On sol 281, Spirit completed the Moessbauer spectrometer measurement, took a midday nap, acquired three images of a nearby target called "Coffee" with the microscopic imager, and stowed the robotic arm. Spirit then successfully drove about 4 meters (13 feet) backwards, putting the target "Uchben" into the workspace of the robotic arm. The drive included straightening the right front and left rear steering wheels, which are the two impacted by a problem with the relay that is used in turning the steering motors on and off. The drive also successfully tested driving without use of the right front and left rear steering wheels to limit use of these motors while investigation of the malfunction continues.

On sol 282, Spirit acquired measurements of the sky and ground in the morning with the miniature thermal emission spectrometer, took the usual midday nap, and then made remote-sensing observations in the afternoon, including some navigation camera images for use in planning of future driving.

On sol 283, after receiving its daily commands and acquiring a panoramic camera assessment of atmospheric quality and miniature thermal emission spectrometer measurements of the sky and ground, Spirit took a midday nap. In the afternoon, Spirit deployed the robotic arm and acquired 20 images of a target region called "Koolik" on Uchben with the microscopic imager. Spirit then deployed the alpha particle X-ray spectrometer for an overnight integration.

On sol 284, which ended on Oct. 25, Spirit completed the alpha particle X-ray spectrometer measurement and then did a tool change to the Moessbauer spectrometer for a nighttime integration on Koolik.

Daily Update - 10/22/04
Wave Goodbye to 'Wopmay'
Opportunity Status for sol 258-264

Opportunity's health is excellent. Solar exposure continues to be very good. Opportunity spent its first night inside "Endurance Crater" on sol 134. To date, the rover has spent 130 sols in the crater, grinding 21 targets with the rock abrasion tool, performing 62 integrations with the Moessbauer spectrometer and 33 with the alpha particle X-ray spectrometer, and taking 115 observations with the miniature thermal emission spectrometer. Opportunity finally completed observations on the rock "Wopmay," and is ready to begin its trek towards "Burns Cliff" on the way to exiting Endurance Crater.

Sol details
On sol 258, Opportunity examined three targets ("Otter," "Jenny," and "Hiller") on Wopmay with its microscopic imager. Each of the observations was designed to produce a mosaic. They relied on touching the instrument's contact sensor to the uneven surface of Wopmay for each quadrant of each mosaic to ensure appropriate standoff distances for good focus.

Sols 259 through 261 were designed as a single three-sol weekend plan. During the morning of sol 259, arm operations continued with two more microscopic imager mosaics of the targets "Jet Ranger 2" and "Twin Otter." In the early afternoon, Opportunity placed its alpha particle X-ray spectrometer in a hover position approximately 1 centimeter (0.4 inches) above Otter. After a couple of naps and miniature thermal emission spectrometer observations, the rover went into deep sleep until the next morning.

The first part of a reading with the alpha particle X-ray spectrometer over Otter was performed for three hours in the morning of sol 260. During the same period, the rover made navigation camera, panoramic camera, and miniature thermal emission spectrometer cloud observations, then snapped images with the navigation and panoramic cameras in the drive direction. While performing an atmospheric observation with the panoramic camera, Opportunity collected extra images of the sky close to the Sun to allow observations of the dust accumulation on the camera's window.

In the early morning of sol 261, the reading with the alpha particle X-ray spectrometer resumed, continuing until about 11 a.m. local solar time and producing excellent spectra despite the standoff position of the sensor. Opportunity then collected Moessbauer data over Otter for another three hours. Several remote science observations were made over the course of the sol, including photometric measurements with the panoramic camera and targeted observations of Wopmay with the miniature thermal emission spectrometer and the panoramic camera observations.

On the morning of sol 262, Opportunity took a third photometric measurement and used the panoramic camera to study Wopmay, concluding the weekend plan. In the early afternoon, the rover made a final microscopic image of the target "Hercules" on Wopmay, then backed away as part of a plan to re-approach the back side of Wopmay for possible additional measurements. Navigation camera imagery of the back of Wopmay was collected in the afternoon, followed by extensive panoramic camera imaging the next morning. Unfortunately, due to slippage during the traverse, Opportunity didn't reach its desired vantage point, and the target was not in view.

For sol 263, a decision was made to delete the panoramic camera imagery without downlinking it, since on board memory was tight and we already have complete coverage of the part of Wopmay captured. The new plan was to continue the rover's drive toward the back of Wopmay, and repeat the imaging observations attempted in the sol 262 plan. But as Opportunity drove toward Wopmay, it encountered a hidden obstacle: a rock buried under the sand that resulted in 100 percent slip for a good part of the traverse. Once the rover was clear of the rock, it continued from a point much closer to Wopmay than anticipated. Rover planners estimated that, at the end of the traverse, Opportunity was within 30 centimeters (just under one foot) of Wopmay, uncomfortably close!

On sol 264, which ended on Oct 21, Opportunity backed away from Wopmay. The planned drive was 2.5 meters (8.2 feet) but the actual drive was 2.57 meters (8.4 feet). Opportunity is now in position to begin its drive toward Burns Cliff.

Total odometry after sol 264 is 1,638.57 meters (1.0181 mile).

Daily Update - 10/21/04
Welcome to 'Wopmay'
Opportunity Status for sol 251-257

Opportunity continues to be in excellent health working inside of "Endurance Crater." The current cycle is to use the deep-sleep mode every second night and to support an early morning Odyssey communications pass on the non-deep-sleep nights. Opportunity is experiencing very good solar exposure, averaging more than 700 watt-hours per sol available from the solar arrays. Driving to a rock called "Wopmay" has proven to be more challenging than expected, with Opportunity experiencing drive slippage of more than 50 percent in a couple of instances.

Sol details:
For sol 251, the plan was to put Opportunity in final position at Wopmay, a convoluted and creviced rock of great interest to the science team. After remote-sensing observations in the morning, the rover drove toward Wopmay on its own, using its visual odometry software. Unfortunately, despite the rover planners' attempt to anticipate slippage during the traverse, the direction of the slippage differed from the prior sol, leaving the rover too close to Wopmay to permit deployment of its robotic arm. Opportunity conducted afternoon remote-sensing observations, then went into deep sleep.

Sols 252 through 254 were planned as a group, due to the rover team's switch to a five-day-a-week planning schedule. On the morning of sol 252, Opportunity performed remote sensing, including two photometry survey observations, a cloud-search movie and imaging of Wopmay with the panoramic camera using 13 filters. In the afternoon, the rover backed away from the target to reach a staging position for attempting to reach the most interesting part of Wopmay, the upper right lobe, on a drive after the rover team's weekend. Deep sleep was disabled, allowing Opportunity to support a Mars Odyssey pass in the early morning of sol 253.

Sols 253 and 254 were remote-sensing sols. On sol 253, the rover imaged its filter magnets and performed multiple observations with its miniature thermal emission spectrometer. Before the rover shut down for the night, it positioned the spectrometer for a middle-of-the-night observation. Opportunity woke up first at 10 p.m. local solar time to begin heating, then again at 11 p.m. for the actual observation, then slept until about 7 a.m. local solar time on sol 254. Upon waking, the rover began another day of remote science, including multiple observations of sky and ground with its miniature thermal emission spectrometer.

During planning for sol 255 it was decided that approaching Wopmay from directly uphill would be too risky due to concerns about vehicle stability, so the plan was revised to approach Wopmay very slowly from an angle and not to deploy the robotic arm with any pre-loading on the rock. This would minimize chances of the vehicle slipping or placing undue stress on the arm. So the plan for sol 255 was to back up the hill, away from Wopmay, and position Opportunity to begin the slow angular, downhill approach to Wopmay. The drive successfully covered 7.8 meters (about 26 feet), leaving Wopmay 3.4 meters (11 feet) away. Opportunity also performed about an hour of remote science observations before entering deep sleep for the night.

On sol 256 Opportunity continued its slow approach toward Wopmay. After receiving its morning uplink, Opportunity performed twenty minutes of panoramic camera observations, then crawled forward just over 2 meters (about 7 feet), taking three small steps and performing a turn in place. During these moves Opportunity experienced slippage as high as 54 percent. By the end of the drive, Wopmay was approximately 1.5 meters (about 5 feet) away. Opportunity performed another hour of post-drive remote science observations, took a nap, then used an afternoon communication session and early morning communications with Odyssey.

Sol 257, which ended on Oct. 14, was a final approach sol. During the morning Opportunity extended its arm to use its microscopic imager for an hour on soil targets just in front of Wopmay. The rover then stowed its arm and began the final approach toward Wopmay. The drive was commanded for rolling 30 centimeters (about 1 foot) with the expectation of approximately 50-percent slippage. The expected traverse was 45 centimeters (about 1.5 feet). The last few drives taxed the rover planners and they really came through! Opportunity is perfectly positioned to examine Wopmay with the rover's microscopic imager and alpha particle X-ray spectrometer.

Total odometry after sol 257 is 1,630.00 meters (1.0128 mile)!

Daily Update - 10/20/04
Spirit Investigating Ancient Rocks
Spirit Status for sol 272-278

Spirit had a productive week investigating the rock "Tetl." On sol 277, Spirit attempted a drive to the next rock target, "Uchben," which means "ancient" in the old Mayan language. Halfway into that drive, Spirit experienced a repeat problem in the steering motor control system that engineers first saw on sol 265. Engineers repeated diagnostic tests for the problem on sol 278. Those tests showed that the electronics relay in question is still functional, but appears to operate intermittently. Spirit is otherwise healthy and is in a safe location.

On sol 272, Spirit took images with the microscopic imager to create a mosaic of Tetl's layered rock face.

On sol 273, Spirit captured more microscopic images of Tetl's layered face, then put the alpha particle X-ray spectrometer in place for an early morning observation.

On sol 274, Spirit woke up at 4:00 a.m. to start the alpha particle X-ray spectrometer observation. The alpha particle X-ray spectrometer stayed on until the start of normal morning atmospheric science observations. Spirit also used its miniature thermal emission spectrometer to observe nearby rocks named "Zackuk" and "Palenque," which are possible future targets for in-depth observations. Later, Spirit changed tools on its robotic arm, placing the Moessbauer instrument on Tetl for an observation the next morning.

On sol 275, Spirit completed a 6-hour Moessbauer integration and performed daily atmospheric observations. This was the final sol of Spirit's weekend plan and was purposely simple to enable the sequencing team to complete a 3-day plan on Friday.

On sol 276, Spirit restarted the Moessbauer instrument at 4:00 a.m. for another 10 hours of integration time on the same spot. Spirit also took a few final microscopic images of Tetl, then stowed the robotic arm in preparation for the next sol's drive.

On sols 277 and 278, Spirit attempted a drive to Uchben, another layered rock roughly 6 meters (20 feet) northeast of Tetl. About 2.5 meters (8 feet) into the drive, the mobility software attempted to move a steering motor by first commanding open a relay (electronic switch) that releases a dynamic brake. The feedback from that command indicated that the relay was still closed, so the motor control software declared an error. Due to the error, the rover ignored that steering command and all subsequent driving commands. The root cause of the failed relay command is under investigation. A diagnostic test last run on sol 270 was repeated on sol 278, which ended on Oct. 14. That test showed that the steering motor's dynamic brake relay can still be opened and closed, but does occasionally (5 out of 10 times) indicate that it is still closed after being commanded open.

More diagnostics tests are needed before the source of the problem can be positively identified. Until then, engineers will continue to drive, but will steer the rover in a tank-like fashion, not using the steering actuator in question.

Future plans are to clear the drive error and attempt another drive to Uchben on sol 281. Engineers are also planning to run more diagnostic tests starting on sol 282.

Daily Update - 10/13/04
Working towards 'Wopmay'
Opportunity Status for sol 245-250

Opportunity is in excellent health. The current pattern is to use the deep-sleep mode every second night, and to support an early morning Odyssey communications pass on the non-deep-sleep nights. Opportunity is experiencing good solar exposure, averaging more than 660 watt-hours per sol from the solar arrays. The rover is poised for final approach to "Wopmay," a fascinating creviced rock with a brain-like appearance.

Sol details:
Sol 245 was a restricted sol. Opportunity could perform only remote sensing. The rover took images in all directions with its navigation camera. It used its miniature thermal emission spectrometer for sky and ground observations. Then it went into deep sleep for the night of sol 245 into the morning of sol 246.

Sols 246 through 248 were planned in a single planning cycle as part of our 5-day-a-week schedule. The uplink team accomplished a Herculean task, successfully completing and uplinking three science-intensive sol plans despite some issues encountered during the day.

Opportunity began sol 246 by placing the Moessbauer spectrometer and starting a long reading with it on a target called "Void." While collecting the Moessbauer data, Opportunity also performed two hours of observations with its panoramic camera and its miniature thermal emission spectrometer. The Moessbauer integration was paused just before the afternoon communication session with Mars Odyssey. Deep sleep was disabled so that Opportunity could support an early morning communications session on sol 247 and restart the Moessbauer integration.

Sol 247 was day two of the long Moessbauer integration; the integration ran throughout the sol until early evening, at which time Opportunity again paused and entered deep sleep overnight. During the day, Opportunity also completed a series photometric observations with its panoramic camera.

On sol 248 Opportunity exited deep sleep and restarted the Moessbauer integration. During pre-uplink science activities in the early morning, the rover completed a sky observation pattern that planners call an itty-bitty cloud movie. In the martian afternoon, Opportunity ended the long Moessbauer integration and turned the tool turret on its arm to place the alpha particle X-ray spectrometer on Void. The X-ray instrument did not start taking data until early the next morning. Opportunity did not go into deep sleep overnight. Instead, it used an early morning Odyssey communications session and immediately afterwards started the alpha particle X-ray spectrometer integration.

Opportunity completed the alpha particle X-ray spectrometer integration on the morning of sol 249. The rover then performed a series of microscopic imaging activities, stowed the instrument deployment device and began driving toward its next target, Wopmay. The 19.98-meter (about 66-foot) drive went well, but with more slippage than expected. At the end of the drive, the nearest visible face of Wopmay was only 2 meters (about 7 feet) from the center of the rover; far enough not to have been a hazard during the drive, but closer than was predicted. Slip estimates indicate radial slippage as high as 64 percent. Opportunity used deep sleep overnight on sol 249.

On sol 250, which ended on Oct. 7, Opportunity performed the first part of a planned two-sol approach to Wopmay. This nearly 7-meter (23-foot) drive went well. The end of the drive incorporated conditional arcs to be executed only if the rover was in the appropriate position. The drive put the rover in very good position for the final approach on sol 251.

Total odometry after sol 250 puts Opportunity just over the one-mile mark: 1,611.99 meters (1.0016 mile)!

Daily Update - 10/11/04
Spirit investigating 'Tetl.'
Spirit Status for sol 263-271

After working on Mars for three times as long as its primary three-month mission, Spirit is healthy and currently investigating the rock called "Tetl" in the "Columbia Hills." In the language of the ancient Mayans, tetl means stone.

On sol 263, Spirit successfully drove approximately 7 meters (23 feet) and acquired images to build a digital elevation map of the hills. This put Spirit on the south side of a 2-meter-diameter (7-foot-diameter) depression, with Tetl on the opposite side.

On sol 264, Spirit drove about 4 meters (13 feet) around the edge of the depression to keep the rover's solar panels (which are the rover's main power source) tilted toward the Sun. Since the Sun moves low across the northern sky over Gusev Crater at this time of year, rover planners are attempting to keep the solar panels tilted toward the north. The drive included use of the five-wheel mode to minimize use of the sticky right front wheel, which inefficiently pulls too much power when it is activated. Spirit also gathered additional about potential science targets, using the miniature thermal emission spectrometer and panoramic camera at the end of the rover's robotic arm.

On sol 265, Spirit attempted to approach Tetl, but the drive ended early because the flight software detected that a steering brake control function did not work. Remote sensing data was still acquired.

On sol 266, with an ongoing investigation of the steering anomaly, no further driving was planned. Several targets in front of the rover were selected for the alpha particle X-ray spectrometer and Moessbauer spectrometer. Spirit completed alpha particle X-ray spectrometer readings on two different locations.

On sol 267, Spirit successfully acquired remote sensing data and moved its robotic arm to put the alpha particle X-ray spectrometer at a third position during the day and a fourth position overnight.

On sol 268, Spirit acquired additional remote sensing data and performed a tool change to the Moessbauer spectrometer, then started an overnight integration with that instrument.

On sol 269, Spirit continued the Moessbauer spectrometer integration and performed a diagnostic test on the steering brake. The test indicated that there was no problem with the commanding process at that time.

On sol 270, Spirit acquired remote sensing data, stowed its arm, and ran another steering diagnostic test. The cause of the steering brake issue has not been identified, but tests indicate that electronics related to the brake function and the overall steering capabilities of Spirit are healthy. Engineers are proceeding with normal operations, including mobility.

On sol 271, which ended on Oct. 7, Pacific Time, Spirit successfully drove approximately 2 meters (6.6 feet). This put Tetl within reach of the robotic arm. After the drive, Spirit used its navigation camera to view the scene from the rover's new location.

Spirit has driven a total of 3,641 meters (about 2.3 miles) since landing nine months ago.

Future plans for Spirit include more intense investigations of Tetl and a 20-meter (66-foot) drive to a target called "Machu Picchu."