Sol-by-sol summaries:
Sol 353 was a restricted sol. (Results of 352 drive were not known by the planning team in time to calculate the final heat shield approach). Opportunity performed over two hours of observations using the panoramic camera and miniature thermal emission spectrometer.

On sol 354, Opportunity performed 10 minutes of pre-drive remote-sensing observations, then moved forward to get in final position for extending its instrument deployment device (robotic arm) to the heat shield. A drive of 0.7 meter (2.3 feet) was successful, placing the heat shield in reach of the arm. Opportunity performed more than an hour of post-drive imaging.

Sol 355 was a restricted sol. Opportunity performed over two hours of remote sensing.

Sols 356 and 357 were planned in a single planning cycle. On sol 356, Opportunity used the microscopic imager to examine the heat shield. Using the arm to position the microscopic imager, Opportunity spent 90 minutes collecting high-resolution images of the heat shield. On sol 357, the rover performed thermal inertia measurements throughout the sol. Using the miniature thermal emission spectrometer to image the same target at different times, Opportunity took measurements as late as 23:00 Mars local solar time.

On sol 358, Opportunity retook some microscopic images of the heat shield with the dust cover open. The rover then stowed its arm and began its drive south, away from the heat shield. Opportunity is now headed for a small crater called Argo, which is approximately 300 meters (about 984 feet) away. Opportunity successfully covered 86.3 meters (283 feet) on this sol.

Sol 359, which ended on Jan. 27, was another restricted sol. The rover was sent commands for over 2.5 hours of remote sensing.

Total odometry as of sol 358 is 2,200.6 meters (1.37 miles).

Daily Update - 1/24/05
Spirit at 'Peace'
Spirit Status for sol 367-373

Spirit is healthy, but reduced sunlight has been reaching the rover through the atmosphere due to a possible dust storm identified from orbital data. Despite limited energy during the period from sol 367 through sol 373, Spirit made good progress by driving about 20 meters (66 feet) closer to top of "Cumberland Ridge." Spirit is investigating a rock called "Peace."

Sol-by-sol summaries:
During a two-sol plan on sols 367 and 368, Spirit traversed about 14 meters (46 feet) up the steep hillside toward the ridge and a target named "Larry's Lookout." The average slippage during the drive is estimated at 14 percent, indicating much firmer footing than previous drives. Sol 368 was a remote sensing sol. Spirit made observations with its panoramic camera and its miniature thermal emission spectrometer and performed a successful test of the right eye of the panoramic camera to find the Sun. The rover team usually uses the left panoramic camera to locate the Sun.

"Sun finding" is sometimes called "get fine attitude" or "attitude update," and is something engineers do every couple of weeks to correct error in the rover's knowledge of attitude -- mostly which way is north. This takes the same kind of images of the Sun that the atmospheric science team does, but the engineers use the data to determine attitude. Between the updates, the rover uses the onboard computer to keep track of attitude changes, but error builds up in this measurement over time. In general, most of the panoramic camera images of the Sun are acquired for atmospheric science. Many images are used to determine how much dust is in the atmosphere (atmospheric opacity or Tau). Usually engineers take these images three or four times during the day. With the current dust storms, the team is taking even more images of the Sun.

Sols 369, 370, and 371 were part of a three-sol plan. On sols 369 and 370, Spirit looked for more science targets en route to Larry's Lookout. On sol 371, Spirit completed a 6-meter (20-foot) drive to arrive at the rock target "Peace." Due to the slope and small rocks in area, Spirit sat at an overall tilt of 19 degrees to the north-northeast, which was very good for maximizing solar energy.

On sol 372, Spirit deployed the rover arm and acquired a set of images of Peace taken by the microscopic imager. A sequencing error prevented the alpha particle X-ray spectrometer from being placed on the rock, delaying the planned integration. The opacity of the sky, or Tau, which is the amount of light that cannot penetrate through the atmosphere, rose sharply from 0.8 to 1.1.

On sol 373, Spirit acquired more images with the microscopic imager and brushed Peace with the rock abrasion tool. The rover then placed the alpha particle X-ray spectrometer on Peace successfully for a nighttime integration. Tau continued upwards to 1.3, further reducing solar energy for Spirit.

Solar energy continues to be a precious resource because of the high Tau on sol 373. Although dust storms are more likely at this time of martian year, the start of the true dust storm season is still months away. Sol 373 ended on Jan. 20, 2005.

Daily Update - 1/24/05
Opportunity Checks Out the First Meteorite Found on Another Planet!
Opportunity Status for sol 347-352

Opportunity completed its work on "Heat Shield Rock" during sols 347 through 352, then got into position for more observations of the heat shield. This rock is now known to be an iron-rich meteorite, thanks to findings of the alpha particle X-ray spectrometer, Moessbauer spectrometer and the miniature thermal emission spectrometer. The rover remains in good health.

The team continues to closely monitor orbital images for signs of dust storms. Tau, a measure of the sky opacity, has hovered in the 0.8 to 0.9 range for the past week; tau was roughly 0.5 before recent dust disturbances in the region.

Since sol 331, a mottled pattern has been seen on sky portions of images from the rear hazard avoidance camera. The pattern was originally thought to be a sky pattern caused by the dust storm occurring at that time. After a closer look at the mottled pattern in subsequent images, it appears that there is actually a deposit of some sort on the rear hazard avoidance camera lenses. The deposit may be storm dust that blew in their direction. It might also be fine dust from the heat shield debris that blew onto them or was kicked up by Opportunity's wheels as it drove around the debris site. The team decided to go ahead with a final close-up imaging campaign of the heat shield despite the risk of further deposition on the camera lenses because of the rare opportunity to examine a spent heat shield on Mars. Rover drivers are taking extra precautions to drive around debris and to find safe orientations for the rover as it works. The team has decided to forgo observations at the heat shield divot due to the possibility of further contamination at that site.

Sol-by-sol summaries:
On sol 347, Opportunity unstowed its instrument deployment device (robotic arm) to take microscopic images of Heat Shield Rock, and then placed the Moessbauer spectrometer instrument on the rock for a 19-hour observation. Moessbauer integration times are longer now because the Moessbauer source has weakened as expected since landing.

On sol 348, the rover placed the alpha particle X-ray spectrometer instrument on Heat Shield Rock during the afternoon for an overnight observation. That instrument provides best results when it is cold.

On sol 349, the rover brushed an area on Heat Shield Rock using the rock abrasion tool, took microscopic images of the brushed spot, then placed the alpha particle X-ray spectrometer on the spot for another overnight observation.

350 - Opportunity changed tools on the arm to the Moessbauer instrument for another long observation on the brushed area.

351 - The rover changed tools on the arm back to the alpha particle X-ray spectrometer instrument again, putting it in place for another overnight observation of Heat Shield Rock.

352 - Opportunity took some final microscopic images of the rock then backed away for observations with the panoramic camera and miniature thermal emission spectrometer. The rover then drove to within about 1 meter (about 3.3 feet) of the largest piece of the heat shield in preparation for more observations of spent heat shield material with the microscopic imager.

Daily Update - 1/14/05
Spirit Close to the Crest
Spirit Status for sol 360-366

Currently Spirit is approximately 50 meters (164 feet) from a target called "Larry's Lookout" on a ridge line in the "Columbia Hills." During the period from sol 360 through sol 366, engineers focused on maximizing the amount of time Spirit could drive every sol with limited power. The driving is slow and difficult; Spirit is encountering many rock obstacles and patches of soft sand that are causing Spirit to either slip or dig in. Just when it looked like Spirit might not be able to reach Larry's Lookout, the rover had three successful drive sols. Spirit is in excellent health as the team looks forward to celebrating the anniversary of Opportunity's landing on Jan. 24.

Sol-by-sol summaries:
Sol 360 was a repeat of sol 358's drive. Spirit performed an "S" turn and then drove straight for about 4 additional meters (13 feet). This was a refreshingly good result for the tough terrain where Spirit was located. Spirit experienced as much as 48 percent slippage during the drive, but ended up moving a total distance of 9.7 meters (31.8 feet). Spirit also performed 20 minutes of post-drive imaging.

Sol 361 was a restricted sol due to a late downlink of data needed for more extensive planning. That ruled out any driving or use of the instrument deployment device. Spirit completed almost 2 hours of remote sensing observations using the panoramic camera and miniature thermal emission spectrometer.

Sol 362 and 363 were planned in a single planning cycle. Sol 362 was another remote sensing sol. On sol 363, Spirit attempted a 10-meter (33-foot) drive. Spirit accomplished about 3 meters (10 feet) of the drive before stopping due to high wheel slippage. Spirit experienced slippage of up to 98 percent on portions of this drive. Spirit then performed 20 minutes of imaging.

On Sol 364, the rover planners devised a strategy that would attempt to recover when Spirit experienced slippage of greater than 60 percent. The drive sequence was complex and Spirit's planning team had a tight planning cycle, so engineers came painfully close to missing the uplink window. The payoff for the long day was a very good drive. Spirit accomplished 7 meters (23 feet).

Spirit performed another uphill drive on sol 365. The rover drove 9 meters (29 feet) and performed 20 minutes of post-drive imaging.

The plan on sol 366 was to continue the uphill drive toward Larry's Lookout, employing all the latest rover tricks. The drive was successful as Spirit traversed more than 12 meters (39 feet) with slip averaging less than 15 degrees. Spirit performed 30 minutes of post-drive observations. Sol 366 ended on Jan. 12.

Total odometry after sol 366 is 4,030 meters (2.5 miles).

Daily Update - 1/14/05
Hovering Near Heat Shield and a Holey Rock
Opportunity Status for sol 314-346

Opportunity is healthy. It acquired microscopic images of the fractured edge of the heat-shield wreckage and began a detailed investigation of an intriguing, pitted rock a few meters to the north, called "Heat Shield Rock." The team continues to closely monitor orbital images for dust storms. The opacity of the atmosphere above Opportunity has averaged 0.75 with a slight downward (clearing) trend over the past week.

Sol-by-sol summaries:
Sols 341 through 343 were combined in a three-sol plan for the Earth weekend. On sol 341, Opportunity used a morning Mars Odyssey pass for a communications relay at about 4 a.m. local solar time and then slept until solar-array wakeup at about 8:45 a.m. After another short nap, the rover did a bit of remote sensing and received its new commands for the sol. Opportunity deployed its robotic arm and acquired 96 microscopic images of the fractured edge of the heat shield. In the afternoon it used its Moessbauer spectrometer to analyze dust on the science filter magnet. It used the deep-sleep mode overnight. On sol 342, Opportunity woke from deep sleep at about 7 a.m. local solar time and restarted the Moessbauer integration on the magnet. It was a light day of activity with afternoon remote sensing, an evening Odyssey relay pass, and then deep-sleeping overnight. On sol 343, the rover restarted Moessbauer integration on the magnet and completed afternoon remote sensing before deep-sleeping.

On sol 344, Opportunity stowed its instrument deployment device (robotic arm) and backed up about 4 meters (13 feet) before acquiring a panorama of the heat shield and other remote sensing. The rover did not deep-sleep overnight in order utilize the morning Odyssey relay and return as much data as possible. The flash memory is relatively full.

On sol 345, Opportunity acquired additional navigation-camera images of the heat shield to support a future re-approach for additional microscopic imaging. It then turned and drove north toward "Heat Shield Rock," which has pits in its surface. The rover traversed about 10 meters (33 feet) and arrived at the desired 1-meter (about 3.3 feet) standoff distance to acquire remote sensing of the rock. Opportunity used the energy-conserving deep-sleep mode overnight.

Sol 346 - Opportunity acquired additional remote sensing and then bumped forward, putting the rock within the work volume of the tools on the instrument deployment device. The rover took advantage of an early-morning communications pass, so it did not deep-sleep overnight.

Daily Update - 1/13/05
More Heat Shield Observations
Opportunity Status for sol 333-340

The week saw Earthlings celebrate a new year and Spirit's first birthday on Mars (one Earth year) while Opportunity continued its trek around its own heat shield. On Earth, the operations team experienced a few tool problems, but the support team was in position to fix most problems as soon as they were discovered.

A dust storm that affected Opportunity the previous week has slowly receded, allowing increasing solar exposure. To conserve energy, Opportunity has been going into the deep-sleep mode every night, but as power continues to improve, the team is planning to resume using some early-morning Mars Odyssey communication passes to reduce a backlog of unsent telemetry.

Opportunity continues to be in excellent health as the rover team looks forward to the Jan. 24 anniversary of Opportunity's landing.

Sol-by-sol summaries:
Sol 333 was the second sol of a two-sol plan. The day was spent monitoring the opacity of the atmosphere and performing almost three hours of remote sensing. Atmospheric opacity peaked on sol 321 at 1.25. On sol 333 it was down to 0.97 and decreasing, indicating that the sky was clearing. The amount of power generated by Opportunity's solar panels increased from 546 watt-hours on sol 321 to 630 watt-hours on sol 333.

Sols 334, 335 and 336 were planned in a single planning cycle.

On Sol 334 (New Year's Eve), Opportunity performed 90 minutes of remote-sensing observations, inspected debris from the heat shield's flank with the microscopic imager, and then placed the alpha particle X-ray spectrometer on the capture magnet on the rover's solar panel.

On New Year's Day, sol 335, Opportunity started taking data with the alpha particle X-ray spectrometer early in the morning, napped several hours, awoke and turned off that spectrometer, performed another hour of remote sensing, and then went to sleep for the night.

On sol 336, Opportunity collected another two hours of alpha particle X-ray spectrometer data on the capture magnet and made remote-sensing observations for an hour.

On the morning of sol 337, Opportunity examined the flank portion of the heat shield wreckage with the microscopic imager, imaged the capture magnet, then stowed the arm and began its drive for the day. Opportunity banked up 2 meters (about 6.6 feet), turned and drove 10 meters (33 feet) to "East Point." At East Point, Opportunity performed 30 minutes of imaging, capturing a stereo image of the heat shield and a 360-degree view with the navigation camera. The rover then drove another 12.5 meters (41 feet) to a standoff point facing the heat shield seal.

The team experienced a problem with onboard file deletion on sol 337. There was a bad parameter in one command, so Opportunity rejected the entire set of commands. The result of rejecting the command file was that Opportunity's flash memory filled up and the flight software began deleting lowest-priority data products. Approximately 150 megabits of stored data products were lost. Because many images were being acquired and processed at the same time auto-deleting was taking place, the rover's computer was running very slowly. When Opportunity attempted to perform a "Get Fine Attitude," (a command that updates the rover's knowledge of its tilt and orientation), it timed out. The rover monitors itself and cancels things that take longer than planned, the same way home computers cancel attempts to access the internet if the server doesn't respond within a certain time. Due to the time-out, Opportunity responded that it didn't know its exact attitude (setting the surface attitude pointing and positioning -- SAPP -- knowledge to "unknown"). As a result of this, subsequent commands for using the miniature thermal mission spectrometer images were rejected. Pointing the spectrometer at the Sun would severely damage it, so in order for the rover to point the instrument, it must know its attitude.

Sol 338 became a restricted-operations sol due to a long latency in receiving relayed data. Telemetry was delayed more than seven hours, so Opportunity spent the sol performing more than four hours of remote sensing. The operations team was able to react to the failed Get Fine Attitude on sol 337 by creating a real-time command to reset the surface attitude pointing and positioning knowledge. The command was sent as part of the sol 338 uplink and worked as planned. Opportunity also performed both a left-eye and right-eye Get Fine Attitude.

Sol 339 was another "image, drive, image, drive" sol. Opportunity performed 30 minutes of pre-drive imaging, drove about 10 meters (33 feet), performed 80 minutes of mid-drive imaging, drove another 13 meters (about 43 feet) toward the charred side of the heat shield, and performed 30 minutes of post-drive imaging. All operations worked as planned, leaving Opportunity in position to approach the heat shield to perform microscopic imaging over the weekend. Sol 339 ended on Jan. 6.

Total odometry after sol 339 is 2075.52 meters (nearly 1.29 miles).

Atmospheric opacity on sol 339 was 0.83; solar array energy was 836 watt-hours.

Daily Update - 1/12/05
Spirit Continues Climbing 'Husband Hill'
Spirit Status for sol 353-359

With one eye on the weather, Spirit continued work on "Husband Hill," making detailed observations of a rock called "Champagne," using the full suite of instruments.

Engineers continue to have difficulty getting the rover to make significant progress toward a ridgeline destination due to high slippage that Spirit experiences on the sandy, sloped terrain. Spirit has been in roughly the same spot for the past 30 sols. Since temporarily getting a potato-sized rock caught in the right rear wheel on sol 339, engineers have been careful to monitor the slip as Spirit drives. If the wheels slip too much, engineers stop the drive to avoid the possibility of picking up another rock as Spirit spins and digs with its wheels.

The opacity of the sky -- or how much light does not shine through the atmosphere -- has been higher than normal in the past week due to local dust disturbances. Higher opacity means less energy for the solar-powered rover. However, despite the recent increase in opacity, Spirit has had adequate energy (with a safe margin) to continue normal operations.

The rover's power bus return is a collection of wires designed to carry current back to the rover power source (battery or solar array). Electrical current between Spirit's chassis and the power bus return changed on sol 342 from zero volts to 0.1 volts. The small change in voltage coincided with powering of heater circuits on the instrument deployment device (or rover arm). This confirms that there is a short (unexpected metal-to-metal contact) between the power bus return and the chassis, as had been suspected since October. The short is somewhere on the return side of the rover arm heater circuits. The presence of this short does not affect daily operations. It does, however, take away one layer of protection should Spirit have a short to the chassis somewhere else on Spirit.

Sol Summaries:
On sol 353, Spirit continued inspecting the rock "Champagne" and performed a Moessbauer spectrometer integration on two Champagne targets.

On sol 354, Spirit used its rock abrasion tool to brush the dust off a target on Champagne, then used the microscopic imager and the alpha particle X-ray spectrometer to analyze the dust-free spot.

On sol 355, Spirit used the rock abrasion tool to grind into Champagne, then placed the alpha particle X-ray spectrometer in the hole for an overnight observation.

On sol 356, Spirit continued using its alpha particle X-ray spectrometer on the hole drilled by the rock abrasion tool hole.

On sol 357, Spirit changed tools to the Moessbauer spectrometer and placed it in the rock abrasion tool hole for a long integration.

On sol 358, Spirit took microscopic images of the rock abrasion tool hole, then stowed the rover arm. Engineers then attempted a short drive that would have allowed Spirit to image the rock abrasion tool hole from a distance. The drive did not reach the intended position because of slippage.

Sol 359 was a "restricted" sol, meaning that engineers had to plan this sol without knowing the results of the sol 358 sequence. Consequently, it was a relatively simple day that included routine atmospheric science and miniature thermal emission spectrometer observations. Sol 359 ended on Jan. 6.

Daily Update - 1/6/05
Spirit Celebrates Year Anniversary on Mars
Spirit Status for sol 346-352

Spirit landed on Mars one year ago on Jan. 3, 2004, (Pacific Time) and is still healthy and going strong!

On sol 346, Spirit confirmed that it had dumped a potato-shaped rock that had been plaguing Spirit's right rear wheel. Confirmation came by comparison of before and after images from the rear hazard-avoidance camera. The total distance driven on sol 346 was 0.33 meters (1.08 feet).

On sol 347, Spirit observed selected targets with its panoramic camera and miniature thermal emission spectrometer.

On sol 348 took pictures of a target called "Dreaming" with the microscopic imager, and then did a tool change to the alpha particle X-ray spectrometer. Spirit also made some remote-sensing observations of targets with holiday theme names.

On sol 349, Spirit did a tool change to the Moessbauer spectrometer and made more observations.

On sol 350, the plan was to drive Spirit 5 meters (16 feet) towards the rock named "La Brea." However, the drive achieved less than a meter (3 feet) due to slippage.

On sol 351, Spirit attempted to drive again. This drive involved a series of rearward and forward arcs to get to more favorable terrain. Most of the slip occurred during the forward arcs. The estimated slip on the rearward arcs was 15 per cent, but the estimated slip on the forward arcs was 39 per cent. The destination, a rock called "Dick Clark," was still about 4.2 meters away (14 feet).

On sol 352, the incomplete drive on the previous sol had left the rover team with a rock of interest right between the rover's front wheels. Spirit examined a target called "Bubbles" with its microscopic imager, then changed tools to the alpha particle X-ray spectrometer. Spirit also made sky observations with its thermal emission spectrometer and panoramic camera. Sol 352 ended on Dec. 29.

Daily Update - 1/4/05
Sizing Up the Heat Shield
Opportunity Status for sol 325-332

Opportunity is healthy and has reached the site where its heat shield hit the ground. The rover will make detailed observations of the heat shield's remains, weather permitting. The rover experienced its first dust storm since landing, which has affected the amount of energy Opportunity gets each sol. When the rover landed nearly one Earth year ago, a dust storm was subsiding and the atmosphere had an opacity of 0.9 (the higher the number, the murkier the skies). Since then, the opacity had improved significantly and was roughly 0.5 on sol 327. On sol 328 the opacity jumped to 0.6 then to 0.8, 1.2, and 1.25 on sols 329-331. As of sol 332 it is at 1.2 and dropping. Images from Mars Global Surveyor orbiter have confirmed the presence of a few small dust storms in the region. The energy intake has decreased roughly 30 percent, leaving Opportunity with less energy for operations and communications but still enough, with comfortable margin, to continue with the plan to investigate the heat shield remains. The dust storms will be monitored carefully using the rover's own instruments and images from Mars Global Surveyor. The team will also be walking through low-energy contingencies should they become necessary.

Sol-by-sol summaries:
On sol 325, Opportunity drove 27 meters (about 89 feet) backward, to "West Point." It imaged the heat shield debris field from that vantage point. The engineers choose to occasionally drive the rover backward for convenience and to keep the wheel-motor lubrication more evenly distributed.

Sol 326 was the second sol of a two-sol plan. This sol was spent imaging the heat shield debris field.

On sols 327 to 329, the Moessbauer spectrometer was placed on the compositional calibration target for a series of observations over the Earth weekend. This is done periodically to calibrate the Moessbauer instrument. The rover continued routine atmospheric observations and remote sensing of the heat shield debris field.

On sol 330, Opportunity used its panoramic camera to take images of the heat shield debris field, then drove 15 meters (about 49 feet) to a location called "South Point" for another look at the debris field.

On sol 331, Opportunity drove roughly 10 meters (33 feet) to approach the flank portion of the heat shield remains. The heat shield broke into two main piece when it hit the ground. The flank is the smaller of those portions.

On sol 332, which ended on Dec. 30, the rover made its final approach to the flank portion of the heat shield wreckage in preparation for close-up inspection of the heat shield material over the New Year's holiday weekend. The drive brought Opportunity's odometer total to 2,051 meters (1.27 miles).

Daily Update - 1/3/05
Heading for the Heat Shield
Opportunity Status for sol 320-324

As of sol 324 (Dec. 21), a healthy Opportunity has driven to within about 30 meters (about 98 feet) from the remains of the heat shield that hit the ground about 250 meters (820 feet) south of "Endurance Crater." Ending this year exploring part of the rover's entry system is a great reminder of the tremendous year Opportunity and Spirit have had thanks to the dedication and hard work of so many.

Sol-by-sol summaries:
On sol 320, Opportunity completed a variety of observations including imaging toward the heat shield. It then went into deep sleep overnight.

Sols 321, 322 and 323 were combined in a single activity plan for the Earth weekend. On the first sol of the three-sol plan, Opportunity looked at the front edge of its solar array with its microscopic imager to assess dust accumulation there. It then drove nearly 60 meters (about 197 feet) south toward the heat shield and acquired post-drive imagery to support planning of the next drive. Opportunity did not deep-sleep overnight so it could wake up to take advantage of a Mars Odyssey communications pass to return data during the night. On sol 322, Opportunity made some observations and then went into deep sleep overnight. On sol 323 it made more observations and did not deep-sleep overnight.

On sol 324, Opportunity drove nearly 90 meters (about 295 feet), bringing it within 30 meters (98 feet) of the heat shield. This was a record length for a drive that did not use the rover's auto-navigation software. It was enabled by the team's ability to identify a hazard-free route in images that the navigation camera and panoramic camera had taken of the flat terrain to be covered in the drive. The rover also made use of low-level hazard-detection software that reads rocker-bogie ("rover leg") position and rover tilt to halt a drive if the rover encounters a hazard. This drive brings the odometer 1,998 meters (1.24 miles).