After so much driving on sol 134, Spirit got a break and spent sol 135 doing in-situ science investigations of its surroundings. It began the sol observing nearby soil with the alpha particle X-ray spectrometer and Moessbauer spectrometer. It then used the microscopic imager to see the soil up close. After stowing the instrument deployment device, Spirit used its wheels to dig a trench and then imaged the trench with the cameras on the mast.

Spirit's odometer now reads 2,585.52 meters (1.6 miles). The rover still has 680 meters (0.42 miles) to go before reaching the base of the "Columbia Hills," but will likely get there before sol 160.

Daily Update - 5/26/04
Opportunity on the Edge
Opportunity Status for sol 115-116

On Sol 115 Opportunity drove 11.7 meters (38.4 feet), coming to rest about 3 meters (10 feet) from the edge of "Endurance Crater," as intended. Rover planners had commanded Opportunity to go 10 centimeters (3.9 inches) farther, but the rover decided to stop when it "saw" the edge of the crater in the navigation camera images. This was actually a more conservative response than necessary, as it would have been safe to complete the drive. Rover planners are looking into changing the way they send commands to prevent this over-conservatism next time.

Opportunity used its navigation camera to acquire images showing its proximity to the crater. On Sol 116 Opportunity turned slightly to the right and crept a little closer to the edge of Endurance Crater to get into just the right position to set up camp for a few sols. The rover executed this 1.5 meter (4.9 feet) traverse as planned, ending up facing northwest with a total tilt of about 8 degrees pitched "nose-up". From this position, Opportunity will make many observations with the panoramic camera and mini thermal emission spectrometer to fully characterize the parts of the crater that can be seen from here. Opportunity now sits only about 1 meter from the edge of the crater, and there is a sloping drop-off of about 40 degrees dead ahead.

Daily Update - 5/20/04
Spirit Gets an Unexpected Break
Spirit Status for sol 131-133

Spirit continued its trek to the "Columbia Hills" over the past four sols, but took an unplanned break on Sols 131 and 132 due to a software fault on sol 131. That fault left rover planners with some uncertainty about Spirit's final position and attitude, so Sol 132 was spent re-establishing that knowledge with panoramic, navigation and hazard avoidance camera imaging of the rover's surroundings. The unplanned break did have a silver lining though; it resulted in fully charged batteries, paving the way for a long drive on Sol 133. Spirit roved 113 meters (370.7 feet) on Sol 133, with a record 78-meter (256 feet) autonomous navigation segment. The previous record for an autonomous navigation drive was 62 meters (203.4 feet) on sol 125. Spirit's odometer now reads 2473 meters (1.53 miles) and it is roughly 780 meters (.5 miles) from the Columbia Hills and in excellent health.

So what went wrong on sol 131? The flight software team is uncovering the details, but it appears that the error occurred within a 3-microsecond window of vulnerability when a "write" command was attempted to a "write-protected" area of RAM. The flight software team believes this is an extremely low probability event, and has not adjusted the planning process to avoid the miniscule period of vulnerability. Opportunity has the same vulnerability to the fault.

Daily Update - 5/18/04
A Sol for Rest and Recharging
Opportunity Status for sol 112

Opportunity is healthy, but feeling a bit sluggish today. The rover’s 40-meter (131 feet) traverse along the southern edge of "Endurance Crater" on sol 111, and a sol 112 error with a Deep Space Network command transmission have resulted in a low battery state of charge.

The sol 111 drive put Opportunity on an 8-degree slope that tilted the rover away from the Sun and limited the amount of direct sunlight that could reach the solar panels.

To help the battery recover to its normal state of charge, rover planners had built a sol 112 plan that deleted two of the three UHF windows. Unfortunately, a Deep Space Network configuration error prevented the command load from reaching Opportunity on sol 112 and, as expected in such cases, the rover executed the onboard run-out sequence, which included an hour of remote sensing and the three on-board UHF communication windows.

Sol 113 will be a sol for sleep and recharging for Opportunity. On sol 114, the rover will do some limited remote sensing in the morning, but will generally take it easy over the next few sols in order to fully charge the batteries. The limited activity over the next few sols will focus on moving towards the Endurance Crater rim and a new position for panoramic camera imaging.

Daily Update - 5/17/04
Spirit Roving Right Along
Spirit Status for sol 127-130

Spirit spent most of sol 127 continuing its drive toward the "Columbia Hills." The rover put approximately 70 more meters (229.7 feet) on its odometer and then took an hour-and-20-minute siesta. After the drive, Spirit took observations with the panoramic camera, navigation camera and mini thermal emission spectrometer.

Spirit began sol 128 by completing a panoramic camera observation of a rock target called "Flat Head." The rover then rested up for a couple of hours before embarking on a 90-meter (295 feet) drive toward the hills. Once the drive was complete, Spirit completed its standard post-drive observations.

Sol 129 began successfully, but Spirit encountered a couple of difficulties before the martian day was over. After waking, Spirit performed 45 minutes of science observations and then settled down for a morning nap. With plenty of energy stored, it was time to drive. Spirit roved 31 meters (102 feet) across the surface in an engineer-directed drive and then spent 45 minutes using its autonomous navigation system to try to drive down the side of a small ridge. The backside slope of the ridge was too steep, and the autonomous navigation system had Spirit turn in an attempt to find another way down. Unfortunately, a couple of large rocks close to the ridge prevented Spirit from finding a safe path down. At the end of the drive sequence, Spirit was supposed to complete a "stutter step" to get in proper position to do work with the instrument deployment device on sol 130. Unfortunately, the rover was unable to complete this final positioning or the ultimate post-drive imaging, so sol 130 was mostly a drive sol.

Spirit has 2,291.92 meters (1.4 miles) on its odometer and is approximately 936 meters (.6 miles) from Columbia Hills. The rover is on track to reach the Columbia Hills by sol 160.

Daily Update - 5/17/04
Opportunity Digs, Scuffs, and Cruises
Opportunity Status for sol 107-111

On sol 107, Opportunity successfully drilled a hole into "Lion Stone" with the rock abrasion tool. Since the surface of the rock was fairly uneven, the tool had to work through some high spots before getting a good bite on the rock for a full circular hole. Sol 107 ended at 6:44 a.m. May 13 PDT, with a nighttime integration of the alpha particle X-ray spectrometer to reveal elemental composition of the inner part of the rock.

On Sol 108, which ended at 7:24 a.m. May 14, PDT, the rover finished up its work on Lion Stone by analyzing the rock abrasion tool hole with the Moessbauer spectrometer and taking microscopic images to create a mosaic of the hole. Opportunity then moved away from Lion Stone and continued traversing counterclockwise around the crater. Opportunity drove 32 meters (105 feet) to the top of a small ridge for a better view of where to drive on Sol 109.

On Sol 109 and sol 110, which ended at 8:04 a.m. May 15, PDT, and 8:43 a.m. May 16, PDT, respectively, Opportunity drove about 41 meters (135 feet) each sol. Opportunity ended the drive on May 16 with a "scuff" of the soil and rocks under the front wheel. This scuff action produced an interesting dislodged plate of some kind. The scientists will be making some additional observations of different pebbles on the ground in the sol 111 plan.

Opportunity is driving along the south edge of Endurance Crater, with a southward tilt of about 8 degrees. The Sun is now at higher latitudes (south hemisphere winter is coming), so a southward tilt robs the rover of total solar array energy. This is making it more difficult to perform many activities. In a couple of sols when Opportunity drives to flatter ground near the crater edge to take the next large panorama, the energy situation is expected to improve.

Opportunity has driven a total of 1,170 meters (3,839 feet or 0.7 miles).

Daily Update - 5/13/04
Crater Cruise
Opportunity Status for sol 103-106

On Sol 103, Opportunity traversed approximately 13 meters (about 43 feet) farther south along the eastern rim of "Endurance Crater," reaching the beginning of the "Karatepe" area. On sol 104, the rover approached "Lion Stone," a rock at the crater’s edge that stands about 10 centimeters tall (about 4 inches) and is about 30 centimeters long (12 inches). This brought Opportunity's total mission odometry to 1,054meters (3,458 feet)!

On Sol 105, Opportunity acquired a series of microscopic images of Lion Stone and the surrounding soil.

The rover then went on to collect a short Moessbauer integration on the rock during the day, performed a tool change to the alpha particle X-ray spectrometer in late afternoon, and acquired that integration in the early morning of Sol 106. That sol also included additional microscopic images and a successful "bump" maneuver to reposition the rover so the top of Lion Stone was in position for the rock abrasion tool on Sol 107. Remote sensing was also acquired during the two sols, including panoramic camera images of the heatshield that protected Opportunity during its toasty trip through the martian atmosphere. The heatshield impacted approximately 250 meters (about 820 feet) south of Endurance Crater.

Plans for Sol 107 are to perform a rock abrasion tool grind on Lion Stone with subsequent microscopic images and alpha particle X-ray spectrometer overnight integration. The tentative plan for Sol 108 is to leave Lion Stone and begin traverse to observation position 2 on the southeastern rim of Endurance Crater.

Daily Update - 5/12/04
Spirit Speeds to 'Lead Foot'
Spirit Status for sol 124-126

Spirit drove 80 meters (262.5 feet) on sol 124, bringing its total odometry to 1,909.52 meters (1.2 miles). Spirit has less than 1.2 kilometers (.75 mile) to go before reaching the base of the"Columbia Hills," and will reach them by sol 160. Later in the martian day, after completing the sol 124 drive, Spirit took a 360-degree afternoon panorama of its surroundings with the navigation camera.

On sol 125, Spirit continued driving and set a new one-sol driving record of 123.7 meters (405.8 feet). Science on Sol 125 included morning atmospheric sky and ground remote sensing, mini thermal emission spectrometer observation of the sol 126 instrument deployment device work volume, imaging with the panoramic camera, and cloud observations.

After the long sol 125 drive, Spirit was in perfect position to work with the instrument deployment device on sol 126. This included alpha particle X-ray spectrometer, Moessbauer and microscopic imager work on a target called "Lead Foot" (in honor of the big drive on sol 125). The Moessbauer was used as the feeler for all these activities but touched down on rocks rather than soil at the "Lead Foot" location, compromising the Moessbauer and microscopic imager data (images out of focus). Spirit also did some driving on this sol, and added 55.6 meters (182.4 feet) to the odometer, bringing Spirit's new drive total to 2,089 meters (1.3 miles). At the end of the sol, Spirit successfully executed a sequence that used the panoramic camera to find the Sun and correct for accumulated rover attitude errors.

Daily Update - 5/10/04
'Deep Sleep' Gives Opportunity More Energy to Cruise the Crater
Opportunity Status for sol 101-102

Opportunity awoke on sol 102 from its first "deep sleep." This set of activities was initiated to conserve the energy that is being used by the instrument arm's stuck-on heater switch. During deep sleep, rover planners power off the main electronics at night and open the switches that supply battery power to the main power bus, and in turn nearly all the secondary electronics. In particular this removes power input to the Rover Power Distribution Unit, which normally supplies power to the stuck-on heater. With the Rover Power Distribution Unit input turned off, the heater cannot burn any energy either. In the morning, when the sun strikes the solar panel array, the Battery Control Board resets and connects the batteries to the main power bus again. At this time, the stuck-on heater again draws power, but this will only be for a few hours in the morning instead of all night.

The most vulnerable instrument to the cold martian nights is the miniature thermal emission spectrometer. With a cutoff of the power electronics, its heater cannot keep it warm overnight. Data returned on sol 102 showed the temperature reached -46 degrees Celsius (-50.8 degrees Fahrenheit), a bit warmer than the spectrometer's lowest proven temperature for functionality, -50 degrees Celsius (-58 degrees Fahrenheit).

Rover planners commanded Opportunity to take a drive during the afternoon of sol 102 to the south, along the edge of the crater toward a dark rock in the vicinity.

More remote sensing was conducted, including miniature thermal emission spectrometer measurements that confirmed the instrument is still functioning normally after deep sleep.

Wake-up songs for the sols were "Morning has Broken" by Cat Stevens; "Hallelujah Chorus" from George Frideric Handel's Messiah; and "Dazed and Confused" by Led Zeppelin.

Daily Update - 5/10/04
Spirit Surpasses the One-Mile Mark!
Spirit Status for sol 121-123

On sol 121, after a brief nap, Spirit conducted atmospheric measurements before continuing its trek toward the "Columbia Hills." A 96.8 meter (318 feet) drive that consisted of about half direct drive and half auto-navigational drive broke Spirit's last one-sol distance traveled. That drive brought the mission total to 1,669 meters (1.04 miles), flipping the rover's odometer over the one-mile mark.

Sol 122 was a touch-and-go day, starting with a half-hour alpha particle X-ray spectrometer integration, a one-hour Moessbauer integration and a set of four microscopic images all on the same patch of soil. Panoramic camera and miniature thermal emission spectrometer data were also obtained before an afternoon nap. The bulk of the afternoon was spent driving another 65 meters (213 feet).

Sol 123 started off with Panoramic camera and miniature thermal emission spectrometer observations for near-field surveys, atmospheric studies, and localization. Spirit then took a half-hour nap, followed by the day's drive. This sol consisted of another 48-meter (about 157-feet) direct drive, the mid-drive survey and localization remote sensing, and then 47-meters (about 154 feet) of driving using auto-navigation. The total was 95.2 meters (312 feet), bringing the mission total to 1830 meters (1.14 miles).

Daily Update - 5/6/04
'Columbia Hills' on the Horizon
Spirit Status for sol 118-120

Spirit is now approximately 1.7 kilometers (1 mile) away from the base of the "Columbia Hills" after three long sols of driving. Its odometer currently reads 1,566 meters (.97 miles) and counting.

Sol 118 was a record-breaking driving sol for Spirit. The Gusev Crater rover moved 92.4 meters (303 feet) across the surface in one sol, breaking its previous record of around 90 meters (295 feet). The Opportunity rover still has Spirit beat with a one-sol driving record of 140 meters (459.3 feet).

Sol 119 proved to be a more difficult sol for Spirit. An uplink configuration error prevented the sequence load from successfully getting on board the rover. Rover controllers took advantage of the down day by deleting afternoon communication sessions and enabling the rover to charge its battery during a long afternoon nap.

It was back to business as usual on sol 120. Before embarking on its drive, Spirit imaged a rock called "Tulula" with the panoramic camera. The rover then successfully executed a blind drive before using the autonomous navigation system to continue into uncharted territory. After reaching the time-of-day driving limit, Spirit turned and performed penultimate (next to last stop) imaging. The next move would have taken the rover 85 centimeters (33.5 inches) to its ultimate stopping point, but did not execute because Spirit was facing a small sand ridge that was perceived as a hazard. Without a penultimate/ultimate image pair, rover controllers could not be sure that the area underneath the rover was clear of hazards for instrument arm deployment. As a result, Sol 121 will be another driving sol that controllers hope will place Spirit in a suitable location to use the instruments on its instrument deployment device.

Daily Update - 5/6/04
An Eyeful at 'Endurance'
Opportunity Status for sol 98-99

Opportunity continues to gaze at the incredible "Endurance Crater" from its vantage point on the western rim. Remote sensing, including gathering of imagery of two potential traverse targets just inside the northern edge and southwestern edge of the crater, will continue on the rover's 100th sol.

Daily Update - 5/3/04
Spirit explores the 'Big Hole' trenc
Spirit Status for sol 114-117

On Sol 114, which ended at 9:49 a.m. April 29 PDT, Spirit performed a lot of science activities in the trench called "Big Hole" using the microscopic imager, Moessbauer spectrometer and alpha particle X-ray spectrometer. Opportunity also studied the rover tracks and the crater rim.

Sol 116 started with a repeat of the microscopic imaging of a target in the trench due to minor communication glitches on sol 115. Spirit then stowed the arm, backed away from Big Hole trench, and took panoramic camera images of the trench before it continued on its trek toward the Columbia Hills. The drive on sol 116, which ended at 11:08 a.m. May 1 PDT, established a new drive record of 90.8 meters (298 feet) for Spirit!

On sol 117, which ended at 11:47 a.m. May 2, Spirit drove 37 meters (121 feet) to a small ridge, where the vehicle experienced a pitch up of 12.2 degrees. Engineers believe that the change in tilt caused the vehicle to recompute its "goodness map," which helps the rover autonomously drive over the martian terrain, and the rover declared that it was not safe to continue its drive. One good thing that came out of this is that the end-of-drive tilt positioned the solar arrays to maximize afternoon solar exposure, and the rover's battery state of charge is in good health.

Daily Update - 5/3/04
Opportunity Arrives at 'Endurance Crater'
Opportunity Status for sol 94-97

After a 50-meter (164-foot) drive on sol 94, which ended at 10:10 p.m. April 29 PDT, and the final approach of 17 meters (56 feet) on sol 95, which ended at 10:49 p.m. April 30 PDT, Opportunity arrived on the western rim of "Endurance Crater" and began surveying the spectacular new view.

Opportunity sits about half a meter (1.6 feet) outside the edge of the crater with a positive pitch of 4.7 degrees, meaning the rover is slightly tilted with its head up. The western side of the crater rim slopes down in front of Opportunity with an angle of about 18 degrees for about 17 meters (56 feet).

Sols 96 and 97, which ended at 11:29 p.m. May 1 PDT, and 12:08 a.m. May 3 PDT respectively, focused on remote sensing of Endurance Crater and the interesting features in and around it.

All systems are healthy and Opportunity's batteries are near a full state of charge.

The plan for sols 98 and 99, which end at 12:48 a.m. May 4 PDT and 1:28 a.m. May 5 PDT respectively, is to take advantage of Opportunity's current vantage point and take high-resolution miniature thermal emission spectrometer readings of the far crater wall.