Afterwards, Spirit rolled backward 85 centimeters (2.8 feet) to a position from which it could use its miniature thermal emission spectrometer on the cleaned areas for assessing what minerals are present. Due to caution about potential hazards while re-approaching "Humphrey," the rover moved only part of the way back. Plans for sol 56, ending at 6:33 p.m. Sunday, PST, call for finishing that re-approach and further inspecting the brushed areas. If all goes well, the rock abrasion tool's diamond-toothed grinding wheel will cut into the rock on sol 57 to expose fresh interior material.

For wake-up music on sol 55, controllers chose "Brush Your Teeth," by Cathy Fink and Marcy Marxer, and "Knock Three Times," by Tony Orlando and Dawn.

Daily Update - 2/29/04
Guadalupe Under the Microscope
Opportunity Status for sol 35

During its 35th sol on Mars, ending at 6:14 a.m. Sunday, PST, Opportunity manipulated the microscopic imager at the tip of its arm for eight observations of the fine textures of an outcrop-rock target called "Guadalupe." The observations include frames to be used for developing stereo and color views.

Opportunity also used its Moessbauer spectrometer and, after an overnight switch, its alpha particle X-ray spectrometer to assess the composition of the interior material of "Guadalupe" exposed yestersol by a grinding session with the rock abrasion tool.

The panoramic camera up on the rover's mast captured a new view toward the eastern horizon beyond the crater where Opportunity is working, for use in evaluating potential drive directions after the rover leaves the crater.

Jimmy Cliff's "I Can See Clearly Now," was played in the mission support area at JPL as Opportunity's sol 35 wake-up music.

Plans for sol 36, ending at 6:54 a.m. Monday, PST, called for finishing the close-up inspection of "Guadalupe," then backing up enough to give the panoramic camera and miniature emission spectrometer good views of the area where the rock interior has been exposed by grinding.

Daily Update - 2/28/04
Scratch and Sniff
Opportunity Status for sol 34

Opportunity remains healthy and active. During its 34th sol on Mars, which ended at 5:34 a.m. Saturday, PST, the rover used its rock abrasion tool for the second time. It ground the surface off a patch of rock at a site called "Guadalupe" in the outcrop the rover has been examining. The rover looked at the patch with its microscope both before and after the grinding session. Then it placed its Moessbauer spectrometer against the newly exposed interior material of the rock for a long reading of data that scientists use to identify what iron-containing minerals are present in the target.

Opportunity also used its miniature thermal emission spectrometer during the sol to assess the composition of an outcrop feature dubbed "Shoemaker Wall." It took images of "Guadalupe" with its panoramic camera before and after the use of the rock abrasion tool.

Wake-up music played in the mission support area at JPL for sol 34 was "Dig In," by Lenny Kravitz.

For sol 35, ending at 6:15 a.m. Sunday, PST, plans call for continuing use of tools on the robotic arm to examine the rock interior exposed by the "Guadalupe" grind.

Daily Update - 2/27/04
Heading To 'Humphrey'
Spirit Status for sol 54

On sol 54, Spirit woke up to the song "Big Rock in the Road" by Pete Wernick and made its final approach to the imposing rock called "Humphrey" before the sol ended at 5:13 p.m. PST on Friday, Feb. 27. The initial 3.5 meter (11.5 feet) drive toward the rock was cut short at only 2.5 meters (8.2 feet) due to a built-in software safety. Rover engineers quickly adjusted the software restriction and drove the final meter of that planned drive, plus the 0.9 meters (about 3 feet) that put the rover in the best position for brushing "Humphrey" with the rock abrasion tool.

Before approaching the rock, Spirit used its alpha particle X-ray spectrometer to investigate the areas the rock abrasion tool will brush and grind. Unlike the last rock abrasion tool sequence on the rock called "Adirondack," the planned procedure for "Humphrey" will include brushing three separate areas of the rock. After brushing, Spirit will back up and examine the brushed areas with the instruments on its arm. The science team will then decide the best place to grind into "Humphrey" – it could be one of the three brushed areas or another section altogether. The hope is to remove as much dust as possible so the instruments on Spirit’s arm can get a pre-grinding "read" on the rock coating and then, after grinding, study beneath the coating and surface.

In the sols following the rock abrasion tool sequence, Spirit might investigate an interesting rock behind it, or continue on toward "Bonneville" crater.

Daily Update - 2/27/04
Biting Blueberry Hill
Opportunity Status for sol 33

On sol 33, which ended at 4:55 a.m. Friday, February 27, Opportunity reached its second rock abrasion tool target site, and it’s ready to take the next bite of Mars.

Opportunity woke up a little late on sol 33 to conserve energy. The wake-up song was 'Blueberry Hill' by Fats Domino, in honor of the hill in front of the rover.

Opportunity took an early afternoon 360-degree panorama and an extra observation of the area to the east with its navigation camera, while the Moessbauer instrument completed the measurements it began on sol 32.

The microscopic imager also took three sets of observations of the hole created by the rock abrasion tool on sol 30. Opportunity later took stereo images of the rock area named "Maya" and took pictures of an area called "Half-Dome." Both the panoramic camera and the miniature thermal emission spectrometer observed the sky.

In between science measurements, Opportunity stowed its instrument arm and drove a 15-centimeter (6-inch) "bump" to reach its next rock abrasion tool target. Final shutdown was at 2:37 Local Solar Time, with a brief wakeup at 4:10 Local Solar Time to transmit data to the Mars Odyssey orbiter as it flew over the rover.

The plan for the weekend is to grind into the upper part of "El Capitan" dubbed "Guadalupe" and to take extensive measurements of the new hole using the microscopic imager and two spectrometers.

Daily Update - 2/26/04
Eyeing Martian Dust Devils
Spirit Status for sol 53

On sol 53, which ends at 4:34 p.m. PST on February 26, Spirit woke up to the 70s ballad "Dust in the Wind" by Kansas, with the anticipation of possibly capturing dust devils spinning across the martian surface. The rear hazard avoidance camera was commanded to "roll tape" from 12:00 to 12:30 local solar time to record these so-called "mini-tornadoes." The behavior of dust devils helps scientists track the transfer of dust on the red planet.

A final, .85-meter (about 2.8 feet) drive brought Spirit to its exact target at the "Middle Ground" site. The rover also conducted an examination, using its microscopic imager and alpha particle X-ray spectrometer, of the magnet arrays that are collecting airborne dust.

In the coming sols Spirit will inspect the soil at its current position with the tools on its arm. Following that, the plans call for the rover to approach the rock called "Humphrey." After a thorough assessment of "Humphrey," the rock abrasion tool will be used to brush and then grind.

Daily Update - 2/26/04
New Communications Plan
Opportunity Status for sol 32

On sol 32, which ended at 4:15 a.m. Thursday, February 26, Opportunity awoke to "Let It Be" by the Beatles. Opportunity's day was focused on getting a second Moessbauer instrument measurement of the hole created by the rock abrasion tool at the "McKittrick" rock site. The Moessbauer can detect spectral signatures of different iron-bearing minerals.

The data from the first Moessbauer spectrum of "McKittrick" was received on Earth Wednesday afternoon. The alpha proton X-ray spectrometer data from yestersol at this target was retransmitted to Earth again Wednesday to get missing packets of data that were not received during the first data communications relay. Opportunity also snapped pictures of the rock areas named "Maya" and "Jericho" with the panoramic camera and took miniature thermal emission spectrometer measurements of the sky and "El Capitan" throughout the sol.

The amount of power Opportunity is able to generate continues to dwindle due to the decreasing amount of sunlight (energy) reaching the solar panels during the martian seasonal transition to winter. Because of this, the engineers are adjusting the rover’s daily communications activities. To minimize power use for communications sessions, engineers began a new "receive only" morning direct-from-earth communication relay. This lower-power communication mode was successful. Opportunity will continue with this approach to maximize the available power for driving and science activities as Mars moves farther away from Earth and the Sun in its elliptical orbit.

In conjunction with the morning communications session change, engineers added a second afternoon Mars Odyssey orbiter relay pass, which uses less power in transmitting data volume than direct-to-Earth communication. This additional Odyssey pass more than compensated for the elimination of the morning direct-to-Earth downlink. Engineers also continue to effectively use rover "naps" throughout the day to maximize energy savings.

The plan for sol 33, which ends at 4:55 a.m. Friday, February 27, is to take a very short trip (10 to 20 centimeters or 4 to 8 inches) towards the next rock abrasion tool target site, "Guadalupe."

Daily Update - 2/25/04
Spirit Looks Back at Earth
Spirit Status for sol 52

On sol 52, which ended at 3:54 p.m. PST, February 25, rover engineers drove Spirit the short 4-meter (13.1 feet) drive to "Middle Ground" after finishing observations with the miniature thermal emission and Moessbauer spectrometers. Several stutter steps that would have put Spirit at the exact target location were not executed because they were programmed with built-in safeties. The rover detected slight hazards and stopped within its constraints. The final steps will be executed next sol.

Waking up to Foreigner's "Cold as Ice," Spirit's first job of the sol was to warm up its arm that was significantly colder than yestersol due to the rover's orientation to the northwest. The engineering team also took a moment to wave to Spirit as its panoramic camera faced and imaged Earth.

Spirit will remain at "Middle Ground" for the next several sols and continue observing targets with its spectrometers and microscopic imager. Plans also call for high-resolution images of rocks and an examination of the soil.

Daily Update - 2/25/04
Opportunity Gets an Attitude Adjustment
Opportunity Status for sol 31

On sol 31, which ended at 3:36 a.m. Wednesday, February 25, Opportunity awoke to "Rock Around the Clock" by Bill Haley and his Comets. At 1:00 a.m. Local Solar Time, Opportunity sent data to Earth via the Mars Global Surveyor orbiter and then sent another whopping 145.6 megabits of data at 3:30 a.m. Local Solar Time via the Mars Odyssey orbiter.

During the morning hours, Opportunity collected data with the alpha particle X-ray spectrometer for five hours and took measurements with its miniature thermal emission spectrometer from inside its newly formed hole that was created on sol 30 by the rock abrasion tool. Later, Opportunity retracted and closed the door of the alpha particle X-ray spectrometer and swapped the Moessbauer spectrometer into the hole made by the abrasion tool for a leisurely 24-hour observation.

Opportunity also updated its "attitude knowledge," which fine-tunes the rover's information about its exact location and position on Mars. Updating the attitude knowledge allows the rover to more accurately point the high gain antenna toward Earth, which increases the communications capabilities. The attitude adjustment also enables scientists and engineers to point instruments onboard Opportunity more precisely at targets of interest, such as particular rocks and patches of soil. To adjust the attitude knowledge, engineers have the rover turn the panoramic camera to the Sun and watch the Sun travel across the sky for 15 minutes. The rover is then smart enough to take the Sun movement data collected from the panoramic camera to calculate its own location in the universe…..on Mars. The rover gathers attitude knowledge errors over time as it drives and uses the robotic arm extensively, but it only needs an attitude adjustment about once a week or after driving long distances.

Around 12:15 pm Local Solar Time, Opportunity went to sleep to recharge its batteries from its strenuous rock abrasion tool activities on sol 30, but reawakened briefly at 4 p.m. Local Solar Time and again in the evening to send data to Earth via additional overflights by the Mars Global Surveyor and Odyssey orbiters.

The plan for sol 32, which ends at 4:15 a.m. Thursday, February 26, is to take another unique set of Moessbauer measurements to look at the rover-created hole in a different spectrum. The goal is to then crawl slightly forward on sol 33 to position Opportunity to use the rock abrasion tool on the upper target of the El Capitan/McKittrick area.

Daily Update - 2/24/04
Making Ground
Spirit Status for sol 51

To inspire a morning "run" on sol 51, which ended at 3:15 p.m. Tuesday, PST, Spirit woke up to Vangelis’ "Chariots of Fire." The rover deployed its arm, took microscopic images of the soil in front of it and then proceeded toward its target, "Middle Ground." Spirit drove 30 meters (98.4 feet), breaking its own record for a single-sol traverse. Along the way, Spirit paused to image rocks on both sides of the drive path with its panoramic camera.

The auto-navigational software that drove the last 12 meters (39.4 feet) of the traverse to the "Middle Ground" target warned Spirit that the slope into the hollow that houses it was too steep (according to parameters set by rover engineers). Spirit then paced along the rim, looking for a safe way down. Unable to locate a secure path into the crater before the sol ended, Spirit ended up facing slightly west of north instead of northeast, as called for by the plan. This orientation will reduce the amount of data the rover can return (due to interference between the UHF antenna and items on the rover equipment deck), but it will be corrected in the coming sols.

As of today, Spirit has moved 183.25 meters (601.21 feet) and is now roughly 135 meters (442.91 feet) from its landing site, Columbia Memorial Station.

The intent for the next several sols will be to drive Spirit into "Middle Ground" and take a full panorama of the surrounding area to identify scientifically interesting rocks.

Daily Update - 2/24/04
A Beautiful Grind
Opportunity Status for sol 30

On sol 30, which ended at 2:56 a.m. Tuesday, February 24, Opportunity performed its first rock abrasion tool operation on a rock target known as 'McKittrick Middle Rat' at the El Capitan site inside the crater. The tool shaved the rock over a period of two hours, grinding into a total depth of about 4 millimeters (.16 inches).

The auspicious day began with the song 'Rock'n Me' by Steve Miller and some miniature thermal emission spectrometer sky surveys and sky stares to study the atmosphere. After completing these activities, Opportunity took a short siesta to recharge its batteries. The rover has been doing a lot of science work at night, and the season on Mars is changing to winter, so the rover has less energy to work with than it did earlier in the mission. The martian days are getting shorter and the sun angle is not allowing either rover to power up the solar panels as much as in the past.

Opportunity woke up from its nap at 11:30 Local Solar Time on Mars to run through the series of commands required to retract the alpha particle X-ray spectrometer and close its doors; take several microscopic images of another nearby rock abrasion tool target called 'Guadalupe;' flip the wrist; take a microscopic image of "McKittrick Middle Rat;" and place the rock abrasion tool on its target to run at 13:00 Local Solar Time.

After the abrasion tool was retracted, a series of microscopic images of the scene were taken, and the alpha particle X-ray spectrometer was successfully placed into the abrasion tool's hole late in the day.

Some additional panoramic camera, miniature thermal emission spectrometer readings, and hazard avoidance camera imagery was completed through the day.

The plan for sol 31, which will end at 3:36 a.m. Wednesday, February 25, is to continue getting long Moessbauer readings of the rock abrasion tool hole and to prepare the tool for more work again on sol 33 or 34.

Daily Update - 2/23/04
Heading for Middle Ground
Spirit Status for sol 50

On Sol 50, ending at 2:35 p.m. PST, Spirit finished observations of the trench at "Laguna Hollow," then continued on its journey toward the crater called "Bonneville." Driving in a dog-leg pattern to avoid some bumpy terrain, Spirit traveled approximately 18.8 meters (61.7 feet) toward the halfway point, called "Middle Ground." The last 2.8 meters (9.2 feet) were covered using autonomous navigation software.

After completing the drive, Spirit gathered miniature thermal emission spectrometer data on the ground on both sides of the rover, and its panoramic camera and navigation camera took pictures.

The wake-up song this morning (Sunday evening Pacific time) was "Samba De Marte" by Beth Carvalho from her "Perolas Do Pagode" album. The lyrics include a verse about waking up the rover on Carnival Day. This song was written by Beth Carvalho after she heard that one of her songs was used to wake up Mars Pathfinder's Sojourner rover during the 1997 mission. This is quite appropriate, as this spirited sol 50 also began on Carnival day in Brazil!

In the coming sols, Spirit will complete the drive to "Middle Ground."

Daily Update - 2/22/04
Trench Exam Continues
Spirit Status for sol 49

Spirit continued its inspection of the trench dubbed "Road Cut" during the rover's 49th sol, ending at 1:56 p.m. Sunday, PST. It used three instruments on its robotic arm to examine the subsurface soil exposed by the sol 47 digging of the trench.

Before dawn on sol 49, Spirit switched from its Moessbauer spectrometer to its alpha particle X-ray spectrometer for analysis of soil on the trench floor. Later, controllers played "Coisinha do Pai," by Beth Carvalho, as wake-up music. The rover inspected targets on the wall and floor of the trench with its microscope, then placed the Moessbauer spectrometer against a target on the trench wall for identifying the iron-bearing minerals there. The miniature thermal emission spectrometer took remote readings on the rover's wheel tracks in the morning and afternoon.

Plans for sol 50 (ending at 2:35 p.m. Monday, PST) call for finishing inspection of the trench, then resuming the journey toward the rim of a crater dubbed "Bonneville," followed by a longer drive the following sol.

Daily Update - 2/22/04
Busy Microscope at "El Capitan"
Opportunity Status for sol 28

On sol 28, which ended at 1:38 a.m. Sunday, PST, Opportunity moved its arm repeatedly to make close-up inspections the "El Capitan" part of the street-curb-sized outcrop in the crater where the rover is working. Opportunity took 46 pictures with its microscope, examining several locations on "El Capitan" at a range of focal distances. It also placed its Moessbauer spectrometer and its alpha particle X-ray spectrometer on the rock target to assess what minerals and what elements are present.

Controllers chose the song "I am a Rock," performed by Paul Simon and Art Garfunkel, as Opportunity's sol 28 wake-up music. The sol's activities included observations by the miniature thermal emission spectrometer and the panoramic camera, as well as the use of the tools on the arm.

The arm's complex maneuvers totaled 25 minutes of actual arm movement. Rover planners' success in accomplishing them drew a round of applause in the Mission Support Area at JPL during the afternoon downlink from Mars.

During the martian night, early on sol 29, Opportunity woke up and moved its arm again to switch from the Moessbauer spectrometer to the alpha particle X-ray spectrometer. Additional close-up inspections are planned for later in sol 29, which ends at 2:17 a.m. Monday. Plans for sol 30 feature the use of the rock abrasion tool to grind through the surface at one target on "El Capitan."

Daily Update - 2/21/04
Down in the Trench
Spirit Status for sol 48

On its 48th sol, ending at 1:16 p.m. Saturday, PST, Spirit maneuvered its robotic arm successfully within the challengingly tight confines of the trench that the rover had dug into the floor of "Laguna Hollow" the preceding sol.

Spirit used the microscopic imager on the arm to take pictures of details in the wall and floor of the trench during the morning. Then Spirit rotated the tool turret at the end of its arm and placed the Moessbauer spectrometer in position to read the mineral composition of the soil on the trench floor. That reading was designed to last about 12 hours, from mid-sol into the martian night. Spirit's panoramic camera and miniature thermal emission spectrometer were also used during the sol for studies of sky and rocks.

Spirit has been told to wake up and switch from the Moessbauer spectrometer to alpha particle X-ray spectrometer on the trench floor during the pre-dawn hours of the next sol. Later on sol 49 (which ends at 1:56 p.m. Sunday) and early on sol 50, plans call for using those spectrometers on the walls of the trench and making additional observations of the "Laguna Hollow" area. Then Spirit is slated to resume its trek toward the rim of the crater nicknamed "Bonneville," now estimated to be about 135 meters (443 feet) northeast of the rover's current location.

Daily Update - 2/21/04
Supersized Science
Opportunity Status for sol 27

On sol 27, ending 12:57 a.m. Saturday, PST, Opportunity successfully "supersized" the measurements of the "El Capitan" area with the panoramic camera, miniature thermal emission spectrometer, and microscopic imager. The rover team is analyzing "super resolution" and "super spectral" observations from the science instruments and currently locating the best spots to place the rock abrasion tool.

Opportunity also drove 33 centimeters (13 inches) closer to "El Capitan" to better poise the robotic arm for use of the rock abrasion tool sometime over the next four or five sols, which will be the first use of the rock abrasion tool by Opportunity.

On sol 28, ending at 1:38 a.m. Sunday, PST, plans call for Opportunity to take extensive microscopic images of "El Capitan," which is a rich science target because it has multiple layers and varied textures on the upper and lower areas of the rocks, implying multiple changes in the geologic history of this area.

The Mars Odyssey orbiter is scheduled to fly over Opportunity during sol 28 with increased data communications capabilities to 256 kilobits per second, which is five times the speed of normal home computer modems.

Daily Update - 2/20/04
Spirit Digs a Trench
Spirit Status for sol 47

On sol 47, ending at 12:36 p.m. February 20, 2004 PST, engineers woke Spirit up to the song "Dig Down Deep," by Hot Soup, and that's exactly what Spirit proceeded to do. The two-hour operation performed by Spirit's left front wheel resulted in a trench 7-8 centimeters deep (2.8 to 3.1 inches) that uncovers fresh soil and possibly ancient information.

Spirit dug this trench at "Laguna Hollow" the same way that Opportunity dug its 9-10 centimeter (3.5 to 3.9 inch) trench at Meridiani. However, because the ground at this location is harder, Spirit had to dig for twice as long as Opportunity – going back and forth over the surface 11 times instead of 6.

After the trench was completed, Spirit backed up one meter, or more than a yard, and analyzed the area with the miniature thermal emission spectrometer before driving forward 0.4 meters (15.7 inches) and imaging the excavation site with the panoramic camera. A final move forward of another 0.4 meters allowed Spirit to take front hazard avoidance camera images of the arm work volume which was then centered on the trench.

After stowing the arm, the rover did a series of miniature thermal emission spectrometer observations of several nearby rocks, "Buffalo," "Cherry," "Cotton," and "Jiminy Cricket," and a combined miniature thermal emission spectrometer and panoramic camera observation of "Beacon." Spirit also took panoramic camera images of its deck to observe dust accumulation on the instrumented solar cells and on the miniature thermal emission spectrometer calibration target.

Spirit then took a siesta from 2 p.m. to 3:45 p.m. Mars Local Solar time and woke up for some more panoramic camera and miniature thermal emission spectrometer observations of "Beacon," and miniature thermal emission spectrometer ground and sky stares. All activities up through the afternoon pass by the Mars Odyssey orbiter were completed successfully.

Daily Update - 2/20/04
Enter the Rock Abrasion Tool
Opportunity Status for sol 26

On sol 26, which ended at 12:18 a.m. Friday, February 19, PST, Opportunity successfully obtained one final Moessbauer spectrometer reading of the trench, stowed the rover arm, and drove 15 meters (50 feet) to the "El Capitan" area. The drive was Opportunity’s longest yet and required the vehicle and planners to skirt the trench and avoid the lander.

The plan for sol 27, which will end at 12:57 a.m. Saturday, PST, is to first "supersize" the measurements of the "El Capitan" area with the panoramic camera, miniature thermal emission spectrometer, and microscopic imager. The mineralogy and geology teams have requested a minimum of three hours worth of "super resolution" and "super spectral" observations for the science instruments to get the most comprehensive coverage of this interesting site, which has varying textures and layers of dirt and rock.

After a short siesta in the early afternoon, Opportunity will drive 30 centimeters (12 inches) to sneak a bit closer to the rocks in "El Capitan" to get ready for the rock abrasion tool to do its work. After the drive, the Opportunity team plans to take a picture of the martian sky with the panoramic camera and miniature thermal emission spectrometer. If time permits, Opportunity will attempt to aim its cameras toward the heat shield in the far distance.

Over the weekend, Opportunity plans to find the perfect spot to use the abrasion tool and set it loose to grind away on "El Capitan," which will be the first use of the rock abrasion tool by Opportunity.

Daily Update - 2/19/04
Halfway Through
Spirit Status for sol 46

Sol 46, completed at 11:17 a.m. February 19, 2004 PST, marks the halfway point of Spirit's primary surface mission –--sols 2 through 91. Spirit began this momentous morning by doing some remote sensing of the crater rim and imaging the surrounding soil with the panoramic camera and miniature thermal emission spectrometer. After all this work, Spirit took a break with a nap lasting slightly more than an hour. After waking, Spirit continued its observations of the ground and sky with the miniature thermal emission spectrometer. At about 1:34 p.m. Mars Local Solar Time, Spirit found itself analyzing a patch of the atmosphere with the miniature thermal emission spectrometer at the same time that Mars Global Surveyor's thermal emission spectrometer was looking down through the same chunk of atmosphere. This concurrent observation will enable a more thorough understanding of martian atmospheric conditions.

Spirit's afternoon activities began at about 4:00 p.m. Mars Local Solar Time after the Mars Global Surveyor pass. Spirit was expected to take stereo microscopic images of the target "Trout" in Laguna Hollow. This is the first time the microscopic imager will take pictures at Gusev Crater without the Moessbauer instrument first touching the surface of the soil. The observation will provide pictures of undisturbed soil. After this, Spirit will perform a calibration activity by imaging a location in the sky with the microscopic imager and the navigation camera simultaneously.

Spirit's day will stretch into the night this sol with an overnight Moessbauer spectrometer integration. After a brief sleep, Spirit will wake at about 2:00 a.m. Mars Local Solar time on sol 47 to end the integration, collect the data and turn on the arm heaters. It will prepare for changing the tool from the Moessbauer to the alpha particle x-ray spectrometer, and begin observations with the new tool. Finally, the rover will leave the alpha particle x-ray spectrometer powered on and go back to sleep around 2:30 a.m. Mars Local Solar time.

On the morning of Sol 47, which will end at 11:57 a.m. February 20, 2004 PST, the plan is for Spirit to end the alpha particle x-ray observation and collect that data, and then perform some early mini-thermal emission spectrometer soil properties observations.

Daily Update - 2/19/04
Stutter Stepping to El Capitan
Opportunity Status for sol 25

On sol 25, which ended at 11:38 p.m. Wednesday, February 18, PST, Opportunity used the microscopic imager and alpha particle x-ray spectrometer to study the chemical makeup of the wall and floor area within the rover-made trench. Due to time constraints, Opportunity was unable to take a picture of the heat shield in the distance.

Sol 25's wake-up music was "Fascination" by Human League.

The plan for sol 26, which will end at 12:18 a.m. Friday, PST, is to back away from the trench, obtain one grand finale Moessbauer spectrometer reading of the trench, pick up and stow the rover arm, then turn and drive 9 meters (30 feet) to the El Capitan area. Opportunity will make a few intentional "stutter steps" on its way to El Capitan, stopping to take a few front hazard avoidance camera images and navigation camera images to plan for final approach and robotic arm activities.

Opportunity will stop a couple of meters (about 6 or 7 feet) short of El Capitan to take images with its panoramic camera and gather science measurements with its miniature thermal emission spectrometer. On sol 27, Opportunity will make a short, closer approach to El Capitan to poise itself to use the rock abrasion tool and other instruments on the rover arm.

Daily Update - 2/18/04
Spirit Does a "Wheel Wiggle"
Spirit Status for sol 45

Spirit began sol 45, ending at 11:17 a.m. February 18, 2004 PST, at its previous target, Halo, by conducting analysis with the alpha particle x-ray spectrometer, microscopic imager and Moessbauer spectrometer. Spirit also took panoramic camera images and miniature thermal emission spectrometer observations before its arm was stowed for the northeast drive toward a circular depression dubbed Laguna Hollow.

The first 19 meters of the drive toward Laguna Hollow was commanded using go-to waypoint commands with the hazard avoidance system turned off. This mode – which was used for the first time this sol – provides automatic heading correction during a blind drive. Some fine-tuning toward the target brought the total drive for this sol to 22.7 meters (74.5 feet).

After reaching Laguna Hollow, Spirit "wiggled" its wheels to disturb or scuff the fine dust-like soil at this location, which allows for more detailed observations with the instruments on the robotic arm. After adjusting position to put the disturbed soil in reach of the arm, Spirit backed up and completed a miniature thermal emission spectrometer scan of the new work area. Before the sol ended, Spirit made one more adjustment, putting it in perfect position to analyze the scuffed area beginning on sol 46

The plan for sol 46, which will end at 11:57 a.m., February 19, 2004 PST, is to conduct observations on Laguna Hollow with the instruments on the robotic arm, including some higher resolution analysis that will involve an overnight tool change.

Daily Update - 2/18/04
Peering into the Hole
Opportunity Status for sol 24

On sol 24, which ended at 10:59 p.m. Tuesday, PST, Opportunity used science instruments on its robotic arm to examine the hole it dug with its right front wheel on sol 23. The trench is about 50 centimeters (20 inches) long by 20 centimeters (8 inches) wide by 10 centimeters (4 inches) deep.

Sol 24's wake-up music was "Trench Town Rock" by Bob Marley.

The plan for sol 25, which will end at 11:38 p.m. Wednesday, PST, is to continue examining the walls and floor of the trench for clues about the history of Mars. Opportunity will also peek at its right front wheel with the panoramic camera to see what materials got stuck on the wheel from the trenching activity. Then, Opportunity will use the panoramic camera high on the rover’s mast to check out a former piece of itself -- the heat shield, which is sitting off in the distance. The heat shield protected the rover during cruise and during descent through the atmosphere on Jan. 4, 2004, PST.

Daily Update - 2/17/04
Can You Dig It?
Opportunity Status for sol 23

The Opportunity rover successfully dug an 8-centimeter (3.1 inch) trench on Mars using its right front "paw" or wheel on sol 23, which will end at 10:19 p.m. Monday, PST. Sol 23's wake-up music was "Spinning Wheel" by Blood, Sweat, and Tears, in honor of the right front wheel.

Opportunity also made observations with the navigation camera to help prepare for the drive to a target of interest within the outcrop named "El Capitan" later this week.

The plan for sol 24, which will end at 10:59 p.m. Tuesday, PST, is to thoroughly examine the freshly exposed layers of dirt and ground inside the rover-made hole. Opportunity will use its microscopic imager, Mössbauer spectrometer, and alpha particle X-ray spectrometer to take parallel science measurements and compare with those with measurements made on sol 22 during pre-trench activities.

Daily Update - 2/17/04
Spirit Passes 100-Meter Mark
Spirit Status for sol 44

Spirit controllers are calling sol 44 one of Spirit's most complicated and productive sols to date. Before commencing its record-breaking drive, Spirit began the sol, which ended at 10:38 a.m. February 17, 2004 PST, with an alpha particle x-ray spectrometer analysis of the soil target Ramp Flats. The analysis ran in parallel with a miniature thermal emission spectrometer observation of the martian sky. Spirit then continued observing "Ramp Flats" with the microscopic imager and Moessbauer spectrometer while operating the panoramic camera to get pictures of rocks in the distance called "V Ger" and "Broken Slate."

But this morning multi-tasking was only the beginning. After stowing the robotic arm, Spirit began a north-northeast drive that added a total of 21.6 meters (70.9 feet), bringing the rover's grand total to 108 meters (354 feet). That distance is about 6 meters (19.7 feet) more than Sojourner’s mission record, set in 1997. Controllers remarked that Spirit’s auto-navigation drives are consistently getting faster. These long drives are revealing new and interesting terrain, including more ridges, dunes, ripples and rocks with various appearances.

The plan for sol 45, which will end at 11:17 a.m. Feb. 18, 2004 PST, begins with analysis of a target at the current location, followed by a drive into a hollow between 15 meters (49 feet) and 18 meters (59 feet) away.

Daily Update - 2/16/04
Check before Digging
Opportunity Status for sol 22

Opportunity spent much of sol 22, which ended at 9:39 p.m. Sunday, PST, making a thorough "before" examination of the spot selected for digging a ditch the next sol.

Also, Opportunity completed upward-looking observations before, during and after Mars Global Surveyor flew overhead looking down. Opportunity and Global Surveyor have similar infrared sensing instruments: the miniature thermal emission spectrometer on the rover and the (full-size) thermal emission spectrometer on the orbiter. Coordinated observations of looking up through the atmosphere with one while looking down through the atmosphere with the other were designed to provide a more complete atmospheric profile than either could do alone.

Sol 22's wake-up music was "Invisible Touch" by Genesis. In preparation for digging, Opportunity examined the trenching site with its microscopic imager, its Moessbauer spectrometer and, overnight, its alpha particle X-ray spectrometer.

The plan for sol 23, which will end at 10:19 p.m. Monday, PST, is to dig a trench with alternating forward and backward spinning of Opportunity's right front wheel in order to see what's below the surface. Inspections of the resulting hole are planned for sol 24 and the morning of sol 25.

Daily Update - 2/16/04
Mega Drive
Spirit Status for sol 43

Spirit spent the wee morning hours of sol 43 gathering data about a wheel-track target with the Moessbauer spectrometer, then tucked its arm and drove. It used a two-session method engineers call a "mega drive" in order to make good progress toward the crater nicknamed "Bonneville." The first driving session covered 19 meters (62.3 feet) after long-running morning activities shortened the time for driving. After a rest, Spirit continued another 8.5 meters (27.9 feet) in the afternoon, resulting in a total drive of 27.5 meters (90.2 feet), a new one-sol record. Sol 43 ended at 9:58 a.m. Monday, PST. The remaining distance to "Bonneville" is about 245 meters (about 800 feet) from Spirit's new location.

For sol 44, which will end at 10:38 a.m. Tuesday, PST, controllers plan "touch-and-go" activities: deploying the arm on a target called "Ramp Flats" before continuing toward Bonneville.

Daily Update - 2/15/04
Dig this Place
Opportunity Status for sol 21

Opportunity completed its longest drive so far -- about 9 meters or 30 feet -- during its 21st sol on Mars, which ended at 9 p.m. Saturday, PST. The rover finished the drive with its first U-turn, arriving at a location selected for the mission's first trenching operation. Plans call for examining the hematite-rich surface of this location, called "Hematite Slope," during sol 22, then spinning one wheel to dig below the surface on sol 23.

Controllers at JPL chose "Send Me on My Way," by Rusted Root, and "Desert Drive," by Tangerine Dream, as Opportunity's wake-up music for sol 21. The rover worked a long day. It awoke earlier than usual for an early morning observation with its panoramic camera. It made additional observations from its new location just before finishing the drive, and again after finishing the last bit of the drive. Then it was woken after dark to make the mission's first nighttime observations with its infrared sensor, the miniature thermal emission spectrometer.

Daily Update - 2/15/04
A Wayside Stop, Then Back to Driving
Spirit Status for sol 42

Spirit used instruments on its robotic arm to examine an unusual-looking rock called "Mimi" during the rover's 42nd sol on Mars, which ended at 9:15 a.m. Sunday, PST. Scientists will be examining images and spectra to understand this rock's structure and composition and what those can tell about the environment in which the rock formed.

For sol 43, which will end at 9:58 a.m. Monday, PST, controllers have planned what they are calling a "mega drive": commanding a morning drive of about 25 meters (82 feet), then taking pictures of the scene ahead and letting the rover have a brief rest before using those mid-day pictures to guide an optional afternoon drive. Spirit is currently about 270 meters from the crater nicknamed "Bonneville," its mid-term destination.

Daily Update - 2/14/04
Spirit Gets the Drift
Spirit Status for sol 41

On its 41st sol, which ended at 8:39 a.m. Saturday, PST, Spirit examined the crest and trough of a drift formation encountered on its journey, then moved to a nearby rock.

The rover used its microscopic imager, Moessbauer spectrometer and alpha particle X-ray spectrometer on the drift material. Then it backed up about 10 centimeters (4 inches), turned, and advanced about the same distance to be in position for thoroughly examining the flaky rock called "Mimi" during sol 42, which will end at 9:18 a.m. Sunday, PST.

Plans call for resuming long daily drives on sol 43 toward the crater nicknamed "Bonneville" on the northeastern horizon.

Daily Update - 2/14/04
Rover Says 'No'
Opportunity Status for sol 20

During Opportunity's 20th sol on Mars, which ended at 8:20 p.m. Friday, PST, the rover told mission controllers "no." Opportunity received commands in the morning to use the microscopic imager at the end of its arm, but the onboard computer judged the requested arm movement to be unacceptable and refused the command.

This was the proper precaution for the rover to take. The arm maneuver had been tested with a simulation at JPL, and engineers subsequently worked on a solution to make the ground testing more accurately predict the rover computer's response to the particular arm-movement conditions involved.

However, with the arm left extended, rather than stowed, after the arm-movement command was refused, the rover also could not make the drive that had been planned for the sol. That drive, to a site selected for soil examination and trenching, was postponed until sol 21, which ends at 9:00 p.m. Saturday, PST.

Observations by the panoramic camera and miniature thermal emission spectrometer were completed successfully on sol 20. The sol's wake-up music was "I Like Dirt," by the Red Hot Chili Peppers, and "Pioneers of Mars," by Karen Linsley and Lloyd Landa.

Daily Update - 2/13/04

Spirit Status for sol 40

Spirit woke up to its 40th sol on Mars to the song "What a Wonderful World" by Louis Armstrong and then proceeded to have a wonderful sol which ended at 7:59 a.m. Friday, PST. After utilizing the miniature thermal emission spectrometer instrument on surrounding soil and completing some pre-drive imaging with the panoramic camera, Spirit proceeded 90 centimeters (2.95 feet) towards a collection of rocks called "Stone Council." The drive lasted less than five minutes. After completing the drive, Spirit imaged several rocks with the panoramic camera, and completed a mosaic of the area in front and to the left of itself.

On sol 41, which will end at 8:39 a.m. Saturday, PST, Spirit will be repositioned in front of the flaky rock called "Mimi" in preparation for placing its instrument deployment device on that rock during sol 42.

Daily Update - 2/12/04

Opportunity Status for sol 19

During its 19th sol on Mars, which ends at 7:41 p.m. Thursday, PST, Opportunity climbed to Waypoint Charlie, where it will complete its initial survey of the outcrop nicknamed "Opportunity Ledge."

The flight team at JPL chose 'Here I Go Again' by Whitesnake as Opportunity’s wake-up music.

The plan for sol 20, which will end at 8:20 p.m. Friday, PST, is to do a "touch and go," meaning Opportunity will touch the soil with its instrument arm around the outpost area Charlie, then stow the arm and drive. It will head for an area of soil that the rover's miniature thermal emission spectrometer indicates is rich in hematite. Over the following few sols, engineers intend to use one of Opportunity’s wheels to spin into the soil and “trench” a shallow hole so scientists can check what's below the surface early next week. Knowing more about the hematite distribution on Mars may help scientists characterize the past environment and determine whether that environment provided favorable conditions for life.

Scientists and engineers will pore over the data collected along Opportunity Ledge this week to target a return trip to the most interesting science locations along the outcrop later next week.

Daily Update - 2/12/04

Spirit Status for sol 39

During its 39th sol on Mars, which ended at 7:20 a.m. Thursday, PST, Spirit broke its own driving record. It adding 24.4 meters (80 feet) to its odometer while getting near an interesting set of rocks dubbed "Stone Council." The drive lasted 2 hours, 48 minutes. While navigating itself to avoid hazards, Spirit stopped when it recognized an obstacle, which was the group of rocks that was the day's intended destination.

The flight team at JPL chose Buster Poindexter's version of "Hit the Road Jack," as Spirit's wake-up music. The day's commands were uplinked during the cool morning hours via Spirit's low-gain antenna, to bypass a problem diagnosed the preceding day as shade slowing the warm-up of motors that move the high-gain antenna.

Before rolling, Spirit took images with its microscopic imager and panoramic camera from the site where it started the day.

The plan for sol 40, which will end at 7:59 a.m. Friday, PST, is a short drive forward then using instruments on the robotic arm to study soil at Stone Council.

Daily Update - 2/11/04

Opportunity Status for sol 18

Opportunity had a couple of little hiccups on sol 18, February 11, which ends at 7:01 p.m. Wednesday, PST. The wrist on the real rover arm would not point as far vertically as the engineering rover’s wrist did on Earth during a model test the night before. Because of this, the arm on Mars did not stow, and the rover did not move on to waypoint Charlie. The rover also automatically stopped use of the mast due to the fact that it believed a requested pointing position was in an area beyond its limits. Engineers solved both problems on sol 18. All systems are go for Opportunity to complete the tour of the outcrop by heading to outpost Charlie on sol 19, Thursday, February 12.

Daily Update - 2/11/04

Spirit Status for sol 38

On Spirit's sol 38, which ended at 6:40 a.m. Wednesday, PST, a failure to receive data during the morning high-gain communication window quickly led engineers to conclude that Spirit’s high-gain antenna was not pointed toward Earth. Spirit’s orientation after the previous sol's drive (45 degrees to the northeast) caused its camera mast to cast an early-morning shadow on the high-gain antenna’s elevation actuator. The cold conditions caused the actuator to stall and fail to point to Earth while being calibrated. The afternoon high-gain communication session performed flawlessly.

The afternoon communication window with Mars Odyssey provided previously acquired images of the rocks Adirondack and White Boat and a miniature thermal emission spectrometer observation of the depression drilled by the rock abrasion tool on Adirondack.

In coming sols Spirit will perform daily "touch and go" maneuvers, inspecting the soil surrounding it with the instruments on its arm, then continuing its drive toward the crater nicknamed "Bonneville."

Daily Update - 2/11/04

Spirit Status for sol 17

On its 17th sol on Mars, which ended at 6:21 p.m. Tuesday, Feb. 10, PST, Opportunity completed its study of the target area named Bravo. Opportunity is on a three-day tour of the outcrop, taking pictures and measurements to build what geologists call a "base map," which will help them decide what specific spots they want to target for more thorough investigation with their science instruments.

Daily Update - 2/10/04

Spirit Status for sol 37

On its 37th sol on Mars, which ended at 6 a.m. Tuesday, PST, Spirit broke the record for the farthest distance driven in one sol on Mars, traveling 21.2 meters (69.6 feet). Today's distance traveled shattered the Sojourner rover’s previous record of 7 meters (23 feet) in one sol.

In the coming sols, Spirit will continue its drive towards the crater nicknamed "Bonneville."

Daily Update - 2/9/04

Opportunity Status for sol 16

Opportunity appears to have experienced slips during 50 percent of a drive on sol 15, so for sol 16, engineers played a lighthearted wake-up call: Paul Simon's "Slip Sliding Away." Regardless of the loose soil, Opportunity made it across 4 meters (12 feet) today and is positioned to continue observing parts of the outcrop up close tomorrow. In coming sols, Opportunity will "shoot and scoot," meaning the rover will shoot pictures of the terrain and acquire new scientific measurements of the rocks, then scoot up, down, and across the inside of the crater.

Daily Update - 2/9/04

Spirit Status for sol 36

On sol 36, which ended at 5:21 a.m. Monday, PST, Spirit drove 6.37 meters (20.9 feet), using the onboard navigation software and hazard avoidance system for the first time on Mars. The drive, intended to test the traverse commands, was extremely precise, taking Spirit to its intended goal – the rock called White Boat. Before leaving the rock Adirondack, Spirit took images and collected miniature thermal emission spectrometer data from the hole ground by the rock abrasion tool.

In the coming sols, Spirit will continue its drive toward Bonneville Crater.

Daily Update - 2/8/04

Spirit Status for sol 35

NASA's Spirit examined the interior of a rock during Spirit's 35th sol on Mars, which ended at 4:41 a.m. Sunday, PST. Beginning late in the previous sol, Spirit took turns placing its Moessbauer spectrometer, alpha particle X-ray spectrometer and microscopic imager over the portion of the rock called Adirondack where Spirit's rock abrasion tool had cut away the rock's surface.

Spirit did not begin driving on sol 35, because a precautionary software setting to prevent driving was still in effect from the beginning of the anomaly two weeks ago. The rover is being commanded during sol 36, which ends at 5:21 a.m. Monday, PST, to back away from Adirondack, drive past the south side of the now-empty lander, and begin a trek northeast toward a crater nicknamed "Bonneville."

Daily Update - 2/8/04

Opportunity Status for sol 15

On Opportunity's 15th sol on Mars which ends at 5:02 p.m. Sunday, PST, the rover took microscopic images of a rock in the outcrop and nearby soil. The rock is called Stone Mountain (formerly called "Snout") and the target area for the microscope is called Robert E. The day's activities also include examination of Robert E with the alpha particle X-ray spectrometer and the Moessbauer spectrometer. Opportunity's panoramic camera and navigation camera were used to get pictures of the outcrop from the rover's current position.

In the coming sols, the plan is to move along the outcrop to examine other points along it.

Daily Update - 2/7/04

Spirit Status for sol 34

On Spirit's sol 34, which ended at 4:02 a.m. Saturday, PST, the rover's rock abrasion tool (RAT) successfully completed history's first grind into a rock on Mars. The rock of the day was Adirondack. Scientists and engineers were ecstatic when the afternoon communications relay from Mars Odyssey revealed a round and clean-surfaced depression.

Tomorrow, on sol 35, which ends at 4:41 a.m. Sunday, PST, Spirit is being told to inspect the newly exposed ancient rock material with her Moessbauer spectrometer, microscopic imager and alpha particle x-ray spectrometer before making a six-meter (20-foot) drive around the south side of the lander.

Current plans may keep Spirit in drive mode for the next few sols as she heads northeast towards a crater nicknamed "Bonneville."

Daily Update - 2/6/04

Opportunity Status for sol 13

On Opportunity's 13th sol on Mars, which ended at 3:43 p.m. Friday, the Mars Rover Opportunity was awakened by engineers at JPL playing the Beach Boys song, "Little Honda," with lyrics about various gear shifts. Images from the rover's rear hazard identification camera indicated that some fine-tuning was needed for a planned 1.5 meter drive to a target called "Snout" at the northeastern end of a rock outcrop in the inner wall of the landing-site crater. Adjustments were made, and new commands were sent to Opportunity. The rover is now tilted at nearly 13 degrees, pointing uphill. On its 14th sol, Opportunity will take microscopic images of the soil, then stow its arm and complete the short drive to Snout.

Daily Update - 2/6/04

Spirit Status for sol 33

NASA's Spirit was back and accomplishing another "first" in interplanetary science on Thursday: It brushed the dust off a rock to clean its surface for inspection.

On the first day of operations after they reformatted Spirit's flash memory, engineers confirmed that the flash memory was stable and available for data storage. Spirit was cleared to conduct the sol's science activities. The rock abrasion tool on the rover's robotic arm brushed a portion of the surface of the rock called Adirondack for five minutes. Spirit's panoramic camera and microscopic imager took pictures to show the effect of the brushing. The Mossbauer spectrometer and alpha particle X-ray spectrometer were used overnight on the brushed area.

The plan for Spirit for sol 34 is to use the rock abrasion tool again, this time to grind away the brushed portion of Adirondack's surface for examination of the rock's interior.