Spirit's battery levels are slowly edging upward, thanks to a slight decrease in atmospheric dust (Tau) and a gradual increase in sunlight as winter gives way to spring.

Early in the week, Spirit spent two Martian days carrying out contingency plans following a temporary delay in data transmission from Earth. Spirit implemented the so-called "runout" portion of an earlier master sequence on sols 1628 and 1629 (Aug. 1-2, 2008). Subsequent relays of new instructions from Earth on sols 1629 and 1632 (Aug. 2 and Aug. 5, 2008) went off without a hitch.

Spirit remains healthy, with all subsystems performing as expected as of sol 1630 (Aug. 3, 2008).

In addition to using the panoramic camera to make daily measurements of dust-related changes in atmospheric clarity, Spirit completed the following activities:

Sol 1628 (Aug. 1, 2008): Spirit implemented the runout portion of the master sequence of commands already on board the rover.

Sol 1629: Upon awakening, Spirit continued to implement the runout portion of the master sequence sent earlier. Spirit then received new instructions directly from Earth via the rover's high-gain antenna.

Sol 1630: Spirit acquired column 13 of the "Bonestell panorama" using all 13 color filters of the panoramic camera. The rover relayed fresh data from Mars at UHF radio frequencies to NASA's Odyssey orbiter to be transmitted to Earth.

Sol 1631: Spirit recharged the batteries.

Sol 1632: Spirit received new instructions from Earth via the rover's high-gain antenna.

Sol 1633: Spirit acquired six freeze frames for a time-lapse movie in search of Martian clouds using the navigation camera. The rover took spot images of the sky for calibration purposes with the panoramic camera and monitored dust on the panoramic-camera mast assembly.

Sol 1634 (Aug. 7, 2008): Spirit transmitted fresh data to Odyssey to be relayed to Earth.

As of sol 1634 (Aug. 7, 2008), Spirit’s total odometry remained at 7,528.0 meters (4.7 miles).

"Victoria Crater" continues to challenge Mars rover drivers as they try to find a location where Opportunity can do scientific studies of rocks near the "Cape Verde" cliff face. They have been trying to drive the rover to a location nicknamed “Nevada” after a rock shaped somewhat like the state of Nevada. Getting there, however, has been challenging.

After attempting unsuccessfully to drive the rover on steep slopes that caused the wheels to slip, they are aiming for a new location. They have identified a large flagstone to the left of Nevada that offers solid footing and a low amount of tilt. They hope to drive the rover there, re-evaluate the terrain, and re-assess whether it is possible to reach Nevada.

They are also working on a campaign to have Opportunity document different styles of weathering on local rocks. The rover, meanwhile, continues to measure argon gas in the Martian atmosphere and make other atmospheric observations.

Opportunity remains healthy, with all subsystems performing as expected as of the rover's 1,599th Martian day, or sol (July 23, 2008), of exploration. Solar energy on the vehicle has been averaging just under 360 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).

Sol-by-sol summary

In addition to making daily assessments of atmospheric dust based on the darkness of the sky as viewed by the panoramic camera and relaying data to NASA's Odyssey orbiter for transmission to Earth, Opportunity completed the following activities:

Sol 1593 (July 17, 2008): Opportunity drove and took post-drive images of the surrounding terrain with the hazard-avoidance and navigation cameras. After communicating with Odyssey, the rover went into a deep sleep.

Sol 1594: Opportunity spent 4 hours and 15 minutes integrating measurements of atmospheric argon with the alpha-particle X-ray spectrometer. The rover went into a mini-deep sleep.

Sol 1595: Opportunity took full-color images, using all 13 filters of the panoramic camera, of rock exposures dubbed "Mawson," "Murchison," "Mackay," and "King." After sending data to to Odyssey, the rover went into a deep sleep.

Sol 1596: Opportunity monitored dust on the rover mast, drove, and took post-drive images with the hazard-avoidance and navigation cameras. After the day's activities, the rover went into a deep sleep.

Sol 1597: Opportunity took full-color images, using all 13 color filters of the panoramic camera, of rock exposures nicknamed "Playfair" and "Eugene_Smith." After relaying data to Earth, Opportunity went into a deep sleep.

Sol 1598: In the morning, Opportunity took four freeze-frame images with the navigation camera for a movie to document potential clouds. Following a short drive, Opportunity took images with the hazard-avoidance and navigation cameras. After sending data to Odyssey, the rover measured atmospheric argon with the alpha-particle X-ray spectrometer.

Sol 1599 (July 23, 2008): Opportunity took more full-color, panoramic-camera images of Mackay and Mawson. Plans for the following morning called for Opportunity to take full-color images of Murchison.

Odometry

As of sol 1598 (July 22, 2008), Opportunity’s total odometry was 11,725.96 meters (7.29 miles).