Sol 188 was devoted to finishing an examination of a target patch called "Tuktoyuktuk" where the rover's rock abrasion tool had ground the surface coating off of a rock called "Inuvik." Opportunity then drove partly up-slope and partly cross-slope as both a mobility test and the start of a traverse to the next target. It slipped down-slope about as much as expected, a good result. The rover's current terrain consists of rocky plates lightly covered with sand and soil, plus some deeper sandy patches between the plates. The sandy patches result in more slip and sometimes cause the vehicle to yaw a little (as more slip on one side of the vehicle than the other causes it to turn). The overall tilt of the rover is about 18 degrees.
On sol 189 the rover drove about 4 meters (13 feet) eastward across the inner slope of the crater. The drive went well despite substantial down-slope slip. Slippage averaged about 33 percent, with a peak of about 56 percent on one half-meter (1.6-foot) drive segment, but the rover team expected that and compensated in advance for it. The team then asked the rover to conduct a series of turns in place during the communications relay pass with the Mars Odyssey orbiter to optimize the communications link. The idea was to keep Odyssey in the sweet spot of the rover's ultra-high-frequency antenna pattern as the orbiter swept across the sky. The total data return was about 135 megabits. The best possible return predicted by models if the rover had just sat in one orientation was about 115 megabits.
The next target the scientists would like the rover to approach, "Axel Heiberg," is a rocky outcrop about 18 meters (59 feet) away to the east and a bit deeper in the crater.