Opportunity is on the west rim of Endeavour Crater heading towards 'Marathon Valley,' a location assumed to have abundant clay minerals only about a half-mile (800 meters) to the south.

With the continuing Flash memory problems on the rover, the project has chosen to operate the rover without using the non-volatile Flash storage system and instead rely on the volatile random access memory (RAM) for temporary storage of telemetry, or rover data.

Longer term, the project will implement a strategy to mask off the troubled sector of Flash and resume using the remainder of the Flash file system in normal operations.

Using RAM memory for data storage, Opportunity drove on Sols 3868, 3870 and 3873 (Dec. 10, 12 and 16, 2014), totaling over 361 feet (110 meters).

Engineers collected drive direction imagery and atmospheric observations on the same sol of each drive. Drivers are developing sets of multi-sol plans, some containing drives, to carry the rover's activities through the coming holidays.

As of Sol 3874 (Dec. 17, 2014), the solar array energy production was 494 watt-hours, an atmospheric opacity (Tau) of 1.189 and a solar array dust factor of 0.646.

Total odometry is 25.73 miles (41.42 kilometers).