Opportunity is on the west rim of Endeavour Crater heading towards "Marathon Valley," a putative location for abundant clay minerals. The rover is headed to a near-term target, a small crater named "Ulysses."

The rover is moving closer to Ulysses to get a peek inside. On Sol 3787 (Sept. 18, 2014), Opportunity drove a little over 44 feet (13.5 meters) in rocky terrain, requiring the use of Visual Odometry to safely navigate.

On Sol 3789 (Sept. 20, 2014), the rover moved closer to the rim of Ulysses, but the drive stopped after 15 feet (4.6 meters) because Visual Odometry was not tracking on the last steps.

An evening Alpha Particle X-ray Spectrometer measurement of atmospheric argon was performed on Sol 3790 (Sept. 21, 2014). The rover continued closer to Ulysses on the next sol with a 13-feet (4-meter) bump. High slip prevented the rover from completing the turn for communication at the end of the drive.

Recently, there were more Flash-related events. Two more "amnesia" events occurred on the evenings of Sols 3786 and 3789 (Sept. 17 and Sept. 20, 2014). And two Flash write errors to Bank 7 occurred on Sols 3791 and 3792 (Sept. 22 and Sept. 23, 2014).

All these events were benign and did not impact the rover's operation. The project continues to investigate. Otherwise, Opportunity continues in good health.

As of Sol 3792 (Sept. 23, 2014), the solar array energy production was 639 watt-hours with an atmospheric opacity (Tau) of 0.889 and a solar array dust factor of 0.740.

Total odometry is 25.34 (40.77 kilometers).