Today was a good exercise for the navigation system. Nomad drove itself for over two kilometers, using only three wheel drive. Things did not always go smoothly, but we learned quite a bit in the process.
Nomad drove for 645 meters in safeguarded mode, 2045 meters autonomously, and about 4.1 kilometers in total. The safeguarded driving was controlled by folks at the NASA Ames Research Center, including a "novice" driver who is actually a summer intern there. And the autonomous mode was used in several ways; to accumulate distance, to move in a particular direction, and to get to specific locations. The rest of the driving involved direct teleoperation from the Carnegie Science Center in Pittsburgh, where several team members from Carnegie Mellon University controlled it.
There were several interesting events during the autonomous driving time. Nomad got stuck in soft dirt at least four times today, due to a combination of circumstances; the navigation system was not calibrated to account for the missing motor, the laser system was not functioning, and there appears to be a slight delay in the communication between the navigation and the real time computers. Most of the time we were able to get unstuck by simply backing out of the soft dirt area, but once we had to break out the shovels and give Nomad some help. And at the end of the day we hoped to maneuver to a nice flat open area, so we opened the irises on the stereo navigation cameras to let Nomad drive us to a good spot. Doing so did allow us to drive until an hour later in the day than usual, but unfortunately it got to be too dark before we made it to the hoped-for location. And since it takes over 10 minutes to adjust the stereo irises, that procedure will not always be worthwhile.
To summarize the performance of the navigation system to date, Nomad has now been driven for 5766 meters in autonomous mode, and 4867 meters in safeguarded mode. We are still working at summarizing the logs from the first few weeks before we had more streamlined procedures in place (two of us spent several hours filtering many megabytes of data tonight), so please be patient; we look forward to providing running totals soon.