Jake Matijevic

End of Sol 19 State:

• The rover is in good health and all functionality is available.
• The sol 19 sequence concluded successfully. This sol was primarily devoted to measuring (with the rover instruments) the trench made by the rover on sol 18. The APXS, Moessbauer and CMI observations in the trench appear to have been executed. In the DTE downlink, short APXS and Moessbauer measurements outside the trench were returned and the data was determined to be ‘good’. In addition, a set of remote measurements of an area about a 1 meter forward from this trench were scheduled. The IPS and miniTES measurements performed revealed a carbonate signature. These measurements will affect the sol 20 planning. Also pancam measurements of the atmosphere were scheduled. This data and the non-critical portions of the in situ measurements were earmarked for the UHF link and were scheduled for earth arrival by sol 20.
• The resources available for sol 20 planning were energy of 691Whr, 70m DSN coverage, 13.38Mb of DTE and 49.1Mb of UHF downlink and 90min of rover operation.

Sequence Planning:

• With the long range planning objective of leaving this site and moving some 60+m to a target called Camelback, the team weighed the benefits of additional in situ measurement of the site 1 meter forward from the trench and making progress to the long range target. In a compromise, the team decided to perform a ‘trench, measure and drive’ sequence. As such, the rover would move forward, trench the terrain, move back and image both the new trench and the sol18/19 trench. Additional miniTES, IPS and atmospheric measurements were planned both before and after the trenching to complete the science objectives for sol20.
• It should be noted that this is the first time such an activity sequence was planned for FIDO. There were several discussions with the engineering team to assess the capability of the vehicle to perform such a sequence successfully without degrading the position knowledge of the vehicle and thus impacting the eventual drive. Characteristics of the terrain (sparse obstacle field, flat ground) and position updates after trenching were the solution to the position degradation issue.
• The mission directive of ‘not more than 3m of driving without hazard avoidance’ was satisfied with difficulty in the sequence through the inclusion of a ‘turn in place 90deg’ at the end of the ‘forward motion, trench and backward motion’ sequence, allowing the mast mounted instruments views of both trenching sites.

Sequence Development:

• There was concern that the sequence plan from the science team could not be completed and still allow for a drive away from the trenching site. Initial resource assessments of the top few observation objectives indicated that driving of less than 20m could be accomplished after these observation were performed. This became the working plan through the integrated sequence team session.
• Waypoints were chosen to avoid loose soil/rock impediments and the few rock obstacles in the vicinity of the rover. Intermediate waypoints were chosen to allow ‘turns in place’ on flat ground toward the eventual objective. A total distance of about 15m was the result of the planned drive.

As the sequence was completed the activities accommodated were:

• atmospheric sky survey (pancam imaging)
• miniTES spot measurements (area of new trenching)
• moon photometry (last chance for this measurement in the field test)
• drive forward 1.4m
• trench approximately 1 wheel revolution
• drive backward approximately 1.5m
• turn in place 90deg
• pancam image the two trenches
• turn back toward waypoints
• drive to toward Camelback in three waypoints

The sequence was uplinked with about 15min to spare.

Sol 21 Considerations:

• The DTE downlink was filled with Navcam and Hazcam images at the completion of the drive. These images were sized sufficient to enable planning for a subsequent drive on sol21.
• The UHF downlink was consumed by a backlog of past measurements accumulated during the in situ activities of sol 18 and 19. The data collected on sol 20 will fill approximately 30Mb of the UHF downlink on sol 21. Hence, the sol 21 planner should be cognizant that there is a limited capability for science observations in the next couple of sols if the objective of driving to Camelback is to be achieved.
• Driving must be completed by sol24, which is a low (4Mb) DTE sol suited for in situ measurements. The field test ends with sol26.

Final considerations:

• The trenching and measurements of sol 18 and sol 19 enabled the team to achieve the third of 3 locations and completion of a trench objective.for mission success. If the drive of sol 20 is successful the integrated distance will increase from 143m to 158m with the mission success objective of 200m. A panoramic image of the field test site has been obtained.
• The science team is cognizant of the objective of completing the drive to Camelback, both for the purpose of completing the mission success objective and getting to an interesting new location for what appears to be an ‘end of field test’ strategic position. At such a location, the remainder of the field test would be dedicated to remote observations and in situ measurements, driven by time and downlink limitations.

Closing comments:

• My thanks to the FIDO science and engineering team which helped make my experience as mission manager a pleasant one. I was impressed with the organization and discipline of this team which has improved since the last field test. I am looking forward to this team carrying its experience into the ORTs and eventual mission operation for MER. Good luck for the remainder of the test.

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