FLIGHT
SOL 23 END-OF-DAY DOWNLINK STATUS REPORT

Last updated: 27 July 1997, 13:00 PST, Data Controller: Allen Sirota

Summary Report
Retransmit Requests
Sequence Planning Recommendations & Constraints
Sequence Execution Status
Telemetry Volume
Traverse Hazards (Detected)
Subsystem Reports
Telemetry Processing Anomalies
Press Release


Rover headed for open territory



SUMMARY REPORT

Sequence 52220B: Sequence 52310D:

RETRANSMIT REQUESTS

NO RETRANSMITS WERE PERFORMED ON SOL 23.




SEQUENCE PLANNING RECOMMENDATIONS
Proceed with nominal sequence planning Operational Constraints (Sol 22 Sequence):
  1. Reset APXS_DLIM before any traverse commands.
  2. Leave X accelerometer ENABLED
  3. DISABLE both the Y and Z accelerometers during all waypoints and moves to be performed on Sol 24 assuming terrain is similar to that traveled on Sol21.
  4. Recommend Risk Level 1, Laser drop out 3.
Engineering Requests:
  1. Waypoint Navigation:
    • Continue to perform waypoint commands.
    • Take seperate S0055 images after each individual waypoint command.
    • Take S0050 (Rover Movie) of each individual waypoint command.
  2. Take pre and post S0050 images at Low-Compression (3:1).
  3. (DESIRE) Take rover images as early in the morning as possible to reduce dark noise current.
  4. (DESIRE) Leave rover on until 15:45 LST to collect late afternoon thermal data, perform health check just before shutdown.
Operational Constraints (General):
  1. If need to perform Level 3 health checks between Sol n, 20:00 LST and Sol n+1,8:00 LST, disable lasers (i.e., never power) to prevent them from being turned on. Re-enable afterwards.
  2. Heat modem for 5 minutes prior to morning transfer of images.
  3. Terminate heating at 15:00
  4. Disable auto shutdown
  5. Set Modem Heat to 15 minutes; 10 minutes if following a night-time APXS)
  6. Set Modem Reheat to 5 minutes.
  7. Set alarm based wakeup to 08:00 LST
  8. Perform Read Memory just before last downlink session
  9. DISABLE RF Wheel Temperature Sensor
  10. DISABLE Z accelerometer.
  11. Perform Time Sync just prior to EOD shudown.
  12. Always command a Level 2 Health Check before shutdown.
  13. Perform level 2 health check at the end of every traverse command
  14. Limit image transfer after 1:00 LST (to prevent overheating)
  15. Limit each "Move Command" distance to 1 meter or less to enable gyro to be recalibrated and thereby reduce the amount of drift.
  16. Insert longer wait (10 seconds) between APXS cycle start command and APXS turn-off command (turn off devices)
  17. Perform WEB heating on days of low activity (i.e. no traverses) with no night-time APXS operations, and Runouts from 13:00 (noon) to 15:00 MLST.
  18. Use Web_Heat_B parameter with Max temp of 30C.
  19. Future soil mechanics experiments in suspected hard material should have 6 spins of 500 counts rather than 4.


SEQUENCE EXECUTION STATUS & VEHICLE STATE

SEQUENCE EXECUTION STATUS:

VEHICLE STATE: (AS OF COMMAND: 23119, Clear SCET: 7/27/97 19:21 )

BATTERY STATE/USAGE

SUBSYSTEM STATUS:



TRAVERSE HAZARDS (DETECTED)



TELEMETRY VOLUME



SUBSYSTEM REPORTS

NAVIGATION PERFORMANCE:

THERMAL PERFORMANCE: 

The CPU and PWR boards both exceeded 40 degrees; 40.1 and 40.6 respectfully.


Sol 22 pm Max recorded: 28.6 WEB, 34.0 CPU, 11.7 MAE
Sol 23 am Min recorded: -22.7 WEB, -16.4 CPU, -76.7 MAE
Good max and min temperatures were not recorded.
Recommendations:
Future runouts and low activity days should have battery heating from
13:00 to 15:00 LST only.

TELECOM STATISTICS FOR SOL23 

The Rover Telecom Subsystem performed nominally during operations for SOL23.
The Rover radio modem and LMRE radio modem can be used without restriction
for upcoming sequences.

STATISTICS

On this first day of the rover's circumnavigation of the lander, the rover
passed through the most extensive null-zone in the lander antenna pattern,
which may explain the region of approximately 30% link quality at about noon
MLST.

Rover temperature ranged from  -15 C at wakeup to +38 C at end of day.

Rover receive and transmit currents were 46.4 and 162.4 mA respectively.

Overall Lander side frame counts indicate a link quality of 56.7% for 2090
frames.

Rover side link performance is at 99.3% for 7772 frames.

RECOMMENDATIONS

The standard recommendation of heating the rover modem for 600 sec
(900 if no overnight APXS), reheating 300 secs prior to wakeup should
be continued (with a target wakeup temperature of -10 C).

Heating the rover modem an additional 300 seconds immediately
prior to large-packet image transfers is also recommended.

Currently, there is no request to enable LMRE heating prior to wakeup.

MOBILITY PERFORMANCE: 

The activities today included three "waypoint" commands, a soil experiment
and a WAE experiment. The traverse covered 7 meters and was very
successful.

The max motor current registered today was 42.9mA which occurred at the time
of getting off the souffle rock early this am. Most currents measured were in
the 20-30mA range. The Y accelerometer had one spike of -.32g at a time
when the vehicle was stationary.

The time tag on the soil experiment jumped a day...very strange.

The RF temperature sensor is bad and has been forced failed.




Daily Odometry:  7.081 m
Total Odometry: 33.094 m
Average Wheel Odom: 50.186 m

Recommendations:
No new recommendations.

POWER PERFORMANCE: 

Based upon the data returned in the health checks returned in SOL 23,
the Power Subsystem is in good health with no operational problems noted.
The late in the day moves on SOL 22 were expected to cause the power level
to be greater than the solar panel could support.  However, there is no
indication that the batteries were called upon to suppliment the solar panel
during the moves.  This is probably due to shading of the MAE short circuit
current cell which is used in the solar panel power capability prediction.
Based upon this, the predicted solar panel power available may be conservative.


TELEMETRY PROCESSING ANOMALIES


PRESS RELEASE

The Sojourner took off for open ground after attempting to acquire an APXS spectrum on souffle

Web Page Authors: Henry W. Stone and Allen.R.Sirota

All information on this site, including text and images describing the Rover is copyright © 1997, Jet Propulsion Laboratory, California Institute of Technology and the National Aeronautics and Space Administration.