FLIGHT
SOL 67 END-OF-DAY DOWNLINK STATUS REPORT

Last updated: 10 Sep 1997, 17:00 PDT, Data Controller: Allen R. Sirota

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


Stumped at Stimpy




SUMMARY REPORT

Sequence 56610B:

Sequence 56710C:



RETRANSMIT REQUESTS




SEQUENCE PLANNING RECOMMENDATIONS

Operational Constraints (for Sol 68 Sequence):

  1. New or changed recommendations:
    • Suggest retract APXS, then move forward 3 cm (to get off Stimpy), then deploy APXS until contact
    • Disable Y accelerometer for Sol 68 moves
    • Make sure modem reheat is off before LMRE is turned off; Rover was very hot at the end of Sol 66 (but don't know for sure if this was the problem)

Engineering Requests:
  1. Perform gyro/encoder turn-in-place test when feasible
  2. HAVE S0050 IMAGES TAKEN DURING WAYPOINT COMMANDS ... ESPECIALLY WHEN DRIVING OVER ROUGH TERRAIN!
  3. S0050 images at Low-Compression (3:1).
  4. (DESIRE) Take rover images as early in the morning as possible to reduce dark noise current.
  5. (DESIRE) Leave rover on until 15:45 LST to collect late afternoon thermal data, perform health check just before shutdown.
  6. (DESIRE) Perform Wheelie before start of Traverse and Soil Experiment at end of Sol's traverse when practical

Operational Constraints (General):

  1. No Battery Mission
    • Do not perform APXS (and 'hold_comm') beyond 14:30 LST
    • Do not turn on APXS when heating expected as limiter reaction time may not be fast enough to prevent loadshed.
    • Limit Imaging to 09:30 to 14:30.
    • Limit Driving to 10:00 to 14:30.
    • Do not use relative waits while in hold_comm
    • Try to complete major operations by 14:30 MLST
    • When shutting down for the night command the vehicle to wakeup at 07:30 LST the next morning. This is important from a telemetry standpoint in that it will limit the degree to which our telemetry plots are scrambled.
    • The ONLY time the vehicle should be "shutdown" is at the end of the day.
    • DO NOT perform Level 3 Health Checks prior to 9:00 or after 15:00.
    • Disable battery usage for all devices.
  2. It is recommended that prior to executing a Deploy APXS command when the APXS may already be in contact the APXS should first be retracted by about 10 degrees to make up for the inherent 8-10 degrees of motion that will always occur during the beginning of the APXS Deploy command.
  3. Make sure sequence has as many days of runout as possible (analogous to the design of the 54910B sequence.
  4. Accelerometers
    • DISABLE the Y accelerometer during moves and waypoints at risk level 1
    • CAN DISABLE the Y accelerometer during moves at risk level 2 ONLY IF planned path appears 'safe'; otherwise ENABLE Y accelerometer.
    • ALWAYS ENABLE Y accel for waypoints at risk level 2
    • Leave X accelerometer ENABLED
    • Leave Z accelerometer DISABLED
  5. Heating
    • Do not heat and run APXS at the same time
    • Set modem Heat and Reheat parameters both to "0" prior to shutting down for the night if LMRE is NOT going to be turned on prior to expected rover solar wakeup of ~7:15 LST. Reset them back to normal values on the morning of "runout" Sols.
    • Set Modem Heat to 15 minutes normall, 0 minutes if sequence to be queued after 12:00 LST
    • Set Modem Reheat to 5 minutes and maximum modem reheat temperature 30 deg
    • Enable Modem Heat and Reheat only when LMRE is ON.
    • Perform WEB heating on days of low activity (i.e. no traverses) and Runouts.
    • Use Web_Heat_B parameter with Max temp of +30C from 12:30 to 15:00 when WEB heating.
    • Set Web_Heat_B parameter to -30C (-273) when not heating.
    • Always leave Web_Heat_A parameter at +40C (1197).
    • Limit image transfer after 1:00 LST (to prevent overheating)
  6. Traverses
    • Do NOT move with Bogie potentiometers disabled.
    • Enable hazard avoidance using sensors, contacts, and laser proximity, and perform each waypoint command only once.
    • Limit each "Move Command" distance to 0.5 meter or less to enable gyro to be recalibrated and thereby reduce the amount of drift.
    • Before beginning traverses, should back up a little (~ 10 cm) to enable lasers to detect hazards which may be very close to the front of the rover. UNMASK contact sensors for this move. May want to then move forward ~ 1 cm, with contact sensors MASKED to remove any contact that may have been made during the previous backward move. Then UNMASK all contact sensors and plan subsequent waypoints.
    • When performing long waypoint traverses with "thread-the-needle" enabled like that performed on Sol 35, break the waypoints up such that the last segment is performed with "thread-the-needle" disabled. This way the vehicle will make sure (most likely) that it ends up in a location in which it can safely turn in place without climbing on nearby obstacles. If the vehicle stops because it can not find a path as wide as the turn circle, subsequent turn commands will be skipped ... and we may be able to avoid the situation we ran into on Sol 36.
  7. Health Checks
    • Change HC after LoadShed Reset to Level 2 instead of Level 3.
    • DO NOT perform Level 3 Health Checks prior to 9:00 or after 15:00.
    • 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.
    • Always command a Level 2 Health Check before shutdown.
    • Perform level 2 health check at the end of every traverse command
    • If possible, health checks should not be skipped as a result of traversable hazards.
  8. Mask all errors (except INVALID CMD) immediately prior to "Read Mem" of persistent state table. Unmask accordingly immediately afterwards.
  9. Perform Read Memory just before last downlink session
  10. Perform Sync Clock just prior to EOD shudown (or LMRE off) after Clear Errors.
  11. DISABLE RF Wheel Temperature Sensor
  12. Insert longer wait (10 seconds) between APXS cycle start command and APXS turn-off command (turn off devices)
  13. 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 (EOD Sol 67):

VEHICLE STATE: (AS OF COMMAND: 0, Auto Level 2 Health Check during Wait 17077
SCET: 9/10/97 21:14, MLST: Sol 67 11:34 )

BATTERY STATE/USAGE(AS OF EOD SOL 67)

SUBSYSTEM STATUS (AS OF EOD SOL 67):



TRAVERSE HAZARDS (DETECTED)



TELEMETRY VOLUME



SUBSYSTEM REPORTS

NAVIGATION PERFORMANCE:

THERMAL PERFORMANCE:

TELECOM PERFORMANCE 

Telecom system performance was much better this Sol than for Sol66. According to rver navigation data
 the rover is 1.275 meters closer radially to the lander on Sol 67 than on Sol 66. This is about two UHF RF wavelengths,
 which would definitely change the resulting scattering and multi-path effects.  This can account for the improvement
 in telecom performance. There are no telecom operational constraints for future rover operations.

The end-of-sol communication system performance for the downlink was as follows:

SOL 67 DOWNLINK TELECOM STATISTICS
Rov Radio Temp Low =    -23.1
Rov Radio Temp High =   25.7
Rov Radio Temp Avg =    12.0
LMRE Radio Temp Low =   -11.2
LMRE Radio Temp High =  19.6
LMRE Radio Temp Avg =   11.5
Rx Current Low =        43.5
Rx Current High =       49.3
Rx Current Avg =        47.7
Tx Current Low =        156.6
Tx Current High =       156.6
Tx Current Avg =        156.6
LMRE Good Frames =      1401
LMRE Garbled Frames =   398
Avg LMRE Link Quality%= 77.9
TX_CH_FRAMES =  1570
RX_CH_FRAMES =  1491
Total Frame Resends =   79
Avg Rover Link Quality%=        95.0
COM:Bad CRC Errors =    18
COM:Timeout Errors =    53209
COM:Rx Abort Errors =   760
COM:No Sync Errors =    4
COM:RX Com Errors =     39245


In planning the sequence for Sol 68 and beyond, the revised modem heating strategyused should be followed:
For rover wakeups on solar power, modem heating is only needed if communications i needed  in the morning.
In this situation set modem heating to 0 and reheat to 300 seconds. Also, if there are afternoon only downlink
sessions, then no modem heating is required after wakeup on solar. The rover modem should be commanded in the
next-day runout sequence to perform a 300 second modem reheat at wakeup. Later in the day, modem reheating should
be triggered by an excessive number of frame retries on the rover-to-lander link, and the reheating should continue
for five minutes or until the rover modem reaches +30 C.  However, if the LMRE radio is off, then the reheat to
get to +30C is not needed. This requires some coordination of timing between the LMRE ON times and the rover transmissions.
The sequence planners should consider the uncertainty in event completion times introduced by any required modem reheating cycles.

MOBILITY PERFORMANCE: 

Report pending

POWER PERFORMANCE: 

With the exception of the battery, which was depleted on SOL 56, the remaindeof the Power Subsystem is in good health.  The power subsystem continues to
operate only on solar power.  There were no new operational problems noted inthe SOL 67 telemetry.


TELEMETRY PROCESSING ANOMALIES


PRESS RELEASE

TBD

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.