I don't want my wheel on
that stinking rock!

Sequence 55310D:

• Received telemetry for all commands not received yesterday (i.e., starting at 3100) up through the "end of nominal sequence execution".
• APXS spectra's of Half Dome were skipped due to lack of contact with Half Dome as intended.
• No errors reported.
• Y Accel readings during MAE experiments 3104 and 3114 were at "pegged" at 0.357g ... essentially the same value as was recorded by the most recent Level 3 Health check prior to these two commands. Its awfully suspecious that the value corresponds to 3/8 g (i.e., 1 Mars g). I've got to wonder whether there is some way electronically or via software that we are actually reading the Z accel.
• Y Accel readings returned to normal following the Shutdown at the end of the day (i.e., the next morning). Still don't have a clear explanation for the failure mode. Note that the accels are turned on and off during each motion command (i.e, turns, moves, soil, waypoint, etc), Level 3 and above Health Checks, and other commands which require Accel readings. The accels DO NOT remain on throughout the day.
• Vehicle remained healthy.
• Sequence aborted by Sequence 55410C as planned.

• Sequence queued on schedule
• The Turn command errored out shortly after is started due to detection of a differential hazard. Note that just prior to the Turn the differential was just below the risk level 2 hazard threshold.
• APXS Deploy command failed almost immediately after detecting the same differential hazard condition.
• Conditional nature of sequence will cause the subsequent acquisition of APXS spectra to be skipped to conserve on battery.
• EOD images show that the Left Middle wheel is in the air and the left Bogie is at its physical limit. This condition could easily have been caused by slippage on the Left Rear Wheel or abnormally high current draw by the Left Rear Wheel indicating that it was having trouble getting up onto Half Dome. Telemetry data appears to support the former. The Left Rear Wheel current remained in the nominal range but did fluctuate up and down. All four corner wheels rotated by essentially the same amount.
• All 3 Accelerometers appear to be working fine with NO anomalous readings recorded ... the mystery continues!
• Solar panel output is significantly better than predictions (by about 2.5 watts).
• Vehicle remains healthy.

• Lander shutdown at night - No retransmits possible
• Standing Request to retransmit most critical data (APID's 7, 12) 30 minutes into planned downlinks EVERY Sol due to loss of retransmit capability in Lander

Modify nominal sequence for Sol 55.

• Apparently the rover driver(s) determined that the rover could be safely turned in place on Sol 54 without running the risk of having the Right Rear wheel fall into the "crevice" between Shark and Half Dome. Assuming this is the case we suggest that the Turn in place be completed with the differential sensor disabled. Once the Left Rear wheel starts to climb onto Half Dome the differential will return to its center position.

1. New or changed recommendations:
   
   • Commanded Health checks performed during the day should be performed at Level 3 so that we can get more Accel performance data. Level 2 health checks don't turn on the accels, they only report old values.

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

1. Make sure sequence has as many days of runout as possible (analogous to the design of the 54910B sequence.
2. Perform EOD Sync Clock AFTER Clear Errors so it is not skipped.
3. Change morning wakeup time (via night shutdown) to 8:00 LTST.
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
   • 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. Disable battery usage for modem heating on runout mornings.
   • Set Modem Heat to 15 minutes normally; 10 minutes if following a night-time APXS, 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) with no night-time APXS operations and Runouts.
   • Use Web_Heat_B parameter with Max temp of +30C from 13:00 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
   • 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 auto shutdown
12. DISABLE RF Wheel Temperature Sensor
13. Insert longer wait (10 seconds) between APXS cycle start command and APXS turn-off command (turn off devices) .
14. Future soil mechanics experiments in suspected hard material should have 6 spins of 500 counts rather than 4.

SEQUENCE EXECUTION STATUS (EOD Sol 54):

Execution:	Off Nominal, APXS deploy unsuccessful
State:	Nominal, Moderate roll and pitch
	Left Middle Wheel off ground
	Left bogie at mechanical stop
Wakeup:	Solar Power, SOL 54 08:01 LTST per Rover but actually 07:54:09
Crit Errors:	Turn failed due to differential hazard
	APXS deploy failed due to diff hazard
Executing sequence 55410C

VEHICLE STATE: (AS OF COMMAND: 4076 Set Parameter
SCET: 8/28/97 14:08, MLST: Sol 54 13:00 )

Mission Phase:	Primary
Mode:	Executing
Config:	Moderate roll and pitch
	Left Middle Wheel off ground
	Left bogie at mechanical stop
	Differential beyond Level 2 hazard
Power:	Nominal
Device Status:	Gyro force failed
	Z accel force failed
	RFW temp. force failed
	APXS set to not be powered
Temp (Internal):	Nominal
Temp (External):	Nominal
Temp:(Modem):	Nominal

   Parameter     Initial      Final    IMP EOD    Parameter    Initial     Final
---------------------------------------------------------------------------------
X Position (m)   -4.970      -4.934       ?      LBogie (deg)  +19.36     +35.68
Y Position (m)   -3.816      -3.718       ?      Rbogie (deg)  -18.08     -22.16
Heading   (deg)   +88.5       +70.6       ?      Diff   (deg)   +9.52     +16.56

Pitch    (deg)    +13.1      +15.5     (+ Pitch -> Front down)
Roll     (deg)    +18.0      + 7.1     (+ Roll  -> Roll to Starboard)

ADM Pos  (deg)    -97.28      -10.24     (slightly deployed)

LFS      (deg)     +1.9       -43.5              RFS    (deg)   -0.6     +42.2
LRS      (deg)     +0.6        46.7              RRS    (deg)   -1.3     -48.6
--------------------------------------------------------------------------------

BATTERY STATE/USAGE(AS OF EOD SOL 54)

              Total         Battery   Remaining (Amp*hrs)
Category    Allocation      Initial    Final    *Predicted
--------------------------------------------------------------
Operations      10           2.552     2.462      2.362
Science         10           4.450     4.408      4.408
Technology      10           7.260     7.250      7.250
--------------------------------------------------------------
Total           30          14.262    14.120     14.020

*   at completion of sequence 55410C.

	ADM			Bumper		Solar
	UL	UR	B	RB	LB	LR	RR	RF	LF
Mask	1	1	1	1	1	1	1	1	1
State	0	0	0	0	0	0	0	0	0

	ERROR FLAGS
	Skip	GenFail	InvalidCmd	WEB_Hot	NoPwr	NonTrav	DevNA	DevFail	Timeout
Mask	1	1	1	1	1	1	1	1	1
State	0	0	0	0	0	0	0	0	0

SUBSYSTEM STATUS (AS OF EOD SOL 54):

S/S	Status	Comments
C&N	Nominal	Y accel back to normal
MTM	Nominal	None
Thermal	Nominal	None
Power	Nominal	None
Telecom	Nominal	None

 4041 turn_by    (-4934,-3718) 418D: DIFF0 ART0 AX0 AY1 AZ1
 4041 turn_by    (-4934,-3718) 3F72: DIFF0 ART0 AX0 AY0 AZ2
 4041 turn_by    (-4934,-3718) 3C86: DIFF0 ART0 AX0 AY0 AZ1
 4041 turn_by    (-4934,-3718) 399B: RB0 DIFF1 ART0 AX0 AY0 AZ1
 4041 turn_by    (-4934,-3718) 36F7: LB0 RB0 DIFF1 ART2 AX0 AY0 AZ1
 4041 turn_by    (-4934,-3718) 33E0: LB0 RB0 DIFF2 ART2 AX0 AZ1
 4041 turn_by    (-4934,-3718) 3230: LB1 RB0 DIFF2 ART2 AX0 AZ1
 4047 deploy_apxs (    0,    0) 0000: LB1 RB0 DIFF2 ART2 AX0 AZ2
 4047 deploy_apxs (    0,    0) 0000: LB1 RB0 DIFF2 ART2 AX0 AZ2

DATA VOLUME SUMMARY (BY APID)

APID   #PKTS     #BYTES    #Mbits
----------------------------------
  4       30      8817     0.07054
  5      127      5145     0.04116
  6        7       420     0.00336
  7        8       332     0.00266
  8        0         0     0.00000
  9        0         0     0.00000
 10        0         0     0.00000
 12        0         0     0.00000
 23        0         0     0.00000
 24        0         0     0.00000
 25       54     94402     0.75522
 29        1       328     0.00262
----------------------------------
         227    109444     0.87555

*All data downlinked on this Sol INCLUDING retransmitted data.

NAVIGATION PERFORMANCE:

ACTIVITIES:

Retract the APXS and reposition the vehicle with rear vehicle facing Half Dome rock before placing the APXS on the rock.

• Vehicle initial position:
  • Rover thinks: (-4970, -3816, 88.5)
  • Driver thinks: (-4934, -3718, 93,2)

• Cmd #4033: Run APXS motor to 0; completed, no errors. End APXS position was -1.28degs, and max motor current was 115mA.
• Cmd #4041: Turn -40degs (left); incompleted, error 0xF01: Differential exceeded its navigation safety limit (16.48degs). Both left and right bogeys were also in extreme positions (left = 35.68degs and right = -22.16degs).
• Cmd #4047: APXS deploy to -1900cnts; incompleted, error 0xF01: Differential exceeded its navigation safety limit (same as above). Current APXS mechanism angle was -10.24degs.

  The APXS was retracted successfully after failing to place the APXS onto Halfdome rock yesterday. The turning-in-place command was failed due to the differential exceeded its navigation safety limit. The subsequent APXS deploy command was not carried out due to the same reason. Overall the X, Y and Z accels showed no anomalous readings today.

• The rover current position:
  • Rover thinks: (-4934, -3718, 70.6)
  • Driver thinks: (????)

  CONSTRAINTS:

• If the gyro is disable, odometry will be used to calculate the rover heading during turn-in-place. Consiquently, goto way point commands will not perform arch turns toward destination, however it will use turn-in-place to adjust its heading while driving toward waypoint destinations. Also, there will be no heading adjustment in the move commands.
• If risk level 2 is set, then the articulation hazard is disable (i.e. driving at your all risk!!!).
• Plan the Move command with distance 0.500m or less to avoid gyro drift.
• Do health check level 2 after every vehicle movement.
• Set Z accel to FORCED_BAD for all vehicle movements.
• Set Y accel to FORCED_BAD for short vehicle movements.
• Set Y accel to OK for RISK LEVEL = 2 vehicle movements.
• IF navigation sensor outside limit bit is set to ENABLE in HAZ_AVOIDANCE parameter (to avoid navigation command errored out because of Y accel exceeds navigation limit), the following considerations should be taken in to account:
  • Set command TIME OUT longer to allow the vehicle finishes up the command.
  • Check for clearance behind the vehicle at starting position, the vehicle might back up half of the vehicle length (300mm).

THERMAL PERFORMANCE:

Pending

TELECOM PERFORMANCE

Pending

MOBILITY PERFORMANCE:

Pending

POWER PERFORMANCE:

Pending

• None

TBD