Sequence 57710D:

• Received telemetry for commands 27052 through 27134, when sequence was aborted as planned by sequence 57810A.
• ALL APXS spectra (of air) were received ... again ... hooray!
• Overall rover health is excellent.

Sequence 57810A:

• Sequence was once again queued late by about 15 minutes.
• Everything was fine up to the Position APXS command. From the telemetry and the EOD image it appears that the command turn of approximately 40 degrees was perhaps overkill. On its way backwards towards Chimp the left side of the vehicle was lined up perfectly to drive over the (2) softball size rocks in front of Chimp. When the LMW got up on top of the second rock (the larger of the two), the LFW was down between the two rocks and the LRW was down on the back side of the second rock thereby putting the left side rocker and bogie into an extreme configuration with the bogie essentially at its mechanical stop. This configuration exceeded a Level 1 articulation hazard (the level at which we were driving at) and caused the vehicle to prematurely stop.

  Ah! I guess those downlink guys were right after all ... we should have turned by about 10-15 degrees

• The right side wheels are basically on level terrain.
• Vehicle slightly pitched forward and slightly rolled to the right.
• All (3) accels appear to be working fine (i.e., no anomalous readings)
• Received all rover data up to time when LMRE was turned off.
• Rover movie only contained 3 images all of which were the same (i.e., the timing appears to have been off.
• Rover's overall health remains excellent.

• 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

Operational Constraints (for Sol 77 Sequence):

1. New or changed recommendations:
   
   • The downlink team feels that we need to take a more perpendicular approach to the face of Chimp to insure that we don't drive up it with the RRW which has the additional problem of tilting us away from the afternoon Sun. This can be accomplished by one of the following two approaches:

     1) Disable the differential. Turn counterclockwise by 20 degrees. Position APXS (~0.3 meters)

     2) Retract APXS. Disable the differential. Drive forward 0.8 meters. Turn counterclockwise by 20 degrees. Enable the differential. Set Risk level to 2. Partially deploy APXS. Position APXS (~1.0 meters).

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 (EOD Sol 78):

Execution:	Off-Nominal (Art Hazard)
State:	Running
Wakeup:	? MLST
Crit Errors:	Articulation Hazard (Lvl 1)
Executing sequence 57810A

VEHICLE STATE: (AS OF COMMAND: 28060, Clear Errors
SCET: 9/22/97 04:??, MLST: Sol 78 11:?? )

Mission Phase:	Primary
Mode:	Nominal
Config:	APXS partially deployed
	LMW way up, Risk Lvl 1 hazard
	Left Bogie at Mechanical Stop
Device Status:	Gyro forced okay, Never Power
	Y accel force failed
	Z accel force failed
	RFW temp. force failed
	Batteries Force Failed
Temp (Internal):	Nominal
Temp (External):	Nominal
Temp:(Modem):	Nominal

   Parameter     Initial      Final    IMP EOD    Parameter    Initial     Final
---------------------------------------------------------------------------------
X Position (m)      ?       -8.865      ?      LBogie (deg)       ?      +32.88
Y Position (m)      ?       -2.425      ?      Rbogie (deg)       ?      +12.24
Heading   (deg)     ?      +65.1        ?      Diff   (deg)       ?      + 6.00

Pitch    (deg)      ?       +8.3     (+ Pitch -> Front down)
Roll     (deg)      ?       -5.9     (+ Roll  -> Roll to Starboard)

ADM Pos  (deg)      ?      -66.56    (Partially Deployed)

LFS      (deg)      ?       +0.6           RFS    (deg)       ?    -2.6
LRS      (deg)      ?       -1.3           RRS    (deg)       ?    -1.3
--------------------------------------------------------------------------------

BATTERY STATE/USAGE(AS OF EOD SOL 78)

BATTERIES DEPLETED