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ZL2VAL > ROVERS 21.05.04 13:27l 76 Lines 3245 Bytes #999 (0) @ WW
BID : 800895ZL2VAL
Read: GUEST
Subj: Status, 18th & 20th May
Path: DB0FHN<DB0FOR<DB0SIF<DB0EA<DB0ACC<DB0GOS<ON0AR<ON0AR<7M3TJZ<IK1ZNW<
ZL2TZE<ZL2AB
Sent: 040521/1116Z @:ZL2AB.#46.NZL.OC #:40751 [New Plymouth] FBB7.00g
From: ZL2VAL@ZL2AB.#46.NZL.OC
To : ROVERS@WW
Update: Spirit and Opportunity
SPIRIT UPDATE: Spirit Gets an Unexpected Break. - sol 131-133, May 20, 2004
Spirit continued its trek to the "Columbia Hills" over the past four
sols, but took an unplanned break on Sols 131 and 132 due to a software
fault on sol 131. That fault left rover planners with some uncertainty
about Spirit's final position and attitude, so Sol 132 was spent
re-establishing that knowledge with panoramic, navigation and hazard
avoidance camera imaging of the rover's surroundings. The unplanned
break did have a silver lining though; it resulted in fully charged
batteries, paving the way for a long drive on Sol 133. Spirit roved 113
meters (370.7 feet) on Sol 133, with a record 78-meter (256 feet)
autonomous navigation segment. The previous record for an autonomous
navigation drive was 62 meters (203.4 feet) on sol 125. Spirit's
odometer now reads 2473 meters (1.53 miles) and it is roughly 780 meters
(.5 miles) from the Columbia Hills and in excellent health.
So what went wrong on sol 131? The flight software team is uncovering
the details, but it appears that the error occurred within a
3-microsecond window of vulnerability when a "write" command was
attempted to a "write-protected" area of RAM. The flight software team
believes this is an extremely low probability event, and has not
adjusted the planning process to avoid the miniscule period of
vulnerability. Opportunity has the same vulnerability to the fault.
------------------------------------------------------------------------
OPPORTUNITY UPDATE: A Sol for Rest and Recharging. - sol 112, May 18, 2004
Opportunity is healthy, but feeling a bit sluggish today. The rover's
40-meter (131 feet) traverse along the southern edge of "Endurance
Crater" on sol 111, and a sol 112 error with a Deep Space Network
command transmission have resulted in a low battery state of charge.
The sol 111 drive put Opportunity on an 8-degree slope that tilted the
rover away from the Sun and limited the amount of direct sunlight that
could reach the solar panels.
To help the battery recover to its normal state of charge, rover
planners had built a sol 112 plan that deleted two of the three UHF
windows. Unfortunately, a Deep Space Network configuration error
prevented the command load from reaching Opportunity on sol 112 and, as
expected in such cases, the rover executed the onboard run-out sequence,
which included an hour of remote sensing and the three on-board UHF
communication windows.
Sol 113 will be a sol for sleep and recharging for Opportunity. On sol
114, the rover will do some limited remote sensing in the morning, but
will generally take it easy over the next few sols in order to fully
charge the batteries. The limited activity over the next few sols will
focus on moving towards the Endurance Crater rim and a new position for
panoramic camera imaging.
=========================
73 de Alan, (Sysop ZL2AB).
AX25:ZL2VAL@ZL2AB.#46.NZL.OC
IP :zl2val@qsl.net
APRS:!3903.34S/17406.45E]
Message timed: 22:52 on 2004-May-21 (NZT)
Message sent using WinPack-AGW V6.80
Points to ponder
~~~~~~~~~~~~~~~~
Rural wisdom
------------
Don't corner something meaner than you.
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