ISS MER Management’s Daily Notes Wednesday, June 20, 2001 (GMT 171) – 12:00 pm
The following notes highlight the ISS activities within the last 24 hours that were discussed during the morning NASA and Boeing management teleconferences, as well as the daily MER Management & Subsystem Tag-Up. These notes are not intended to provide the current configuration of the ISS systems, nor are they intended to capture all of the events that have occurred in the past 24-hour period or that are planned for the next 24-48-hour period. For a detailed overview of the last 24-hour period and upcoming ISS events, refer to the “0800 Report” and “Daily Report”, published by MOD on its Mission Control Center (MCC) website at http://mod.jsc.nasa.gov/mcc (select “Realtime Mission,” then “ISS Msgs”).
DDCU LA1B Bit Flip: As discussed in yesterday’s Daily Notes, a bit flip in Block 10 of the DDCU EEPROM was detected as part of the weekly BDTs performed to detect additional bit flips in ORUs that already have bit flips that haven’t yet been refreshed. Block 10 contains critical code for trip processing, hindsight buffer, and most importantly mode code and command processing. A subsequent BDT was completed yesterday afternoon and the Block 10 bit flip was not present, confirming that the bit flip is intermittent. Therefore, the MOD PHALCON and MER PHOENIX teams concurred that the DDCU should be commanded to operate in SRAM-mode. (When ORUs containing these EEPROMs are first powered up, their firmware is copied into SRAM, ensuring that a good copy of the firmware is available.) The switch to SRAM is planned for sometime this morning. Work continues toward developing the CCS patch that is required to enable refresh of the core Lab DDCUs to be performed. (This same patch will also enable DDCU LA2B, which also exhibited a bit flip yesterday, to be refreshed.)
DDCU P62B Refresh: The Flight Control Team discontinued this procedure when the validation dump of the patch (after it was uploaded and prior to the start of the actual refresh) did not match the expected value. Investigation determined that the expected value provided to the FCT was in error. This value will be certified and retransmitted to the FCT. Expect that refresh can be re-attempted tomorrow.
Node 1 RPCM N13B-A: PHALCON reported that they are unable to close RPC-1 in RPCM N1-3BA. The RPC powers the Emergency Egress Lighting Power Supply within the Node 1. Several close commands were sent. All commands were accepted but the RPC-1 switch status telemetry (based on RPC output voltage) never showed the RPC closed. However, BDTs show the discrete output status of the RPC as closed. In other words, internal telemetry shows the RPC is closed but external telemetry shows it is open. An ART has been formed to investigate.
CMG-1 Loss of Comm: CMG-1 again experienced a loss of comm; same signature that was seen on Saturday for CMG-1 and 4 times on CMG-2. The recovery procedure was used successfully to recover CMG-1. At present, all CMGs are in the control law and performance is nominal.
PCU Testing: PCU cold Start-up testing continues. Have completed tests at 6, 5, 3, 0, and –3 degrees C.
IFI Database: The MER’s In-Flight Anomaly Investigation (IFI) Database upgrade was completed yesterday afternoon. The new database can be accessed from the MER’s website at http:/mer.jsc.nasa.gov. Instructions for configuring a computer to access the new database are also available from the website. The old version of the database has been reconfigured to “read only” and will remain accessible for the remainder of the week to allow for any access problems to the new version by users to be resolved.
Spare SASA Decision – Option 2: Management chose option 2 – Do not make any hardware modifications, but change installation configuration so that one end of the Y-Jumper is not installed to the spare SASA, thus leaving it un-powered and thermally zero-fault tolerant. (The spare SASA and prime SASA have the same RT address and share the same data bus. If the spare SASA were to be powered up while the prime SASA is powered up, the resulting conflict would cause a loss of communications and potentially damage the bus.)
Event Code Clearance: The procedure defined in CHIT ISS0066 to clear event codes in the Primary Node 1 MDM. Commands from Scratch were built, tested, and delivered
MCOR: The MCOR heartbeat was lost for 16 minutes and then recovered. MCOR ART will investigate.
New IFIs Generated Within the Last 24-Hours
DDCU-LA2B Health Flag
PMA-2 Connector Panel MLI Loose
MCOR Loss of Heartbeat
Today’s Events (GMT 2001/171):
PCU Testing (continuing throughout the week)
Re-attempt to refresh DDCU-P62B
Switch DDCU LA1B to operate from SRAM (if approved)
Review of tomorrow’s SSRMS operations and DOUG testing plans
Upcoming Events for GMT 2001/172-173 (i.e., Thursday, Friday):
Thursday: Payload operations, SSRMS operations and DOUG test, ROBO conference
Friday: FD/Crew Tag-Up, CKB-2 Install; U.S. PAO Event; MAS Analysis T+2, Food Supply Inv.; ARIS ICE Ops; (IWIS / TVIS Test delayed tentatively delayed until next week)
Other Upcoming Events:
BP/ECG ART – Wednesday, June 20, 2001, 3pm, MER Conference Room
RPC/DDCU ART – Wednesday, June 20, 2001, 2pm, Location TBD
Smoke Detector ART – Thursday, June 21, 9am – MER Conference Room
