are under development to plan for any conse-quences that could
develop from the potential launch overlap.
9. A problem was discovered in the Interpoint 5V flight power
converters. The converters deliver a 10V transient power spike
at instrument turn on. This power spike may harm sensi-tive
instrument electronic components. The faulty flight power converters
seem to originate in a single manufacturer's lot. Flight power
converters are long lead items to purchase and replacement could
impact all instrument build schedules. GSFC is helping to evaluate
the faulty parts, and the quoting and purchase of replacement
parts is underway. The converter problem must be fully defined,
affected parts must be identi-fied, damaged and new parts must
be tested, and, if necessary, replacement parts must be installed.
This could prove to be a lengthy process. The faulty parts may
have damaged SOL-STICE A and B, and the XPS instrument electronics.
XPS is totally assembled and awaiting the outcome of the FPGA
analysis. Faulty Interpoint 5V fight power converters may have
affected XPS electronics. The instrument will un-dergo evaluation
to determine the impact of the Interpoint 5v flight power converter
to its functioning.
The TIM instrument parts are 99% complete and all tests ex-cept
environmental test have been completed. The faulty flight power
converters did not affect TIM, because they had not yet been
placed in TIM equipment. Further TIM testing may be delayed
until different flight converters can be pur-chased, or a decision
is made regarding the use of Interpoint 5v flight converters
from a different lot. New TIM door mo-tors are arriving from
Ball Aerospace. In addition, TIM vac-uum door seals must be
perfected. New lubricants are being tested for superior sealing
abilities, and a new and heavier door may be designed to replace
the current TIM door, which bends under the pressure necessary
to completely vacuum seal the door.
parts are 98% fabricated. SIM electrical parts are 66% complete.
The assembly of SIM is well under-way, and additional shifts
may be added to meet assembly
ESR Elictrical Substitution Radiometer
A and B electrical parts are 96% complete and electrical parts
are 90% complete. The SOLSTICE instrument is basically complete
except for the Interpoint 5V flight con-verter
Additional research on the functionality of the SOLSTICE g-tube
has been completed.
Microprocessor Unit (MU) progress has been good. 75% of the mechanical
parts are complete, and 55% of the electrical parts are complete.
MU Software Coding is well underway. The SIM task is 50% complete
and little work remains on the SOLSTICE, TIM and XPS. An estimated
44 days of work remains for the completion of all coding processes.
The MU to the GCI (Generic Channel Interface) harness in-stallation
is complete. Final bonding should take place the week of June
26, 2001 and the integration with the EMU (En-gineering Microprocessor
Unit) as well. LPT's (Limited Per-formance Testing) with TIM,
SOLSTICE and XPS should fol-low.
Aerospace Corporation delivered the SORCE FMEA/FTA/PRA (Failure
Modes and Effects Analysis, Fault Tree Analysis, and Probabilistic
Risk Assessment) final re-sults. SORCE residual risks are acceptable.
The minimum success probability is 93.2% at 1.5 years, and full
mission suc-cess probability is 72.8% at 5 years. The most significant
risk to the SORCE mission is the single string RAD 6000. The PRE
(Power Regulator Electronics) shunt card is the most sig-nificant
contributor of residual risk for the spacecraft bus.
and MUFSW Status
Overall progress has been good. The EMU has been fully in-tegrated
and is in software testing. Simulations are in process to identify
bugs and eliminate them. Most flight instrument boards are complete
or nearly complete. Instrument interface testing will resume when
the Interpoint 5V power converter problem has been resolved.
The GCI (Generic Channel Interface) command telemetry ac-cepts
command and produces instrument and software status telemetry.
The initial DSP loading is complete, but command and telemetry
needs to be integrated. The MU analog/digital converter integration
is complete and all PCIIO functionality is complete. RAD6000 exceptions
and data can be trapped and recorded. Five days of PCIIO stress
testing revealed bugs, PCIIO EEPROM read errors, and PCIIO command
buffer bit flips. These problems were identified and isolated.
A single hardware issue may be causing these glitches and the
search for a common solution is underway. New CTSIM (Com-mand
and Telemetry Simulators) hardware are experiencing functional
difficulties. Ongoing work with the CTSIM vendor should bring
the units to operational status soon enabling fur-ther test.
Despite tribulations, SORCE progress has advanced and we remain
on schedule, and ready to circumvent setbacks with ef-fort and
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