First light tests for SIM have been conducted. Spectrum was measured
through all focal plane diodes. Further study is ongoing concerning
the focal properties of the spectrometer. Wavelength calibration
performed well in the prism and diodes and a mercury spectrum
was obtained. Scans on the mercury spectrum will be repeated to
check for stray light and compared to SOLSTICE mercury scans,
for accuracy. The CCD failure has been resolved by Goddard Space
Flight Center. GSFC could not duplicate the failure, and a malfunctioning
resistor may have been the initial cause failure. The suspect
CCD has been demoted to a flight backup because of excessive handling.
CCD boards are at an outside vendor for fabrication. ESR (electrical
substitution radiometer) characterization is a bit behind schedule.
The SIM ESR code needs test, the calibrator system is ready for
assembly, the sunshade is at NCAR for fabrication. Internal harnessing
is underway, and work is ongoing for the vacuum feedthroughs,
internal bus board, and mechanism flight wiring. The vacuum door
is ready for assembly. Final work on the kinematic mounts is underway,
and housekeeping thermistors need to be added to the case.
SOLSTICE is well into testing. Flight instrument assembly and
alignment are complete. LASP optical mechanical functional testing,
LASP pre-environmental test calibration, and SURF Calibration
#1 "A"is finished. Instrument (mechanical, optical,
grating drive and detector assemblies) end-to-end testing is complete
and the instrument performance meets or exceeds requirements on
the bench. Thermal/vacuum test to test alignment stability is
complete. Characterization, loose ends resolution, and adjustments
Last month XPS was essentially built, except for testing. Environmental
test and FOV (field of view), tests are now done. XPS/MU interface
testing is underway. It seems that some investigative work is
needed on the FPGA (flight programmable gate array) due to a nonperforming
component. A JPL tiger team has been assembled to evaluate the
part, and recommend resolution.
A MIWG (Mission
Integration Working Group) was held April 4-5, 2001 at the Pegasus
Rocket facility in Chandler, Arizona. It was determined that a
Stage 3 camera is too expensive to implement on SORCE. The SORCE
fairing and avionics deck are in house at the Chandler Rocket
module harness is 90% routed and the instrument module MGSE (mechanical
ground support equipment) cradle is being fabricated at NCAR (National
Center for Atmospheric Research) and Zimmerman, an outside vendor,
and the EGSE (electrical ground support equipment) rack is in
use. The thermal XPS status analysis is complete pending internal
review, and the TIM analysis is in process. The SORCE FMEA (failure
mode and effects analysis), FTA (fault tree analysis) and PRA,
(probability risk assessment) have been delivered to the Aerospace
Corporation for review. The Aerospace Corporation is the parent
body of the SORCE Red Team. OASIS-CC development end-to-end testing
has resulted in the complete verification of command and telemetry
functionality. XPS testing is complete on the flight instrument,
TIM testing is in progress, SIM, SOLSTICE, and MU CSTOL scripts
and procedures are 80% complete. Functional testing will follow
after end-to end testing is complete. Module testing will follow
functional testing. Additional requirements may become evident
after the instrument functionals are complete. Power, mass and
memory budgets are adequate, but instrument mass margin has been
consumed. Measured values of power should be obtained in the near
future, as well as mass measured values.
Recent accomplishments include the fabrication of a new bench
(due to damaged laminate) and bearing cups (due to a tolerancing
error) and the successful completion of the primary structure.
The APE EDU (attitude power electronics engineering development
unit) was tested with the box EGSE (electrical ground support
equipment) and the unit was delivered to Flat Sat (test flat satellite).
Twenty-five of thirty-two flight cards are complete. A successful
Solar Array CDR was held and solar array substrates have been
sent to SpectroLab for cell population. Shock test of the EDU
fine sun sensor was successful following rework for prior test
failure. RWE (reaction wheel electronics) vibration failure has
been resolved and corrective action is underway. Orbital hosted
a TIM (technical interface meeting) with LASP to review the SORCE
bus integration and test schedule in light of structure delays.
Orbital has reduced their thermal vacuum test schedule from 18
½ cycles to 8 cycles to accommodate the late delivery of
spacecraft components, and to meet I&T schedules. Flat Sat
SDVF (software development and verification facility) is underway.
Work has begun on the ECP (engineering change proposal) for spacecraft
gyroless mode implementation.