diode.
Noise measurement shows 4 ppm noise. Timing of pulses and
bridge error signal are checked. Calibration conclusions are
made through comparison measurements with NIST traceable standards.
Deviations are small and refined through further measurement.
SIM Instrument
To date all SIM sub-assemblies have been thoroughly tested.
SIM has some hours of operating time on the SORCE IM. SIM
possesses a very clean vacuum environment. Initial FOV maps
came out reasonably well, but additional refinement is desired.
Prism transmission measurements have begun. SIM solar spectra
have been achieved and recorded. SIM solar simulator tests
have started, including the test of detectors and CCD with
~1 sun intensity and scattered light tests. Additional prism
transmission measurement tests are planned for the SIM ESR
(Electrical Substitution Radiometer). BG-20 filters will be
incorporated with a light source to give a secondary wavelength
standard. Vacuum testing in the Bemco tank will also be performed
on the SIM ESR at ambient and 10 C degrees.
SOLSTICE Instrument Status
SOLSTICE A integration, calibration and test are complete
with the exception of the SOLSTICE GCI Micro Electrical Interface
Testing. SOLSTICE B has now completed SURF (Synchrotron Ultraviolet
Radiation Facility) calibration. Still remaining are the Limited
Thermal-Vacuum Test, Final Preparation and Instrument Module
Installation. and SOLSTICE to GCI-Micro Electrical Interface
Testing also remains.
Both SOLSTICE A and B have completed Flight Instrument Assembly
and Alignment, LASP Optical Mechanical Functional Testing,
LASP Pre-Environmental Test Characterization, Final Assembly
and Environmental Test Preparation, Vibration Test and LASP
Post Vibration Test Verification. Some additional work is
required on the IM flight configuration. A quantitative assessment
of the detector head noise immunity and characterization of
noise on the high voltage monitor still remains. The SOLSTICE
B vacuum chamber and detector heater and optical cube also
need more testing
Orbital Spacecraft Bus Status
During the month of October, Orbital completed and successfully
tested the FPGA (Field Programmable Gate Array) redesigns
on the APE (Attitude Power Electronics) controller and micro
controller and delivered flight APE#2 to I&T (Integration
and Test). Preliminary cross-strapping and interface testing
is underway prior to APE#2 FPGA change and subsequent ATP
(Acceptance Test Procedures).
Orbital has received the Orb View-4 EDU's (Engineering Development
Units) and the reconfiguration of OV-4's APE is nearly complete.
This unit will be functionally identical to the SORCE ED.
The CEU EDU from OV-4 was used to debug vibe failure. The
battery integration has been completed, and safe to mate tests
have been successfully run.
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The
S/A (Solar Array) simulator installation is complete. Alenia,
supplier of the SORCE transceiver has reworked SN#1 and
performed the Delta-TVAC (Thermal Vacuum). The EMC (Electromagnetic
Compatibility) was completed on SN#2. Both units are in
final functional testing and Pre-Ship review is scheduled
through November 8 - 9, 2001. Orbital has received four
of the twelve SORCE solar panels. The remaining eight panels
are being readied for shipment.
Orbital supported the October 1, 2001 TIM (Technical Interchange
Meeting) with GSFC and LASP. A signed ECP (Engineering Change
Proposal) permitting SORCE "gyro less" flight
resulted from the meeting.
FSW (Flight Software) build 4.0 has been completed, and
its formal release will occur in early November 2001.
The 4th RWA (Reaction Wheel Assembly), RWE (Reaction Wheel
Electronics), 3rd MTB (Magnetic Torquer Bar), FSSE (Fine
Sun Sensor Electronics), FSS (Fine Sun Sensor) and trackers
have been integrated on the SORCE spacecraft bus. The thermal
subsystem integration is also complete.
The ACS (Attitude Control System) hardware subsystem testing
has begun, RWAs and TAMs (Three Axis Magnetometers) have
been tested, and the FSS and trackers are in the test process.
A new backplane for the CEU#1 has been built, due to a vibe
failure resulting from enlarged connector sockets. The backplane
passed 3-axis vibe, and is now in TVAC test.
The BPT (Bus Performance Test) procedure has been written
and practiced in dry run sessions. Redlines and modifications
have been done and the release of the BPT procedure is expected
by the middle of November 2001. Current schedules show the
completion of the final BPT prior to December 25, 2001.
But the BPT schedule is tight and success-oriented. Further
delays could impact bus availability, although bus delivery
still supports the SORCE instruments delivery date. The
SORCE transceiver delivery is later than anticipated due
to failures and rework at Alenia. Further delays could impact
the BPT scheduling.
APE cross-strapping test identified a blocking diode would
be needed to maintain high impedance of the unpowered APE.
Other interface issues resulting from test are still developing.
Upcoming
Meetings:
SORCE Scientists and Engineers plan to present
papers and attend the following meetings:
- AGU, San Francisco, CA December 2001
- MIWG, Boulder, CO Mid-January 2002
- SORCE Calibration Workshop Gaithersburg, MD January 2002
- NEWRAD at NIST, Gaithersburg, MD delayed to Spring 2002
To submit information please contact: Kathy.Lozier@lasp.colorado.edu |
