Section 9 Subsystem Status

1
Section 9 Subsystem Status
2
Attitude Control System
. . . Paul Sanneman ACS Lead
3
Changes Since S/C Thermal Vacuum

• ACS Components
• AST removed and X-rayed subsequent
  removal/replacement of EMI Filter with additional
  clearance between part and PWB (1/00)
• Debris found under EMI Filter and removed during
  repair
• AST removed and opened for addition of stiffener
  on the lid of Interpoint DC/DC converter (5/00)
  reintegrated in flight orientation (6/00)
• Removed IRU to prevent helium exposure during MAP
  testing (2/00) re-integrated with upgraded purge
  (5/00)
• ACE Software
• ACE RSN SW update to A/D conversion
  implementation (3/00?)
• ACE RSN SW update for IRAM2 checksum protection
  and removal of high rate event message (6/00)

4
Changes Since S/C Thermal Vacuum (continued)

• ACS Software
• Ephemeris epoch time changes from MET to UT to
  improve navigation propagation accuracy (M5 clock
  drift) (12/99)
• Modified Warm restart logic to ensure consistent
  recovery time (3/00)
• ACS table parameters updated via STOL procedures
  (5/00)
• Table 78 X-band Theta angle limit increase from
  60 to 65 deg
• Table 90 Disable autonomous re-entry into Delta-V
  mode
• Table 53 Increase pitch attitude FDC count from
  30 to 80 sec
• Table 87 Adjust solar array FDC limits to avoid
  trips during normal slew maneuver operations

5
ACS Summary

• Trending data to be collected using same
  procedure as T/V I
• ACS trends from T/V I available for reference
• IRU PDV has remained stable
• RWA runup/rundown in vacuum to be measured
• Open Problem Reports
• 468-20-4 IRU Parametric Drive Voltage
• Star Tracker temperature trends to be
  monitored/controlled closely with thermal
  engineering as in T/V I
• Thermal limits in database have been reviewed
• Special ACS steps during T/V II have been
  coordinated
• RWA Overspeed, AST TEC, ACE MTB Pwr Supply, GPS
  Ant feeds

6
IRU PDV Processed Trend
7
IRU PDV Data Trend
8
ACS

• Coarse Sun Sensors 1, 2 and 3 remain in
  non-flight configuration of the SAD test bracket
  until after T/V II test

Attitude Control Subsystem is ready for T/V II
test.
9
Attitude Control Determination Subsystem (ACDS)
. . . Philip Luers GSFC ACDS Lead
. . . Steve Schumacher Swales ACDS Lead
10
ACDS Readiness

• ACDS hardware is in Final Flight Configuration
• Hardware modification since last T/V test
• Stiffeners added to Interpoint power converters
  on ACE I/O and CDH LVPC boards
• Ceramic barrels on 1773 bulkhead connectors
  replaced with Phosphor-Bronze
• Powered vibration (workmanship) performed on 1
  axis
• Re-integration was nominal
• No Open Problem Reports

11
ACDS Plans

• Trending Plans (exactly like last T/V test)
• 4 voltages, 4 currents, 4 temperatures recorded
  every 5 minutes, graphed and analyzed for
  correlation with temperature
• Confirm oscillator drift measurements made during
  last T/V test
• Correlates spacecraft time adjustments with
  temperature
• No work required before pump down
• Critical limits in database confirmed
• Procedures have been reviewed

12
Power
. . . Allan Billings Power System Lead
13
Status of Flight Hardware/Software

• PSE in Final Configuration including Software
• Changes since Thermal Vacuum
• SOFTWARE The new PSE version ( "8.00" ) was
  loaded, with the 8 wait states modified A/D
  read routine. NO significant increases in the
  execution time of the control loop was
  observable, i.e, execution time 1.6 msec.
• SOFTWARE All PSE RSN Commands verified
• HARDWARE LVPC switched service 9 abandoned due
  to damage caused by short during last thermal
  vacuum test. Added new thermal wiring and
  rerouted.
• HARDWARE Fuse plugs added to all PSE LVPC
  outputs (non-essential services)

14
Status of Flight Hardware/Software

• Battery---In Storage, Ready for Flight
• Solar Array---After Integration of Solar Array to
  the Spacecraft, the Solar Array Will Be in Final
  Flight Configuration
• Changes since last thermal vacuum
• LAPSS Test performed on Array at Goddard at
  beginning of this year---Measured string current
  agreed with Tecstar values within 4. Open
  circuit voltage of strings agreed with Tecstar
  values within 100mV. All string V/I curves were
  smooth.

15
Open Problem Reports

• PR837-20-1 (RFA 33 4/12)
• Anomaly---
• PLVPCLDI2 telemetry went to FF (Maximum value)
  with no active spacecraft activity. PLVPCLDI2
  reports the total load current magnitude for the
  PSE LVPC. FF would correspond to 19.275A.
• This anomaly never occurred before and never
  happened again.
• The anomaly lasted only for one sample. If this
  was a valid out of tolerance current indication,
  the pulse width lasted less than 533uS since the
  anomaly did not trip the LVPC over current
  protection circuit.
• The spacecraft configuration was set to load the
  software into the housekeeping RSN. It is
  possible that something in this configuration
  contributed to this anomaly (unknown at this
  time). This configuration is a ground
  configuration and will not be used in flight.

16
Open Problem Reports

• Investigations
• Analyzed PSE LVPC timing as a possible source of
  the Anomaly. If one assumes worst case timing for
  all the individual ICs we still have positive
  margin from the time the LVPC places data on the
  bus until the RSN reads the data. However the
  margin appeared to be less than adequate and the
  MAP ETU PSE LVPC was tested to measure actual
  (not theoretical) timing margin. The margin
  measured on MAP was adequate.
• The spacecraft harness was examined by quality
  control (EO1-WOA-963) and found to pass visual
  inspection.
• The FEDS data system was analyzed to determine if
  it was the source of the anomaly. The conclusion
  was that the telemetry (PLVPCLDI2)reported down
  from the spacecraft had FF. This was not a FEDS
  problem.

17
Open Problem Reports

• Disposition
• A fault tree analysis was performed as a result
  of RFA 4/12 and no credible source of the failure
  other than the spacecraft configuration was
  found. It is speculated that the spacecraft
  configuration may have been responsible and this
  configuration will not be used in flight.
• If a similar (benign) anomaly is generated on
  orbit (PLVPCLDI2FF for one sample) a red limit
  violation would occur and this would be observed
  in ground data. No other spacecraft consequences
  would accrue.
• We will continue to monitor for this anomaly
  throughout all spacecraft testing.

18
Trending Plans/Critical Limits/Additional Work
before Pump down

• Trending Plans
• Trending requirements passed on to MOC
• MOC is utilizing a heritage data collection and
  trending system from TRACE (DTAS)
• Trending procedures are currently being
  implemented. Completion expected soon after
  Thermal Vacuum Test.
• Critical Limits
• Critical Limits have been placed in ASIST work
  stations. All other limits undergoing thorough
  review.
• Additional Work Before Thermal Vacuum
• The test battery will be reconditioned before
  Thermal Vacuum

19
RF Communications
. . . Bill Jupin / Pete Young / Ken Perko EO-1 RF
Comm Team
20
RF Communications

• Entire Subsystem in Final Flight Configuration
• X-Band Hat Coupler repaired
• No Open Problem Reports
• Automatic Trending Script has been updated
• No further work required before Pump Down
• Helping with GPS GSE Configuration and Setup
• Critical limits in the ASIST Database are being
  reviewed
• Procedures almost identical to TVAC 1
• Only remaining item to verify during TVAC 2
• Must see X-Band Antenna Track and Dump Data to
  Various Ground Stations During Orbits. Want to
  Witness Entire Process During TVAC (ACS
  commanding, Phase Shifters Changing State in
  Antenna, RF Activation, etc).

21
Wideband Advanced Recorder Processor (WARP)
. . . Terry Smith WARP Lead Engineer
22
Status

• Hardware is in its final flight configuration
• Software is in its final flight configuration
• There are no open problem reports
• No work is required before pump down

23
Changes Since Last Thermal Vacuum Test

• A voltage reference part failed (open) on the
  WARP LVPC on 1/4/00
• The failure produced a high voltage within the
  LVPC
• Numerous parts were over-stressed
• The entire LVPC piggyback card was replaced
• The WARP successfully completed an extensive
  re-qualification program
• The WARP was operated over 400 hours prior to
  re-integration on the S/C

24
Trending Plans

• The following parameters will be monitored each
  day
• Mode of operation
• Primary input power voltage
• All secondary voltages
• The temperature of the front and back of every
  card
• RF Exciter Power Output

25
Critical Limits Procedures

• The Processor Card Mongoose V Temperature
  sometimes reaches the yellow limit during the hot
  plateau
• The heater mode procedure must be run prior to a
  memory card cold start. If the WARP fails to
  power up the memory cards, no harm is done.

26
Flight Software
. . . Ray Whitley EO-1 Flight Software Systems
Manager
27
Flight Software Readiness

• No T/V II Concerns/Liens
• There are no know leans against or issues with
  the flight software at this time. (What a
  difference 7 months makes!)
• Code Walk-throughs have been conducted for the
  HSK and X-Band RSNs since TV-I
• Code 300 ran code analyzer s/w against most of
  EO-1s FSW with very positive results
• FSW testbed has been re-located to GSFC from
  Swales an ACE ETU fabrication is in progress
• Thanks to Tom Feild Emory Stagmer, all TSMs
  RTSs are incorporated and tested at the
  spacecraft
• ESN A/D converter wait state timing issues
  understood resolved (compliments of MAP h/w and
  s/w engineers). EO-1 fix installed and tested
• 1773 Bus Controller s/w hardened against possible
  failure mode

28
Flight Software Readiness

• No T/V II Concerns/Liens
• There are no open software PTRs that require
  software change in any of the flight processors.
  EO-1 PTRs generated over the last year have been
  analyzed for severity, and the results indicate a
  very positive trend toward zero(0) make-play
  changes.
• PTRs have been cross-checked against the MAP
  problem database
• There are no open PARs/PRs in the S/C IT
  database that require software change in any of
  the flight processors

29
Flight Software Readiness

• Have Been Ready To Go for Several Months

30
Reaction Control System
. . . Mike McCullough RCS Lead Engineer
31
Reaction Control System

• Configuration for Test
• Pressurized to 40 PSIG w/ GN2 (Long Term Leak
  Check)
• Enable Plug Test Set (EPTS) Installed
• Thrusters Valves Will Not Be Actuated
• Components Functions to be Tested
• Thruster Drive Voltage Recorded on Strip Chard
  via EPTS
• Catalyst Bed Heaters Enabled via EPTS
• Thermal Control Heaters (Primary Redundant)
• Pressure Transducer Temperature Telemetry
• Latch Valve Function (Part of CPT5)

32
Reaction Control System

• Additional Testing for T/V II
• RCS Secondary Heaters Will Be Exercised
• Primary Heaters Function Sizing Verified During
  T/V I
• Secondary Heaters Will Control System 12-18C
• No Open Problem Records
• RCS is ready for Thermal Vacuum testing

33
Mechanical
. . . Pete Alea Mechanical Systems Engineer
34
Satellite Support Stand
35
EO-1 Satellite Test Configuration
Chamber 225
36
Chamber Configuration
Chamber 225
Satellite Test Stand
37
Test Readiness

• Two open problem records - WOA 1028, Event 50
  80
• Insufficient gas flow rate from purge cart to
  support both IRU and SI
• Purge cart modifications in progress to replace
  regulator and flow meter to provide increase flow
  rate. MIT/LL has approved required changes
• Test fixture and support hardware has been
  completed and is ready to support T/V test
• Satellite handling procedures ready and WOA is in
  place
• There are no outstanding mechanical PRs or liens
  against the S/C which may delay testing

38
Global Positioning System
. . . David Quinn GPS Lead
39
Global Positioning System

• Entire Subsystem in Final Flight Configuration
• Stiffener hat added to PCU Interpoint DC/DC
  Converter
• 1-axis Vibration
• Successfully Reintegrated into S/C
• Ground System Command Interfaces Online
• RF GSE Upgraded from TVAC-1
• Hat Coupler Gaps Reduced
• Noisy RG-142 RF Cables Removed
• Rooftop Antenna Relocated
• Low Noise Belden 9913 Cable Runs - Reduced in
  Length Over TVAC-1
• No Open Problem Reports
• Temperature Trends to be Monitored as Part of
  TVAC-2
• RF GSE Testing Required Before Pump Down
• Limits Reviewed Prior to TVAC-1 - Valid and
  Unchanged.
• Procedures Almost Identical to TVAC-1
• More Attention Given to Signal Levels From All
  Four Antennas

40
TVAC II Setup