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Table 7-1. Ranger 6 Configuration of TV-OSE Umbilical Wiring
From (RCA Designation)
Table 7-2. Present Configuration of TV-OSE Umbilical Wiring
* Umbilical Designation
**Figure 7-1 RCA System-JPL System Interface Designation
Change scale factor of the "F" and "P"' HCR outputs to increase sensitivity.
The 15 point telemetry changes are as follows:
Increase sensitivity on "F" and "P" battery terminal voltage to cover from 26 to 36 volts.
Measure 8 hour increments and indicate the starting of the clock.
Increase sensitivity in LCR output measurement.
Additional preventive measures are being taken in the areas of thermal control, packaging, parts usage, quality assurance, and testing. Because the exact cause of failure
in RA-6 is undetermined, all practical steps are being taken to eliminate other less likely but possible failure causes.
1. Thermal Control
As indicated in Appendix J, the temperature at which the TV tower stabilized was 25 to 40°F higher than expected. Based upon the analysis of this difference, it was concluded that the paint emissivity/absorbtivity characteristic should be modified such that the stabilization temperature would be lowered 20°F.
Increasing the gauge of the DCU mounting base from 0.040 to 0.062 inches.
3) Securing relays, cabling, and other heavy parts with additional spot
Improving cable tie-down by changing Ty wraps to clamps or improved Ty wraps.
Adding a backup locking device (lockwire or stycast) to the bulkhead
Adding potting to the backside of connectors to improve the insulation over
Further insulation of conductors and components.
No additional venting appears to be necessary.
3. Parts Usage
Additional design reviews have been conducted both by RCA and JPL in the area of parts reliability. In some instances, these reviews have resulted in part changes in order to improve the derating factors.
To increase reliability to the fullest extent, the quality assurance efforts have been expanded in both the areas of fabrication and testing. In addition to the RCA inspection
there will be 100 percent JPL inspection. Detailed inspection criteria have been generated wherever necessary. Monitoring of all testing is being accomplished. Additional support for the review of failure reports by both RCA and JPL has also been implemented.
A review of the test program resulted in modest changes to the TV Subsystem and spacecraft testing. These changes are aimed primarily at improving the simulation of flight conditions.
Retesting will be accomplished for those units that contain voltages during the boost phase.
The 'no cables" testing of the entire spacecraft will be extended to include not only the launch and midcourse phases but also the terminal phase.
REDUCTION OF CHANNEL 8 TELEMETRY DATA
A. EQUIPMENT AND MAGNETIC TAPES USED
Obtaining the data used in the analysis of Section V involved the following operations:
Records taken from flight tapes were played back on one tape reproducer
All data were taken from magnetic tape recording Track No. 6. These were
3) The calibrations and adjustments were not changed after the initial settings were established.
From these recordings the telemetry data were extracted and tabulated in Tables A-1 through A-5. The calibration charts in Figures A-1 through A-8 were used to obtain the actual voltages and temperatures given in Section V. In these reductions no extra effort was applied to correct for insignificant errors in interpolation or parallax.
A second method of extracting the information from the magnetic tapes was also utilized. This method involved the use of a digital decommutator to eliminate baseline drift and correct for calibration shifts. A computer was also used to convert the octal readout of the decommutator to engineering units.
The data reduced by digital techniques were used to verify the readings made from the analog records. Although the absolute values of the digitized data did not agree precisely with the analog readings, there was sufficient correlation between readings.
A Gerber variable scale rule was used to read the analog telemetry data. For each frame of data the scale was set to read 4. 65 on the Channel 8 reference point number 12. The scaling was checked by reading the amplitude of the zero reference pulse (point 13), which should read 1. 15 units. These two values represented the full scale and pedestal voltages as measured on flight III-1 before launch. Independent readings were taken by different operators to ensure agreement and accuracy of the readings. It is felt that the Gerber can be read reliably to an accuracy of 1/2 a division, which is 50 mv on the telemetry readings.