APOLLO 13 REVIEW BOARD RECOMMENDATION 3a THE WARNING SYSTEMS ON BOARD THE APOLLO SPACECRAFT AND IN THE MISSION CONTROL CENTER SHOULD BE CAREFULLY REVIEWED AND MODIFIED WHERE APPROPRIATE, WITH SPECIFIC ATTENTION TO THE FOLLOWING: INCREASING THE DIFFERENTIAL BETWEEN MASTER ALARM TRIP LEVELS RESPONSE REVIEW INDICATES THAT THE HYDROGEN TANK PRESSURE WARNING LIMIT APPROVED MODIFICATION KIT WILL BE INSTALLED WHERE APPROPRIATE CHART #5 Chart 5 (fig. 25), please. Here we come to a recommendation of the Review Board that has four sections to it. I will have a chart for each section. It basically addressed itself to the warming systems on board the Apollo spacecraft and in the Mission Control Center. It said these systems should be carefully reviewed and modified where appropriate. The first one addressed itself to looking at the differential that existed between master alarm trip levels and expected normal operating ranges. We have done that. Our review indicates that the hydrogen tank pressure warning limit is the only one of concern. There we have an approved modification kit to be installed in spacecraft where appropriate, to give us this wider range. APOLLO 13 REVIEW BOARD THE WARNING SYSTEMS ON BOARD THE APOLLO SPACECRAFT AND IN THE MISSION CHANGING THE CAUTION AND WARNING SYSTEM LOGIC TO PREVENT RESPONSE BLOCKING OF CRITICAL SYSTEM PARAMETERS MINIMIZED BY PROVIDING CHART #6 FIGURE 26 Chart 6 (fig. 26), please. Recommendation 3-B, here, referred to changing the caution and warning system logic to prevent an out-oflimits alarm from blocking another alarm when a second quantity in the same subsystem goes out of limits. Here we have had to resort to providing the second-level sensing on the ground in the Mission Control Center at Houston to minimize the effect of blocking of the critical system parameters. APOLLO 13 REVIEW BOARD THE WARNING SYSTEMS ON BOARD THE APOLLO SPACECRAFT AND IN THE MISSION ESTABLISHING A SECOND LEVEL OF LIMIT SENSING IN MISSION CONTROL RESPONSE THE CAPABILITY FOR SECOND LEVEL SENSING IS BEING IMPLEMENTED A MASTER ALARM LIGHT IN ADDITION TO THE PRESENT INDIVIDUAL WARNING LIGHTS IS BEING ADDED CHART #7 FIGURE 27 Chart 7 (fig. 27), please. Recommendation 3-C. This specifically talked of establishing a second-level sensing on the ground on critical quantities with a visual or audible alarm which could not be easily overlooked. That capability for second-level sensing is being implemented and we will have a master alarm light in addition to the present individual warning lights. APOLLO 13 REVIEW BOARD RECOMMENDATION 3d THE WARNING SYSTEMS ON BOARD THE APOLLO SPACECRAFT AND IN THE MISSION CONTROL CENTER SHOULD BE CAREFULLY REVIEWED AND MODIFIED WHERE APPROPRIATE, WITH SPECIFIC ATTENTION TO THE FOLLOWING: •PROVIDING INDEPENDENT TALKBACK INDICATORS FOR EACH OF THE SIX FUEL CELL REACTANT VALVES PLUS A MASTER ALARM WHEN ANY VALVE CLOSES RESPONSE MODIFICATION WILL PROVIDE A WARNING IN THE COMMAND MODULE WHEN ANY ONE OF THE SIX FUEL CELL REACTANT VALVES CLOSES CHART #8 Chart 8 (fig. 28). Recommendation 3-D. This addressed itself to providing independent talkback indicators for each of the six fuel cell reactant valves plus a master alarm when any valve closes. We will make a modification and provide a warning in the command module when any one of the six fuel cell reactant valves closes. APOLLO 13 REVIEW BOARD RECOMMENDATION 4 CONSUMABLES AND EMERGENCY EQUIPMENT IN THE LM AND THE CM SHOULD BE REVIEWED TO DETERMINE WHETHER STEPS SHOULD BE TAKEN TO ENHANCE THEIR POTENTIAL FOR USE IN A "LIFEBOAT" MODE RESPONSE MANNED SPACECRAFT CENTER CONDUCTING EXTENSIVE REVIEW OF LIFEBOAT CAPABILITIES CHART #9 FIGURE 29 Chart 9 (fig. 29). Recommendation 4. This addressed itself to reviewing the consummables and emergency equipment in the lunar module and command module to enhance their potential for use in a "lifeboat" mode. This review is underway. We have a very extensive review going on and we will be getting reports within the coming weeks on what we can do in addition to what we were able to do on Apollo 13. APOLLO 13 REVIEW BOARD RECOMMENDATION 5 THE MANNED SPACECRAFT CENTER SHOULD COMPLETE THE SPECIAL TESTS AND RESPONSE SPECIAL TESTS AND ANALYSES INITIATED BY INVESTIGATION WILL BE COMPLETED • LUNAR MODULE POWER SYSTEM ANOMALY MOST PROBABLE CAUSE LEAKING ELECTROLYTE RESULTED IN SHORT SEALING MODIFICATION WILL PRECLUDE FREE ELECTROLYTE FORMING OTHER NASA CENTERS ARE CONTINUING SUPPORT CHART #10 FIGURE 30 Chart 10 (fig. 30) recommendation 5. This addressed itself to completing the special tests and the analyses now underway. Our response there is those special tests and analyses initiated by the investigation will be completed. The second part of the recommendation addressed itself to the lunar module power system anomaly, saying that it should receive careful attention. The lunar module batteries which were powering Apollo 13 on the way home, did indicate a short circuit at approximately 97 hours into the mission, for a very short period of time 1 to 2 seconds. We have done a detailed analysis of the telemetry data that we had for that period of time and we have identified the most probable cause being leaking electrolyte which resulted in a short circuit. We plan to fix this by a sealing modification which will preclude free electrolyte from forming short circuits. The last part of that recommendation addressed itself to the other NASA centers which have given a very high level of support to the Manned Spacecraft Center in this area, to continue this support. Those centers will continue their support. Mr. GEHRIG. Dr. Petrone, the fix on the lunar module anomaly which is reported in the Board's finding No. 47, this will not have any significant cost or schedule impact on the program, then? Dr. PETRONE. We do not see this as a large fix. It is a matter of adding potting compound to areas that were exposed to possible electrolyte shorts and thereby sealing it. That would not be a high cost fix. APOLLO 13 REVIEW BOARD WHENEVER SIGNIFICANT ANOMALIES OCCUR IN CRITICAL SUBSYSTEMS DURING RESPONSE PRESENT PROCEDURE IN RESOLVING ANY ANOMALY RELIABILITY AND QUALITY ASSURANCE AUGMENTATION OF PRESENT PROCEDURES HARDWARE HISTORIES WILL ALSO BE REVIEWED BY TEST ENGINEERS FINDINGS WILL BE PRESENTED TO PROJECT ENGINEER •START PRESENT SYSTEM FOR RESOLVING IN-FLIGHT PROBLEMS EARLIER •EXPERTS RELOCATED AS REQUIRED CHART #11 FIGURE 31 |