The Apollo Spacecraft - A Chronology.|
Part 3 (A)
Man Circles the Moon, the Eagle Lands, and Manned Lunar Exploration
October 23, 1968 through November 1968
October 23LeRoy E. Day, Apollo Test Director, NASA Hq., informed Apollo Program Director Samuel C. Phillips of two failures of LM propellant tanks during testing, a problem that might have significant program impact on LMs 6 and 7 and subsequent vehicles. The particular tanks in question were those manufactured by Allison Division of General Motors but reworked under separate contract by Airite Division of Sargent Industries. The two tanks, lightweight SWIP II models slated for LM-6 and subsequent vehicles, had suffered small cracks in the welds. So far, said Day, the weld process used in manufacture of the tanks was "highly suspect." Cryogenic proof-testing probably would be required to validate the tanks and to give confidence in the tank welds. Meantime, he said, the problem was receiving high-level attention both at Grumman and in Houston.
Memo, Day to Apollo Program Director, "LM Descent Propellant Tank Failures," Oct. 23, 1968.
October 24Howard D. Burns, Chief of the Saturn V Test Management Office at MSFC, sent to Apollo launch operations officials at KSC a list of requirements for retesting the Saturn V following a lightning strike on the vehicle while on the pad. These requirements were to be included in the next revision of the overall test and checkout requirements documents at KSC. (Burns' action came largely as a result of discussions at the AS-503 Crew Safety Review Board meeting at KSC on August 20-21, 1968.) Burns recommended that KSC prepare a contingency plan specifying various stage and launch vehicle test and checkout procedures that would satisfy MSFC's requirements. The most immediate assessment must be the overall safety of the launch vehicle. Electronic and electrical components headed the list of specific hardware systems to be assessed.
Ltr., Burns to KSC, Attn: A. G. Smith, "AS-503-10 Launch Vehicle Test and Retest Requirements Following a Lightning Strike on the Saturn V Launch Vehicle/LUT/MSS," Oct. 24, 1968, with encl., same subj.
October 26In a memorandum for the record, MSC's Apollo LM Program Manager C. H. Bolender reviewed results of the receiving inspection performed on LM-4 at KSC on October 21. Only 59 valid "crabs" were reported, 44 of them by Grumman's receiving personnel. None of the discrepancies noted involved major hardware damage or serious procedural faults. Significant progress had been made in reducing receiving discrepancies between LM-3 and LM-4. This improvement Bolender attributed to the addition of surveillance inspectors at Grumman and to the emphasis being placed on quality control by the resident ASPO personnel at Bethpage.
Memo for Record, Bolender, "Review of LM-4 Receiving Inspection at KSC," Oct. 26, 1968.
October 28MSC Apollo Spacecraft Program Office Manager George M. Low deleted the requirement for a short static-firing of the Apollo 8 service module reaction control system on the pad before launch (the so-called "burp" firing). He took this move in line with a recommendation from NASA Apollo Program Director Samuel C. Phillips and in light of the nominal performance of the RCS during the Apollo 7 flight. By thus eliminating the burp firings - and not allowing any contact of the system's hypergolic propellants - the spacecraft could be maintained in a loaded condition through the December and January launch windows and gain the maximum launch flexibility for the Apollo 8 flight. (Decisions not to static-fire the RCS systems on spacecraft following 103 had been made some time earlier.)
TWX, Phillips to Low, "Apollo 8 Pre-Launch Burp Firing," Oct. 25, 1968; ltr., Low to Phillips, Oct. 28, 1968.
October 31NASA Apollo Program Director Samuel C. Phillips officially designated the AS-504 and AS-505 missions as Apollo 9 and Apollo 10.
TWX, Phillips, NASA Hq., to KSC, MSFC, and MSC, "Apollo Mission Designations," Oct. 31.
November 7The Configuration Control Board had decided in favor of an informal crew log for each Apollo spacecraft, ASPO Manager George M. Low informed MSC Director of Flight Crew Operations Donald K. Slayton. The log would be an unofficial document kept by consulting pilots at the spacecraft contractor plants during checkout and test of the vehicles and by the flight crew support team at KSC. Although not intended to replace other, more formal procedures for recording hardware discrepancies, the log would contain such items as switching anomalies, meter bias, and what Low termed "bona fide 'ghosts'" which had no reasonable engineering explanation, as well as audible and visual "idiosyncrasies" in spacecraft operation.
Memo, Low to Slayton, "Spacecraft crew log," Nov. 7, 1968.
November 8ASPO Manager George M. Low asked Rocco A. Petrone, Launch Operations Director at KSC, to set up a special task team to review all paperwork and to inspect visually all hardware, to ensure proper spacecraft deployment during the Apollo 8 flight. Apollo 8 contained a novel set of mechanical and electrical interfaces (CSM, LTA-B lunar module dummy, launch adapter, and Saturn V vehicle), Low observed. Furthermore, concern about these complex interfaces had increased because one of the adapter panels on Apollo 7 had not opened properly. What Low - as well as MSC Director Robert R. Gilruth - desired foremost was to preclude repetition of another situation such as had occurred during the Gemini IX mission, when the shroud panels covering the Agena target vehicle had only partially deployed and had produced the "angry alligator" that forced cancellation of docking plans on that earlier flight.
Ltr., Low to Petrone, Nov. 8, 1968.
November 12The Apollo Crew Safety Review Board met to assess land landing of the CSM in the area of the launch site if a flight were aborted just before launch or during the initial phase of a flight. In general the Board was satisfied with overall planned recovery and medical operations. The only specific item to be acted on was some means of purging the interior of the spacecraft to expel any coolant or propellant fumes that might be trapped inside the cabin. The Board was also concerned about the likelihood of residual propellants trapped inside the vehicle even after abort sequence purging, a problem that MSC secured assistance from both the Ames and Lewis Research Centers to solve. At the Board's suggestion, MSC's Crew Systems Division also investigated the use of a helmet liner for the astronauts to prevent head injury upon impact. Finally, the Board recommended continued egress training with fully suited crews, including some night training.
Memo, David B. Pendley, MSC Flight Control Div., to ASPO Manager, "Land landing in the launch site area," Nov. 18, 1968.
November 13ASPO Manager Low asked Aaron Cohen, one of his staff assistants, to lead an investigation to determine detrimental effects of moisture on the strength of the bonded covering of the launch adapter structure. His action stemmed directly from a presentation the same day by James A. Chamberlin to the Structures Advisory Board explaining the adapter failure on Apollo 6. Moisture in the adapter not only raised the pressures generated by heating during the boost phase of the flight through the atmosphere, but it also weakened the structural bonding either directly or by hampering venting through the holes in the honeycomb material. Low asked Cohen to take precautions that no water be allowed to enter the adapter. All joints in the material should be sealed with a waterproof tape even before the countdown demonstration test and should remain on the vehicle throughout the flight, so that the adapter would absorb no moisture even if it rained during the final count before launch. On the other hand, the tape must then withstand boost phase heating and must not impair spacecraft separation and panel jettisoning. (North American Rockwell, in compliance with CCBD, August 10, 1968, Master Change Record 7727, modified the SLA panels by drilling vent holes in the inner skin of the panels of all subsequent SLAs to allow release of moisture during ascent. These holes were to be kept sealed until immediately before launch to avoid collection of moisture in the honeycomb.)
Memo, Low to Cohen, "Verification of spacecraft/LM adapter," Nov. 13, 1968.
November 19Martin L. Raines, MSC's Manager at the White Sands Test Facility, recommended to ASPO Manager George M. Low that he issue official direction to the two spacecraft contractors, North American Rockwell and Grumman, governing the phasedown of operations at the engine test site. Early action was needed, Raines said, for proper contractual action on the phasedown and for proper disposition of equipment and supplies. This action signaled the end of the long and difficult supportive development effort to prove out the Apollo spacecraft rocket engines for flight.
Memo, Raines to ASPO Manager, "WSTF Phasedown Plan," Nov. 19, 1968.
November 22Howard W. Tindall, Jr., Chief of Apollo Data Priority Coordination within ASPO, reported an operational system problem aboard the LM. To give a returning Apollo crew an indication of time remaining to perform a landing maneuver or to abort, a light on the LM instrument panel would come on when about two minutes worth of propellants remained in the descent propellant system tanks with the descent engine running at 25-percent thrust. The present LM weight and descent trajectory were such that the light would always come on before touchdown. The only hitch, said Tindall, was that the signal was connected to the spacecraft master alarm. "Just at the most critical time in the most critical operation of a perfectly nominal lunar landing mission, the master alarm with all its lights, bells, and whistles will go off." Tindall related that some four or five years earlier, astronaut Pete Conrad had called the arrangement "completely unacceptable . . . but he was probably just an Ensign at the time and apparently no one paid any attention." If this "is not fixed," Tindall said, "I predict the first words uttered by the first astronaut to land on the moon will be 'Gee whiz, that master alarm certainly startled me.'" Tindall recommended either rerouting the signal wiring to bypass the alarm or cutting the signal wire and relying solely on the propellant gauges to assess flight time remaining.
Memo to distr., Tindall, "LM DPS low level light fixing," Nov. 22, 1968.
November 22In a memorandum for the record, ASPO Manager George M. Low summarized results of November 19 and 22 meetings on procedures for astronaut training runs with the Apollo extravehicular mobility unit (EMU) under simulated space conditions. The runs would be in the two vacuum test chambers of the Center's Space Environment Simulation Laboratory. MSC Director Robert R. Gilruth had attended the meetings. Training runs were always to be preceded by a run also under altitude conditions and using a gas umbilical from the life support system of the facility itself. Although connected to the crewman, the facility umbilical would not be used as a gas supply under normal test conditions. For the final training run, the astronaut would wear a complete flight-configured EMU without any other link with the facility. Although several participants objected that training runs using the EMU alone ran greater risk than normal in chamber tests, the decision to conduct the exercises using the all-up flight configuration was reaffirmed.
Memo for Record, Low, "EMU activities in the SESL," Nov. 22, 1968.
November 22NASA Associate Administrator for Manned Space Flight George E. Mueller reviewed for NASA Acting Administrator Thomas O. Paine the development of the Apollo service propulsion system (SPS) engine. (Earlier, Paine had asked whether the SPS engine had ever failed to fire during all of this developmental program.) Mueller reported that a review of the test history showed that no complete flight-configuration engine had ever failed to fire. In fact, during the entire development program (comprising some 3,200 engine starts and more than 90,000 seconds of firing time ) only four engines had failed to start. In all of these cases, the cause of the ignition failures could be traced to faulty ground support equipment or to inadequate or improper operational procedures. No engine failure could be attributed solely to the SPS engine itself. Mueller's response to Paine - with obvious overtones for the upcoming Apollo 8 circumlunar mission - bespoke a supreme confidence in the safety and reliability of the all-important main engine of the spacecraft.
Memo, Mueller to Acting Administrator, "Response to Question on Apollo Service Propulsion System Engine," Nov. 22, 1968.
November 27The LM-11 midsection assembly collapsed in the assembly jig during the bulkhead prefitting stage of construction at Grumman. The structure buckled when the bulkheads, which had just been prefitted and drilled, were removed to permit deburring the drilled holes. Jig gates that were supposed to hold up the assembly were not in position, nor was the safety line properly installed. The structure was supported by hand. Damage to the skin of the structure was not severe, although a small radius bend was put in one of the upper skins.
Memo, Samuel A. Gentile, Bethpage RASPO Contracting Officer, to distr., "Report of Damage of LM-11 Midsection Assembly during Manufacturing Phase, this date," Nov. 27, 1968.
November 27The need to flight-test manual control of the light LM ascent configuration had been discussed at the October 15 MSC Flight Program Review, MSC Director Robert R. Gilruth informed NASA Apollo Program Director Samuel C. Phillips. There was an implication that a control problem could exist for this configuration. Gilruth said he had stated that MSC should be able to establish manual control handling qualities of the LM through proper simulation and be confident about the adequacy of the control system.
Subsequently, Gilruth had reviewed the operating characteristics of the LM control system and the status of the simulation program related to manual control of the light ascent stage during docking. He said that the most demanding requirement for precision manual attitude control was the docking maneuver. Docking control had been simulated extensively at MSC, Grumman, and LaRC using functional representation of the control system and these simulations established the capability of docking the LM well within the specified docking criteria. In addition, other LM control tasks had been simulated at MSC and Grumman, and the LM was found to have satisfactory handling qualities for all manual control tasks.
Ltr., Gilruth to Phillips, "Manual Control of the Light Lunar Module Ascent Configuration," Nov. 27, 1968.