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Those attending the meeting foresaw a number of problems:
During this same week, Pratt and Whitney Aircraft tested a LEM-type fuel cell for 400 hours without shutdown and reported no leaks.
The astronauts' review was held on October 5 and 6. It included demonstrations of entering and getting out of the LEM, techniques for climbing and descending the ladder, and crew mobility inside the spacecraft. The general inspection was held on the 7th and the Review Board met on the 8th. Those attending the review used request for change (RFC) forms to propose spacecraft design alterations. Before submission to the Board, these requests were discussed by contractor personnel and NASA coordinators to assess their effect upon system design, interfaces, weight, and reliability.
The inspection categories were crew provisions; controls, displays, and lighting; the stabilization and control system and the guidance and navigation radar; electrical power; propulsion (ascent, descent, reaction control system, and pyrotechnics ; power generation cryogenic storage and fuel cell assemblies ; environmental control; communications and instrumentation; structures and landing gear; scientific equipment; and reliability and quality' control. A total of 148 RFCs were submitted. Most were aimed at enhancing the spacecraft's operational capability; considerable attention also was given to quality and reliability and to ground checkout of various systems. No major redesigns of the configuration were suggested.
As a result of this review, the Board recommended that Grumman take immediate action on those RFC's which it had approved. Further, the LEM contractor and MSC should promptly investigate those items which the Board had assigned for further study. On the basis of the revised M-5 configuration, Grumman could proceed with LEM development and qualification. This updated mockup would be the basis for tooling and fabrication of the initial hardware as well.
At about the same time, Grumman was analyzing the auxiliary battery requirements of the spacecraft. The contractor found that, under the worst possible conditions (i.e., lunar abort), the LEM would need about 1,700 watt-hours of auxiliary power. Accordingly, Grumman recommended one 1,700 watt-hour or two 850 watt-hour batteries (23 and 29.5 kg (50 and 65 lbs), respectively) in the spacecraft's ascent stage.
During November, however, Hamilton Standard and Crew Systems Division (CSD) engineers advised the Instrumentation and Electronic Systems Division (IESD) that the PLSS's power requirements had increased to about 200 watt-hours. (CSD had jurisdiction over the PLSS, including battery requirements; IESD was responsible for the charger.) Hamilton Standard placed most of the blame on the cooling pump motor, which proved far less efficient than anticipated, as well as on the addition of biosensor equipment. ASPO Manager Joseph F. Shea, reviewing the company's explanation, commented that "this says what happened . . . but is far from a justification - this is the type of thing we should understand well enough to anticipate." "How can this happen," he wondered, ". . . in an area which has been subjected to so much discussion and delay?"
Representatives from Grumman and Hamilton Standard, meeting at MSC on December 17, redefined PLSS battery and charging requirements, and Grumman was directed to proceed with the development of the battery charger. This episode was accompanied by some sense of urgency, since Grumman had to have firm requirements before the end of year to prevent a schedule slippage.
During the latter part of the month, Crew Systems Division (CSD) engineers also looked into the several approaches. In contrast to Grumman, CSD calculated that, at most, an all-gaseous system would be but 4.08 kg (9 lbs) heavier than a supercritical one. CSD nonetheless recommended the former. It was felt that the heightened reliability, improved schedules, and "substantial" cost savings that accompanied the all-gaseous approach offset its slim weight disadvantage.
During late April, MSC ordered Grumman to adopt CSD's approach (gaseous systems in both stages of the vehicle). (Another factor involved in this decision was the lessened oxygen requirement that followed substitution of batteries for fuel cells in the LEM.)
North American's Space and Information Systems Division would continue development at Pratt & Whitney on the CSM fuel cell for 18 months at a cost not to exceed $2.5 million, to ensure meeting the 400-hour lifetime requirement of the CSM system.
MSC would contract directly with Pratt & Whitney for CSM cell development followed by complete CSM module testing for a 1,000-hour CSM module at a cost of approximately $2.5 million. Grumman was scheduled to propose to ASPO their battery contractor selection on April 29, 1965.
TWX, James L. Neal, MSC, to GAEC, Attn: R. S. Mullaney. April 30, 1965.
During the Month
Grumman reported two major problems with the LEM's descent engine:
Phillips suggested to ASPO Manager Joseph F. Shea that since MSFC had much experience in the design, development, and operational aspects of battery systems, it was important to use their experience and recommended MSFC be contacted if such action had not already occurred.
In his May 31 letter to Phillips, Low enclosed Grumman's reply and said that, in his opinion, Grumman's practice was acceptable because
The team's preliminary report was based on data received and observations of the LM at Grumman that indicated the interface of the RTG, LM, and spacecraft-LM adapter (SLA) presented a potential problem to the Apollo mission. The most serious hazard was the presence of the 530-640 K (500-700 degrees F) RTG fuel cask in the space between the LM and the SLA, where leaks were possible during fuel unloading or in the mechanical joints of the LM fuel system.
Plans were to fuel the LM four days before launch and to pressurize the LM fuel system at T (time of launch) minus 16 hours. The RTG fuel element was to be loaded into the graphite cask, which was mounted on the LM at T minus 12 hours and the system secured. All work would be completed on the ALSEP by T minus 10 hours. If a condition occurred that required unloading fuel from the LM after installation of the fuel element in the cask, the hot cask would be a partial barrier to reaching one of the fuel unloading points and also would be a potential fire hazard. No mechanism was available to remove the entire cask system rapidly. Other potential problems were: