The Large Launch Vehicle Planning Group (Golovin Committee) notified the Marshal! Space Flight Center (MSFC), Langley Research Center, and the Jet Propulsion Laboratory (JPL) that the Group was planning to undertake a comparative evaluation of three types of rendezvous operations and direct flight for manned lunar landing. Rendezvous methods were earth orbit, lunar orbit, and lunar surface. MSFC was requested to study earth orbit rendezvous, Langley to study lunar orbit rendezvous, and JPL to study lunar surface rendezvous. The NASA Office of Launch Vehicle Programs would provide similar information on direct ascent. Additional Details: here....

The NAA spacecraft Statement of Work was revised to include the requirements for the lunar excursion module (LEM) as well as other modifications. The LEM requirements were identical with those given in the LEM Development Statement of Work of July 24.

The command module (CM) would now be required to provide the crew with a one-day habitable environment and a survival environment for one week after touching down on land or water. In case of a landing at sea, the CM should be able to recover from any attitude and float upright with egress hatches free of water. Additional Details: here....

Apollo Spacecraft Project Office requested NAA to perform a study of command module-lunar excursion module (CM-LEM) docking and crew transfer operations and recommend a preferred mode, establish docking design criteria, and define the CM-LEM interface. Both translunar and lunar orbital docking maneuvers were to be considered. The docking concept finally selected would satisfy the requirements of minimum weight, design and functional simplicity, maximum docking reliability, minimum docking time, and maximum visibility.

The mission constraints to be used for this study were :

• The first docking maneuver would take place as soon after S-IVB burnout as possible and hard docking would be within 30 minutes after burnout.
• The docking methods to be investigated would include but not be limited to free fly-around, tethered fly-around, and mechanical repositioning.
• The S-IVB would be stabilized for four hours after injection.
• There would be no CM airlock. Extravehicular access techniques through the LEM would be evaluated to determine the usefulness of a LEM airlock.
• A crewman would not be stationed in the tunnel during docking unless it could be shown that his field of vision, maneuverability, and communication capability would substantially contribute to the ease and reliability of the docking maneuver.
• An open-hatch, unpressurized CM docking approach would not be considered.
• The relative merit of using the CM environmental control system to provide initial pressurization of the LEM instead of the LEM environmental control system would be investigated.

The Amour Research Foundation reported to NASA that the surface of the moon might not be covered with layers of dust. The first Armour studies showed that dust particles become harder and denser in a higher vacuum environment such as that of the moon, but the studies had not proved that particles eventually become bonded together in a rocket substance as the vacuum increases.

MSC released a sketch of the space suit assembly to be worn on the lunar surface. It included a portable life support system which would supply oxygen and pressurization and would control temperature, humidity, and air contaminants. The suit would protect the astronaut against solar radiation and extreme temperatures. The helmet faceplate would shield him against solar glare and would be defrosted for good visibility at very low temperatures. An emergency oxygen supply was also part of the assembly.

Four days earlier, MSC had added specifications for an extravehicular suit communications and telemetry (EVSCT) system to the space suit contract with Hamilton Standard Division of United Aircraft Corporation. The EVSCT system included equipment for three major operations:

1. Full two-way voice communication between two astronauts on the lunar surface, using the transceivers in the LEM and CM as relay stations.
2. Redundant one-way voice communication capability between any number of suited astronauts.
3. Telemetry of physiological and suit environmental data to the LEM or CM for relay to earth via the S- band link.

Grumman and NASA announced the selection of four companies as major LEM subcontractors:

1. Rocketdyne for the descent engine
2. Bell Aerosystems Company for the ascent engine
3. The Marquardt Corporation for the reaction control system
4. Hamilton Standard for the environmental control system

The first meeting of the LEM Flight Technology Systems Panel was held at MSC. The panel was formed to coordinate discussions on all problems involving weight control, engineering simulation, and environment. The meeting was devoted to a review of the status of LEM engineering programs.

Grumman studied the possibility of using the portable life support system lithium hydroxide cartridges in the LEM environmental control system, and determined that such common usage was feasible. This analysis would be verified by tests at Hamilton Standard.

Grumman authorized Hamilton Standard to begin development of the environmental control system (ECS) for the LEM. The cost-plus-incentive-fee contract was valued at $8,371,465. The parts of the ECS to be supplied by Hamilton Standard were specified by Grumman.

MSC directed Grumman to schedule manned environmental control system (ECS) development tests, using a welded-shell cabin boilerplate and air lock. At about the same time, the company was also requested to quote cost and delivery schedule for a second boilerplate vessel, complete with prototype ECS. Although this vessel would be used by the MSC Crew Systems Division for in-house investigation and evaluation of ECS development problems, its major purpose was to serve as a tool for trouble-shooting during the operational phase.

MSC's Space Environment Division (SED) recommended (subject to reconnaissance verification) 10 lunar landing areas for the Apollo program:

1. 36 degrees 55' E. 1 degree 45' N.
2. 31 degrees E. 0 degrees N.
3. 28 degrees 22' E. 1 degree 10' N.
4. 24 degrees 10' E. 0 degrees 10' N.
5. 12 degrees 50' E. 0 degrees 20' N.
6. 1 degree 28'W. 0 degrees 30' S.
7. 13 degrees 15' W. 2 degrees 45' N.
8. 28 degrees 15' W. 2 degrees 45' N.
9. 31 degrees 30' W. 1 degree 05' S.
10. 41 degrees 30'W. 1 degree 10' S.

Bendix Products Aerospace Division was awarded a 99973 contract by MSC to study crushable aluminum honeycomb, a lightweight, almost non-elastic, shock-absorbing material for LEM landing gears. Bendix would test the honeycomb structures in a simulated lunar environment.

Representatives of Grumman, MSC's Instrumentation and Electronics Systems Division, ASPO, and Resident Apollo Spacecraft Program Office (RASPO) at Bethpage met at Grumman to plan the LEM's electrical power system. The current configuration was composed of three fuel cell generators with a maximum power output of 900 watts each, spiking stabilizing batteries, one primary general-purpose AC inverter, and a conventional bus arrangement. To establish general design criteria, the primary lunar mission of the LEM-10 vehicle was analyzed. This "critical" mission appeared to be the "worst case" for the electrical power system and established maximum power and usage rate requirements.

Those attending the meeting foresaw a number of problems:

• Grumman allowed only 10 percent margin for all contingencies and errors in energy requirements.
• Fuel cells and cryogenic fuels needed testing in a simulated space environment.
• Grumman depended upon its subcontractors to develop component testing procedures.
• Optimum power supply modes and motors for the environmental control system were still to be selected.
• "Essential loads" needed standardizing to allow the proper bus loading structure.
• Proper charging rates and equipment for the portable life support system extravehicular suit batteries needed to be selected.

At an Apollo Program Review held at MSC, Maxime A. Faget reported that Crew Systems Division had learned that the metabolic rate of a man walking in an unpressurized suit was twice that of a man in everyday clothes. When the suit was pressurized to 1.8 newtons per square centimeter (3.5 psi), the rate was about four times as much. To counteract this, a watercooled undergarment developed by the British Ministry of Aviation's Royal Aircraft Establishment was being tested at Hamilton Standard. These "space-age long johns" had a network of small tubes through which water circulated and absorbed body heat. Advantages of the system were improved heat transfer, low circulating noise levels, and relatively moderate flow rates required. An MSC study on integration of the suit with the LEM environmental control system showed a possible weight savings of 9 kilograms (20 pounds).

Grumman completed an environmental control system water management configuration study and concluded that a revised design would significantly improve the probability of mission success and crew safety. This design would combine water tanks for the water management functions into one easily accessible package.

Grumman redesigned the LEM environmental control system to incorporate a replaceable lithium hydroxide cartridge with a portable life support system cartridge in parallel for emergency backup. The LEM cartridge would be replaced once during a two-day mission.

Also MSC advised Grumman that estimates of the metabolic rates for astronauts on the lunar surface had been increased. The major effect of this change was an increase in the requirements for oxygen and water for the portable life support system.

Representatives from a number of elements within MSC (including systems and structural engineers, advanced systems and rendezvous experts, and two astronauts, Edward H. White II and Elliot M. See, Jr.) discussed the idea of deleting the LEM's front docking capability (an idea spawned by the recent TM-1 mockup review). Rather than nose-to-nose docking, the LEM crew might be able to perform the rendezvous and docking maneuver, docking at the spacecraft's upper (transfer) hatch, by using a window above the LEM commander's head to enable him to see his target. Additional Details: here....

Representatives from the MSC Astronaut Office, and ASPO's Systems Engineering, Crew Systems, and Mission Planning divisions made several significant decisions on crew transfer and space suit procedures:

• Crew transfer, both pressurized and unpressurized, would be accomplished using the environmental control system umbilicals. The CM and LEM umbilicals would be designed accordingly. Crew Systems would request the necessary engineering changes.
• The requirement for "quick-don" capability for the space suit would be reevaluated by Systems Engineering people. If the probability of a rapid decompression of the spacecraft during "noncritical" mission phases was negligible, "quick-don" capability might be eliminated. This would ease several design constraints on the suit.
• The question of a crossover valve in the CM, for ventilation during open-faceplate operation, was postponed pending the decompression study and ventilation tests at Hamilton Standard.

Because of the redesign of the portable life support system that would be required, MSC directed Grumman and North American to drop the "buddy system" concept for the spacecraft environmental control system (ECS) umbilicals. The two LEM crewmen would transfer from the CM while attached to that module's umbilicals. Hookup with the LEM umbilicals, and ventilation from the LEM ECS, would be achieved before disconnecting the first set of lifelines. MSC requested North American to cooperate with Grumman and Hamilton Standard on the design of the fetal end of the umbilicals. Also, the two spacecraft contractors were directed jointly to determine umbilical lengths and LEM ECS control locations required for such transfer.

Grumman reported to MSC the results of development tests on the welding of the LEM cabin's thin-gauge aluminum alloy. The stress and corrosion resistance of the metal, Grumman found, was not lessened by environments of pure oxygen, varying temperatures, and high humidity.

MSC spelled out additional details of the LEM environmental control system (ECS) umbilical arrangements. The hoses were to be permanently bonded to the ECS; a crossover valve, to permit flow reversal, was mandatory; and a bypass relief would be added, if necessary, to prevent fan surge. Grumman was to coordinate with North American to ensure that all umbilicals were long enough for crew transfer and to determine the optimum location for the spacecraft's ECS switches.

Crew Systems Division (CSD) was proceeding with procurement of an inflight metabolic simulator in response to a request by Systems Engineering Division. The simulator would be used to support the LEM mission for SA-206 and would be compatible for use in the CM. Responsibility for the project had been assigned to the Manager of the LEM Environmental Control System Office. It was projected that the Statement of Work would be completed by January 15, 1965; the proposals evaluated by April 1; the contract awarded by June 1, 1965; the prototype delivered by April 1, 1966, with two qualified simulator deliveries by July 1, 1966.

To make room for a rendezvous study, MSC was forced to end, prematurely, its simulations of employing the LEM as a backup for the service propulsion system. Nonetheless, the LEM was evaluated in both manual and automatic operation. Although some sizable attitude changes were required, investigators found no serious problems with either steering accuracy or dynamic stability.

MSC's Systems Engineering Division (SED) requested support from the Structures and Mechanics Division in determining the existence or extent of corrosion in the coolant loops of the SM electrical power subsystem (EPS) and the CM and LEM environmental control subsystems (ECS), resulting from the use of water glycol as coolant fluid. Informal contact had been made with W. R. Downs of the Structures and Mechanics Division and he had been given copies of contractor reports and correspondence between MSC, North American, and MIT pertaining to the problem. The contractors had conflicting positions regarding the extent and seriousness of glycol corrosion.

SED requested that a study be initiated to:

1. determine the existence or extent of corrosion in the EPS and ECS coolant loops; and
2. make recommendations regarding alternate materials, inhibitors, or fluids, and other tests or remedial actions if it were determined that a problem existed.

MSC announced a realignment of specialty areas for the 13 astronauts not assigned to forthcoming Gemini missions (GT 3 through 5) or to strictly administrative positions:

Operations and Training

Edwin E. Aldrin, branch chief - mission planning

Charles A. Bassett - operations handbooks, training, and simulators

Alan L. Bean - recovery systems

Michael Collins - pressure suits and extravehicular activity

David R. Scott - mission planning and guidance and navigation

Clifton C. Williams - range operations, deep space instrumentation, and crew safety.

Project Apollo

Richard F. Gordon, branch chief - overall astronaut activities in Apollo area and liaison for CSM development

Donn F. Eisele - CSM and LEM

William A. Anders - environmental control system and radiation and thermal systems

Eugene A. Cernan - boosters, spacecraft propulsion, and the Agena stage

Roger B. Chaffee - communications, flight controls, and docking

R. Walter Cunningham - electrical and sequential systems and non-flight experiments

Russell L. Schweickart - in-flight experiments and future programs.

MSC contacted Grumman with reference to the LEM ascent engine environmental tests at Arnold Engineering Development Center (AEDC), scheduled for cell occupancy there from May 1, 1965, until September 1, 1965. It was MSC's understanding that the tests might begin without a baffled injector. It was pointed out, however, that the first test was expected to begin July 1, and since the recent baffle injector design selection had been made, time remained for the fabrication of the injector, checkout of the unit, and shipment to AEDC for use in the first test.

Since the baffled injector represented the final hardware configuration, it was highly desirable to use the design for these tests. MSC requested that availability of the injector constrain the tests and that Grumman take necessary action to ensure compliance.

The LEM Project Officer notified Grumman that the President's Scientific Advisory Committee (PSAC) had established sub-panels to work on specific technical areas, beyond the full PSAC briefings. One of the sub-panels was concerned with the environmental control subsystem, including space suits. This group desired representation from Hamilton Standard to discuss with regard to the LEM-ECS its interpretation of the reliability design requirements, its implementation through development and test phases, its demonstration of reliability, and its frank assessment of confidence in these measures. Briefing material should be available to the sub-panel by May 17, 1965, with a primary discussion meeting to be held at Hamilton Standard on May 24.

Systems Engineering Division did not concur in use of the chamber technician's suit by test subjects in AFRM 008 tests. AFRM 008 represented the only integrated spacecraft test under a simulated thermal- vacuum environment and was therefore considered a significant step in man-rating the overall system. For that reason use of the flight configuration Block I suit was a firm requirement for the AFRM 008 tests.

The same rationale would be applicable to the LEM and Block II vehicle chamber tests. Only flight configured spacecraft hardware and extravehicular mobility unit garments would be used by test subjects.

ASPO reviewed Grumman's recommendation for a combination of supercritical and gaseous modes for storing oxygen in the LEM's environmental control system (ECS). MSC engineers determined that such an approach would save only about 14.96 kg (33 lbs) over a high- pressure, all-gaseous design. Mission objectives demanded only four repressurizations of the LEM's cabin. On the basis of this criterion, the weight differential was placed at less than nine pounds.

As a result of this analysis, MSC directed Grumman to design the LEM ECS with an all-gaseous oxygen storage system.

MSC informed Grumman it believed it would be beneficial to the LEM development program for MSC to participate in the manned environmental control system tests to be conducted in Grumman's Internal Environment Simulator. The following individuals were suggested to participate: Astronaut William A. Anders or an alternate to act as a test crewman for one or more manned runs; D. Owen Goons or an alternate to act as a medical monitor for the aforementioned astronaut; and John W. O'Neill or an alternate to monitor voice communications during the test and record astronaut comments.

Donald K. Slayton, Assistant Director for Flight Crew Operations, described a potential hazard involved in crew procedures inside the LEM. Two sets of umbilicals linked the Block II space suit to the environmental control system (ECS) and to the portable life support system (PLSS). Though slight, the possibility existed that when a hose was disconnected, the valve inside the suit might not seat. In that event, gas would escape from the suit. Should this occur while the LEM was depressurized, the astronaut's life would be in jeopardy. Consequently, Slayton cautioned, it would be unwise to disconnect umbilicals while in a vacuum. This in turn imposed several mission constraints:

• PLSSs could not be recharged while the LEM was unpressurized.
• If the astronauts were planning to leave the spacecraft, they had to switch to the PLSSs and disconnect the ECS hoses before depressurizing their vehicle.
• Because the cooling circuit in the PLSS operated only in a vacuum, the crew must depressurize the LEM shortly after switching to their PLSSs.

Crew Systems Division reported that, as currently designed, the environmental control system (ECS) in the LEM would not afford adequate thermal control for an all-battery spacecraft. Grumman was investigating several methods for improving the ECS's thermal capability, and was to recommend a modified configuration for the coolant loop.

MSC ordered Grumman to propose a gaseous oxygen storage configuration for the LEM's environmental control system (ECS), including all oxygen requirements and system weights. Because no decision was yet made on simultaneous surface excursions by the crew, Grumman should design the LEM's ECS for either one-or two-man operations. And the Center further defined requirements for cabin repressurizations and replenishment of the portable life support systems. Oxygen quantities and pressures would be worked out on the basis of these ground rules.

In a series of meetings at Downey, Calif., MSC, Grumman, and North American worked out most of the interface between the two spacecraft. Among the most significant items yet unresolved were: the thermal environment of the LEM during boost; and the structural loads and bending modes between the docked spacecraft.

Structures and Mechanics Division (SMD) reported that Grumman had found two thermal problems with the LEM:

1. On the basis of current predictions, the spacecraft's skin and several antennas would overheat during the boost phase of the mission. SMD engineers, after analyzing the problem, believed that an "acceptable LEM environment" could be achieved by lessening the heat transferred from the inner panels of the adapter and by increasing that emitted by the outer panels.
2. Also, Grumman had reported that, when exposed to exhaust plumes from the SM's reaction control engines, the LEM's skin would overheat in about five seconds. "Since the LEM withdrawal . . . requires 20 to 26 sec RCS firing," SMD understated, "it is apparent that a problem exists." One suggested solution involved improved insulation.

Joseph F. Shea, ASPO Manager, established as a firm mission requirement the capability to connect the space suit to the LEM's environmental system and to the portable life support system while in a vacuum. This capability was essential for operational flexibility on the moon's surface.

Crew Systems Division (CSD) conducted a series of flight tests to determine whether the cabin layout of the LEM was suitable for crew performance in zero and one-sixth g environments. Together with its report of satisfactory results, the division made several observations that it thought "appropriate":

• CSD suggested hand grips in a number of places to aid the crew
• Additional restraints were needed to supplement the Velcro pile on the cabin floor
• Some problems with crew performance and mobility, present during one-g simulations, were absent in low- or zero-g environments (e.g., moving from one crew station to another).

Grumman completed its study of oxygen storage systems for the LEM and reviewed with MSC the company's recommendation (one 20,684-kilonewton per sq m (3,000 psi) tank in the descent stage, two 6,894-kilonewtons per sq m (1,000 psi) tanks in the ascent stage). One drawback to the design, which the Crew Systems Division termed an "apparently unavoidable bad feature," was that, by the time of the final cabin repressurization, the repressurization time would increase to about 12 minutes (though this was admittedly a conservative estimate). Although requesting more data from Grumman on temperatures and cabin pressures, the Center approved the configuration.

Crew Systems Division (CSD) completed its study on the feasibility of controlling the amount of bacteria vented from the LEM. Division researchers found that, by placing special filters in the environmental control system (ECS) of the spacecraft, emission levels could be greatly lowered. This reduction would be meaningless, however, in view of effluents from the extravehicular mobility unit (EMU) - the moon would still be contaminated by the space travelers. Because of weight penalties - and because of their dubious value - CSD recommended that bacteria filters not be added to the LEM's ECS. The Division further advised that, at present, neither the amount of bacteria emitted from the EMU nor a means of controlling this effluence was yet known.

Crew Systems Division (CSD) reported that changing the method for storing oxygen in the LEM (from cryogenic to gaseous) had complicated the interface between the spacecraft's environmental control system (ECS) and the portable life support system (PLSS). Very early, the maximum temperature for oxygen at the PLSS recharge station had been placed at 80 degrees. Recent analyses by Grumman disclosed that, in fact, the gas temperature might be double that figure. Oxygen supplied at 160 degrees, CSD said, would limit to 2½ hours the PLSS operating period. Modifying the PLSS, however, would revive the issue of its storage aboard both spacecraft.

Seeking some answer to this problem, CSD engineers began in-house studies of temperature changes in the spacecraft's oxygen. There was some optimism that Grumman's estimates would be proved much too high, and MSC thus far had made no changes either to the ECS or to the PLSS.

Grumman received approval from Houston for an all-gaseous oxygen supply system in the LEM. While not suggesting any design changes, MSC desired that portable life support systems (PLSS) be recharged with the cabin pressurized. And because the oxygen pressure in the descent stage tanks might be insufficient for the final recharge, the PLSSs could be "topped off" with oxygen from one of the tanks in the vehicle's ascent stage if necessary.

MSC requested that Grumman review the current LEM landing and docking dynamic environments to assure: (1) no loss of the abort guidance system attitude reference due to angular motion exceeding its design limit of 25 degrees per second during indicated mission phases; and (2) a mission angular acceleration environment, exceeding the gyro structural tolerances, would not be realized.

To solve the problem of controlling bacteria in the LEM's waste management system (WMS), Crew Systems Division (CSD) recommended some type of passive control rather than periodically adding a germicide to the system. CSD described two such passive techniques, both of which relied on chemicals upstream from the WMS (i.e., in the urine collection device in the space suit). MSC began studying the feasibility of this approach, and ordered Grumman also to evaluate passive control in the contractor's own investigation of the bacteriological problem.

MSC instructed North American to:

• Submit a preliminary design of Block II CSM jettisonable covers to protect the radiator and CM heatshield thermal coatings from degradation by the boost environment.
• Furnish preliminary design of nonablative reaction control system (RCS) plume heat protection to prevent SM coating degradation on Block II CSMs.
• Determine the effect on the overall SM and LEM adapter thermal design of coating degradation to a level specified by MSC and to propose design changes or mission constraints for Block I and Block II CSMs.
• Determine the effect on the SM RCS thermal design of coating degradation to the level specified by MSC and to propose design changes or mission constraints for Block I and II CSMs.

MSC was considering the use of both water and air bacteria filters in the LEM to reduce contamination of the lunar surface. Crew Systems Division (CSD) would attempt to determine by tests what percentage concentration of micro-organisms would be trapped by the filters. CSD hoped to begin limited testing in January 1966.

At an MSC meeting attended by ASPO, CSD, and Lunar Sample Receiving Laboratory representatives, it was decided that the following directions would be sent to Grumman:

1. In order to prolong the prevention of lunar surface contamination, provisions should be made to store urine and lithium hydroxide canisters in the descent stage; and
2. the portable life support systems and associated extravehicular mobility items should be dumped onto the lunar surface after all lunar surface exploration had been completed.

The following responsibilities were transferred from MIT to AC Electronics:

1. design responsibility for the Block I and Block II eyepiece compartment;
2. responsibility for all Block II and LEM system coatings which were exposed to the spacecraft or space environment; and
3. design responsibility for the LEM navigation base.

A potential problem still existed with the boost environment for the LEM and the associated spacecraft-LEM-adapter (SLA) thermal coating. Systems Engineering Division authorized North American to proceed with implementation of an SLA thermal coating to meet the currently understood SLA requirements. Grumman would review the North American study in detail for possible adverse impact on the LEM and would negotiate with MSC.

John D. Hodge, Chief of MSC's Flight Control Division, proposed that time-critical aborts in the event of a service propulsion system failure after translunar injection (TLI; i.e., insertion on a trajectory toward the moon) be investigated. Time-critical abort was defined as an abort occurring within 12 hours after TLI and requiring reentry in less than two days after the abort.

He suggested that if an SPS failed the service module be jettisoned for a time-critical abort and both LEM propulsion systems be used for earth return, reducing the total time to return by approximately 60 hours. As an example, if the time of abort was 10 hours after translunar injection, he said, this method would require about 36 hours; if the SM were retained the return time would require about 96 hours.

He added that the LEM/CM-only configuration should be studied for any constraints that would preclude initiating this kind of time-critical abort. Some of the factors to be considered should be:

1. maximum time the LEM environmental control system could support two or three men on an earth return;
2. maximum time the CM electrical system could support minimum power-up condition;
3. time constraints on completely powering down the CM and using the LEM systems for support;
4. effects on planned landing areas from an open loop reentry mode;
5. stability of the LEM/CM configuration during the descent and ascent propulsion burns;
6. total time to return using the descent propulsion system only or both the LEM's descent propulsion system and ascent propulsion system; and
7. communications with Manned Space Flight Network required to support this abort.

The Grumman-directed Apollo Mission Planning Task Force reported on studies of abort sequences for translunar coast situations and the LEM capability to support an abort if the SM had to be jettisoned. The LEM could be powered down in drifting flight except for five one-hour periods, and a three-man crew could be supported for 57 hours 30 minutes. It was assumed that all crewmen would be unsuited in the LEM or tunnel area and that the LEM cabin air, circulated by cabin fans, would provide adequate environment.

A series of actions on the LM rendezvous sensor was summarized in a memo to the MSC Apollo Procurement Branch. A competition between LM rendezvous radar and the optical tracker had been initiated in January 1966 after discussion by ASPO Manager Joseph F. Shea, NASA Associate Administrator for Manned Space Flight George E. Mueller, and MSC Guidance and Control Division Chief Robert C. Duncan. On May 13, RCA and Hughes Aircraft Go. made presentations on the rendezvous radar optical tracker. The NASA board that heard the presentations met for two days to evaluate the two programs and presented the following conclusions:

1. both sensors could meet the difficult environmental requirements of the lunar mission with near specification performance,
2. the tracker had several possible specification deviations,
3. optical production training represented a difficult schedule problem at Hughes, and
4. either sensor could be produced in time to meet LM and program schedules.

Donald K. Slayton said there was some question about including extravehicular activity on the AS-503 mission, but he felt that, to make a maximum contribution to the lunar mission, one period of EVA should be included. Slayton pointed out that during the coast period (simulating lunar orbit) in the current flight plan the EVA opportunity appeared best between hour 90 and hour 100. Additional Details: here....

An MSC meeting selected a Flight Operations Directorate position on basic factors of the first lunar landing mission phase and initiated a plan by which the Directorate would inform other organizations of the factors and the operational capabilities of combining them into alternate lunar surface mission plans.

Flight Operations Director Christopher C. Kraft, Jr., conducted the discussion, with Rodney G. Rose, Carl Kovitz, Morris V. Jenkins, William E. Platt, James E. Hannigan, Bruce H. Walton, and William L. Davidson participating.

The major factors (philosophy) identified at the meeting were:

• "The astronauts should be provided with an extravehicular (EVA) timeline framework and objectives and then be given real time control of their own activities. This approach should better accommodate the first lunar surface unknowns than if rigorous activity control were attempted from earth."
• "The LM should always be in a position to get back into lunar orbit in the minimum time. Specifically the merits and feasibility of maintaining the LM platform powered up and aligned should be evaluated. Any other LM systems requiring start up time after powering down should be identified."
• "The constraints affecting the minimum time required to turn around and launch after LM landing and the time line should be determined. This time was estimated to two CSM orbits. The effects of Manned Space Flight Network (MSFN) support should be considered."
• The first EVA should be allocated to LM post landing inspection, immediate lunar sample collection, lunar environment familiarization, photographic documentation, and astronaut exploration prerogatives. Any second EVA would include deployment of ALSEP (Apollo Lunar Surface Experiments Package) and a more systematic geological survey. Therefore, a mission nominally planned for only one EVA would not have to include an ALSEP in the payload. Any flight operations benefits resulting from deletion of the ALSEP weight and deployment operations (such as replacing weight with more fuel) must be determined."

Possible hazards to the crew in the lunar module thermal vacuum test program (using LTA-8) were pointed up in a memorandum to Manager, ASPO, and Director of Engineering and Development from the Director of Flight Crew Operations. Manning procedures required crewmen to make numerous hard vacuum transfers between the Space Environment Simulation Laboratory's environmental control system (ECS) umbilicals and the LM environmental control system hoses. Also, during the manning operations the crewmen would be on the LM-ECS with the cabin depressurized. In the configuration in use, if one of the crewmen lost his suit integrity, there would be no protection for the other man. Because of these hazardous conditions the following actions were requested:

1. provide equipment to make vacuum transfers of oxygen hoses acceptably safe; and
2. change the LTA-8 vehicle ECS so that one crewman was protected if the other lost suit integrity in a vacuum ambient.

MSC's Engineering and Development (E&D) Directorate recommended that the Apollo CM be provided with a foam fire extinguisher. E&D also recommended that the LM be provided with a water nozzle for extinguishing open fires and that cabin decompression be used to combat fires behind panels. An aqueous gel (foam) composition fire extinguisher was considered most appropriate for use in the CM because hydrogen in the available water supply could intensify the fire, water spray could not reach fires behind panels, and a shirt-sleeve environment was preferred. E&D further recommended that development of a condensation nuclei indicator be pursued as a flight fire detection system, but that it not be made a constraint on the Apollo program. ASPO Manager George M. Low concurred with the recommendations September 28 and MSC Director Robert R. Gilruth concurred October 7.

On October 26, the Director of Flight Crew Operations stated that his Directorate was formulating and implementing a training program for flight crews to give them experience in coping with fire in and around the spacecraft. "In total, the crew training for cockpit fires will consist of: Review of BP 1224 and M-6 'burn test' film; demonstration briefings on the fire extinguishers and their most effective use; procedural practice simulating cockpit fire situations in conjunction with one 'g' spacecraft/mockup/Apollo Mission Simulator walkthroughs and in the egress trainer placed in the altitude chamber; and as a part of the overall launch pad emergency and evacuation procedures training at the fire service training area at KSC."

Because of many questions asked about spacecraft weight changes in the spacecraft redefinition, ASPO Manager George M. Low prepared a memo for the record, indicating weights as follows:

Lunar Module Significant Weight Changes Lunar module injected weight status March 1, 1967 (ascent and descent less propellant) - 4039.6 kg

• Material substitution +23.1;
• decrease clamps and potting, -4.5;
• government furnished equipment changes (pressure garment assembly, portable life support system, oxygen purge system), +68;
• plume heating and "fire-in-the-hole" protection, +59.8;
• redesign umbilical hoses, +2.2;
• revised oxygen and water requirements, +19.5;
• provision for ALSEP removal, +11.3;
• increasing crack resistance of webs, +13.6;
• additional wiring to provide redundant circuits, +4.9;
• fuel cask and support increase, +14.9;
• guidance and navigation equipment, +3.1;
• instrumentation, +9.9;
• communications, +1.8;
• miscellaneous changes, +2.2.

Lunar module injected weight status September 22, 1967 - 4270.0 kg

Command Module Significant Weight Changes Command module injected weight status March 1, 1967 - 5246.7 kg

• New hatch, +114.7;
• environmental control system and weight management system changes, +103.4;
• instrumentation and electrical power, +48;
• wiring and tubing protection, +44.4;
• crew compartment materials and crew equipment, +101.6;
• forward heatshield separation, +13.6;
• earth landing system (larger drogues), +21.7;
• miscellaneous structural changes, +26.7;
• ballast for lift-over-drag ratio of 0.35, +175;
• other, +19.5.
• Reductions - transfer of portable life support system to LM,-31.2;
• reduced ballast for lift-over-drag ratio of 0.28, -142.8;
• other MSC weight reductions, -61.6.

Command module injected weight status September 22, 1967 - 5679.8 kg

An MSC meeting discussed environmental acceptance testing of Apollo spacecraft at the vehicle level. The meeting was attended by representatives of OMSF, MSC, and General Electric. Lad Warzecha presented results of a GE analysis of ground- and flight-test failures in a number of spacecraft programs. GE had concluded that a significant number of failures could be eliminated through complete vehicle environmental (vibration and thermal vacuum) acceptance testing and recommended such testing be included in the CSM and LM programs. James A. Chamberlin, MSC, presented a critique of the GE recommendations and found fault with the statistical approach to the GE analysis, indicating that each flight failure would have to be considered individually to reach valid conclusions. After considerable discussion ASPO Manager George M. Low said that he had reached the following conclusions:

1. Adequate environmental screening at the piece part and component level was essential. Significant steps in this direction had been taken by requiring a wider use of high-reliability parts and by imposing higher vibration levels in black box acceptance testing.
2. Vehicle-level environmental acceptance testing was not applicable to the CSM or LM spacecraft. This conclusion was reached because it was not possible to vibrate, or otherwise excite, any of the Apollo spacecraft in a way to give meaningful vibration levels at most internal spacecraft locations.

A LM prelaunch atmosphere selection and repressurization meeting was held at MSC, attended by representatives of MSC, MSFC, KSC, North American Rockwell, and Grumman. The rationale for MSC selection of 100 percent oxygen as the LM cabin launch atmosphere was based on three factors: use of other than 100 percent oxygen in the LM cabin would entail additional crew procedural workloads at transposition and docking; excessive risk to crew due to depletion of the CM emergency oxygen consumables would be added; and it would require use of 2.7 kilograms of onboard CM oxygen. Two problems were identified with use of 100 percent oxygen in the LM cabin at launch: LM cabin flammability on the pad and LM venting oxygen into the SLA during boost. If air were used in the LM cabin at launch and the LM vent valve opened during boost, the full CM stored-oxygen capacity would be required to pressurize the LM and LM tunnel for umbilical mating. For a lunar mission, this situation would be similar to that before lunar orbital insertion, but would subject the crew to a condition of no stored oxygen for an emergency. For an earth-orbital mission this situation would be objectionable because CM stored oxygen would be lacking for an emergency entry into the atmosphere.

ASPO Manager George M. Low advised top officials in Headquarters, MSFC, and KSC that he was recommending the use of 100 percent oxygen in the cabin of the LM at launch. MSC had reached this decision, Low said, after thorough evaluation of system capabilities, requirements, safety, and crew procedures. The selection of pure oxygen was based on several important factors: reduced demand on the CSM's oxygen supply by some 2.7 kilograms; simplified crew procedures; the capability for immediate return to earth during earth-orbital missions in which docking was performed; and safe physiological characteristics. All of these factors, the ASPO Chief stated, outweighed the flammability question. Because the LM was unmanned on the pad, there was little electrical power in the vehicle at launch and therefore few ignition sources. Further, the adapter was filled with inert nitrogen and the danger of a hazardous condition was therefore minimal. Also, temperature and pressure sensors inside the LM could be used for fire detection, and fire could be fought while the mobile service structure was in place. As a result, Low stated, use of oxygen in the LM on the pad posed no more of a hazard than did hypergolics and liquid hydrogen and oxygen.

ASPO Manager George M. Low requested Joseph N. Kotanchik to establish a task team to pull together all participants in the dynamic analysis of the Saturn V and boost environment. He suggested that Donald C. Wade should lead the effort and that he should work with George Jeffs of North American Rockwell, Tom Kelly of Grumman and Wayne Klopfenstein of Boeing, and that Lee James of MSFC could be contacted for any desired support or coordination. The team would define the allowable oscillations at the interface of the spacecraft-LM adapter with the instrument unit for the existing Block II configuration, possible changes in the hardware to detune the CSM and the LM, and the combined effects of pogo and the S-IC single-engine-out case. Low also said he was establishing a task team under Richard Colonna to define a test program related to the same problem area and felt that Wade and Colonna would want to work together.

In response to a letter from Apollo Program Director Samuel C. Phillips concerning proposed revisions of the first lunar landing mission plan, MSC Director Robert R. Gilruth presented MSC's position on the three major topics:

1. deletion of the lunar geology investigation (LGI) and the Apollo Lunar Surface Experiments Package (ALSEP),
2. television coverage, and
3. extravehicular excursion.