At STG the Apollo Technical Liaison Group for Human Factors discussed the proposed outline for the spacecraft specification. Its recommendations included:
NAA determined that preliminary inflight nuclear radiation instrumentation would consist of an onboard system to detect solar x-ray or ultraviolet radiation and a ground visual system for telemetering solar flare warning signals to the command module. The crew would have eight to ten minutes warning to take protective action before the arrival of solar flare proton radiation.
NAA developed a concept for shock attenuation along the command module Y-Y axis by the use of aluminum honeycomb material. Cylinders mounted on the outboard edge of the left and right couches would extend mechanically to bear against the side compartment walls.
NAA began compiling a list of command module materials to be classified selectively for potentially toxic properties. These materials would be investigated to determine location (related to possible venting of gases), fire resistance, exposure to excessive temperatures, gases resulting from thermal decomposition, and toxicity of gases released under normal and material-failure conditions. Although a complete examination of every material was not feasible, materials could be grouped according to chemical constituency and quantity of gases released.
Two NAA analyses showed that the urine management system would prevent a rise in the command module humidity load and atmospheric contamination and that freeze-up of the line used for daily evacuation of urine to the vacuum of space could be prevented by proper orificing of the line.
The command module waste management system analysis, including a new selection valve, revised tubing lengths, odor removal filter, and three check valves, was completed by NAA for a 5 psia pressure. There was only a small change in the flow rates through the separate branches as a result of the change to 5 psia.
Incandescent lamps would be used for floodlighting the command module because they weighed less than fluorescent lamps and took up less space while increasing reliability and reducing system complexity. A 28- volt lamp was most desirable because of its compatibility with the spacecraft 28-volt dc power system. Laboratory tests with a 28-volt incandescent lamp showed that heat dissipation would not be a problem in the vacuum environment but that a filament or shock mount would have to be developed to withstand vibration. An incandescent quartz lamp was studied because of its small size and high concentration of light.
The first working model of the crew couch was demonstrated during an inspection of CM mockups at North American. As a result, the contractor began redesigning the couch to make it lighter and simpler to adjust. Design investigation was continuing on crew restraint systems in light of the couch changes. An analysis of acceleration forces imposed on crew members during reentry at various couch back and CM angles of attack was nearing completion.
The first evaluation of crew mobility in the International Latex Corporation (ILC) pressure suit was conducted at North American to identify interface problems. Three test subjects performed simulated flight tasks inside a CM mockup. CM spatial restrictions on mobility were shown. Problems involving suit sizes, crew couch dimensions, and restraint harness attachment, adjustment, and release were appraised. Numerous items that conflicted with Apollo systems were noted and passed along to ILC for correction in the continuing suit development program.
North American analyzed lighting conditions in the CM and found that glossy or light-colored garments and pressure suits produced unsatisfactory reflections on glass surfaces. A series of tests were planned to define the allowable limits of reflection on windows and display panel faces to preclude interference with crew performance.
MSC reported that stowage of crew equipment, some of which would be used in both the CM and the LEM, had been worked out. Two portable life support systems and three pressure suits and thermal garments were to be stowed in the CM. Smaller equipment and consumables would be distributed between modules according to mission phase requirements.
To provide a more physiologically acceptable load factor orientation during reentry and abort, MSC was considering revised angles for the crew couch in the CM. To reduce the couch's complexity, North American had proposed adjustments which included removable calf pads and a movable head pad.
At a North American design review, NASA representatives expressed a preference for a fixed CM crew couch. This would have the advantages of simplified design, elimination of couch adjustments by the crew, and better placement of the astronauts to withstand reentry loads. NASA authorized North American to adopt the concept following a three-week study by the company to determine whether a favorable center of gravity could be achieved without a movable couch.
Use of the fixed couch required relocation of the main and side display panels and repositioning of the translational and rotational hand controllers. During rendezvous and docking operations, the crew would still have to adjust their normal body position for proper viewing.
North American demonstrated problems with side-arm controller location and armrest design inside the CM. Major difficulties were found when the subject tried to manipulate controls while wearing a pressurized suit. North American had scheduled further study of these design problems.
North American reported that it had tried several types of restraint systems for the sleeping area in the equipment bay area of the CM. A "net" arrangement worked fairly well and was adaptable to the constant wear garment worn by the crew. However, North American believed that a simpler restraint system was needed, and was pursuing several other concepts.
MSC Crew Systems Division conducted mobility tests of the Apollo prototype space suit inside a mockup of the CM. Technicians also tested the suit on a treadmill. The subjects' carbon dioxide buildup did not exceed two percent; their metabolic rates were about 897,000 joules (850 BTU) per hour at vent pressure, 1,688,000 joules at 2.4 newtons per square centimeter (1,600 BTU at 3.5 psi), and 2,320,000 joules at 3.5 newtons per square centimeter (2,200 BTU at 5.0 psi).
MSC ordered North American to make provisions in the CM to permit charging the 28-volt portable life support system battery from the spacecraft battery charger.
On the following day, the Center informed North American also that a new mechanical clock timer system would be provided in the CM for indicating elapsed time from liftoff and predicting time to and duration of various events during the mission.
The space suit umbilical disconnects were being redesigned to the "buddy concept" and for interchangeability between the CM and the LEM. MSC was reviewing methods for a crewman to return to the LEM following space suit failure on the lunar surface.
ASPO revised the normal and emergency impact limits (20 and 40 g, respectively) to be used as human tolerance criteria for spacecraft design. [These limits superseded those established in the August 14, 1963, North American contract and subsequent correspondence.]
North American conducted an eight-day trial of the prototype Apollo diet. Three test subjects, who continued their normal activities rather than being confined, were given performance and oxygen consumption tests and lean body mass and body compartment water evaluations. The results showed insignificant changes in weight and physiology.
MSC directed North American to assign bioinstrumentation channels to the CM for early manned flights for monitoring the crew's pulse rate, blood pressure, respiration, and temperature. These readings could be obtained simultaneously on any one crew member and by switching from man to man for monitoring the entire crew.
ASPO and the Astronaut Office agreed to provide the crew with food that could be eaten in a liquid or semi-liquid form during emergency pressurized operation. This would permit considerable reduction in the diameter of the emergency feeding port in the helmet visor.
A design review of crew systems checkout for the CM waste management system was held at North American. As a result, MSC established specific requirements for leakage flow measurement and for checkout at North American and Cape Kennedy. The current capability of the checkout unit restricted it to measuring only gross leakage of segments of the system.
Further analysis of the management system was necessary to determine changes needed in the checkout unit.
George E. Mueller, NASA Associate Administrator for Manned Space Flight, summarized recent studies of the dangers of meteoroids and radiation in the Apollo program. Data from the Explorer XVI satellite and ground observations indicated that meteoroids would not be a major hazard. Clouds of protons ejected by solar flares would present a risk to astronauts, but studies of the largest solar flares recorded since 1959 showed that maximum radiation dosages in the CM and the Apollo space suit would have been far below acceptable limits (set in July 1962 by the Space Science Board of the National Academy of Sciences). Cosmic rays would not be a hazard because of their rarity. Radiation in the Van Allen belts was not dangerous because the spacecraft would fly through the belts at high speeds.
MSC directed North American to halt development of a portable light assembly for the CM. It was not required, the Center said, because the spaceship's primary lighting system included extendable floodlights. Small lights on the fingertips of the space suit and a flashlight in the survival kit were also available if needed.
After investigating the maximum radiation levels that were anticipated during Apollo earth orbit missions, North American confirmed the need for some type of nuclear particle detection system (NPDS). Except for periods of extremely high flux rates, the current design of the NPDS was considered adequate. During the same reporting period, North American awarded a contract to Philco to build the system.
MSC's Assistant Director for Flight Crew Operations, Donald K. Slayton, told the Apollo Program Manager that the current display and keyboard (DSKY) for the Block II CSM and for the LEM were not compatible with existing display panel design of both vehicles from the standpoint of lighting, nomenclature presentation, and caution warning philosophy. In his memorandum, Slayton pointed out mandatory operational requirements of the DSKY to ensure compatibility and consistency with the existing spacecraft display panel design.
With reference to lighting, he said all numerics should be green, nomenclature and status lights white, and caution lights should be aviation yellow. All panel lighting should be dimmable throughout the entire range of brightness, including off.
In regard to nomenclature, Slayton pointed out that abbreviations on the DSKY should conform to the North American Interface Control Document (ICD). The referenced ICD was being reviewed by Grumman and North American and was scheduled to be signed December 1, 1964.
Referring to the caution and warning system, he pointed out that all caution lights on the DSKY should be gated into the primary navigation and guidance system (PNGS) caution light on the main instrument panel of both vehicles and into the PNGS caution light on the lower equipment bay panel of the CM.
Slayton requested that preliminary designs of the DSKY panel be submitted to the Subsystem Managers for Controls and Displays for review and approval.
MSC determined that the lights on the fingertips of the space suits were adequate to supplement the CM's interior lighting. Thus North American's efforts to develop a portable light in the spacecraft were canceled. The exact requirements for those fingertip lights now had to be defined. The astronauts preferred red bulbs, which would necessitate a redesign of the existing Gemini system. [See October 29-November 5.]
MSC and North American conducted Part 2 of the mockup review of the CM's forward compartment and lower equipment bay. (Part 1 was accomplished January 14-15. This staged procedure was in line with the contractor's proposal for a progressive review program leading up to the Critical Design Review scheduled for July 19-23.) Except for minor changes, the design was acceptable.
A list of materials that North American reported using in the CM's habitable area omitted more than 70 items that had appeared in earlier such reports. MSC ordered the company to determine why. This item could affect the course of backup toxicity testing. Materials listed as "used but not tested" were given highest priority in toxicity testing.
To ensure compatibility with the spacecraft, MSC specified weight and storage details for the extravehicular visors. The devices, two of which would be carried on each mission and transferred from the CM to the LEM, would afford impact, thermal, and ultraviolet protection for the crew during operations in space or on the lunar surface.
NASA Headquarters had directed that crew water intake be recorded on all Apollo flights. To meet this requirement the Government-furnished water gun would have to be modified to include a metering capability. A gun with this capability was successfully flown on the Gemini VI and Gemini VII flights and could be used without change in the CM and LEM if it could withstand the higher water pressure. Incorporation of the gun could require bracket changes in the CM and the LEM.
MSC awarded $70,000 contract to Rodana Research Corp. to develop emergency medical kits that would "satisfy all inflight and training requirements for the Apollo Command Module and the Lunar Excursion Module." Under terms of contract, two training units would be delivered for each flight, in addition to one mockup and six prototype models. The small kits would contain loaded injectors, tablets, capsules, ointments, inhalers, adhesives, and compressed dressings.
MSC requested LaRC to study the visibility of the S-IVB/SLA combination from the left-hand couch in the command module with the couch in the docked position. (Two positions could be attained, one of them a docking and rendezvous position that moved the seat into a better viewing area from the left-hand window.) LM and CM mockups were already at Langley from the CM-active moving-base docking simulation conducted May-July 1965.
The request was initiated because the flight crew had to rely on an out- the-window reference of the S-IVB/SLA to verify separation of the LM/CSM combination from the S-IVB/SLA. The question arose as to whether the out-the-window reference was sufficient or whether an electromechanical device with a panel readout in the CM was required to verify separation.
Maxime A. Faget, MSC, informed Center Director Robert R. Gilruth there was a continuing effort on lightweight, energy-absorbing, and stowable net couches, and development had been redirected to a nonelastic fabric net couch system attached to existing Apollo attenuation struts. North American Aviation had previously been given the task of investigating the use of net couches on Apollo. Results of that investigation indicated the spacecraft attenuation-strut-vehicle attachments would be overloaded when using net couches. The North American Aviation investigators made their calculations by assuming no-man attenuation in the lateral and longitudinal force directions. Those calculations were recomputed using the design criteria and proper loadings and the results indicated no overloading when using net couches. MSC's Advanced Spacecraft Technology Division had reviewed and approved the efforts, permitting use of the net couches on Apollo and Apollo Applications missions.
Langley Research Center reported on its November study of visibility from the CSM during extraction of the LM from the S-IVB stage. The study had been made in support of the AS-207/208A mission, with assistance of MSC and North American Aviation personnel, to
Charles A. Berry, MSC Director of Medical Research and Operations, proposed establishment of an MSC management program for control of hazardous spacecraft materials, to provide confidence for upcoming long- duration Apollo missions while simultaneously saving overall costs. Berry pointed out that no unified program for control of potentially toxic or flammable spacecraft materials existed and, in the past, individual Program Offices had established their own acceptance criteria for toxological safety and fire hazards.
A senior design review group was established to review the command module stowed equipment and the stowage provisions, to ensure the timely resolution and implementation of changes necessary because of new materials criteria and guidelines. Robert R. Gilruth, MSC Director, would head the group.
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."
In spite of efforts to eliminate all flammable materials from the interior of the spacecraft cabin during flight, it was apparent that this could not be completely accomplished. For example, silicone rubber hoses, flight logs, food, tissues, and other materials would be exposed with in the cabin during portions of the mission. However, flammable materials would be outside their containers only when actually needed. Special fire extinguishers would be carried during flight.
MSC Engineering and Development Director Maxime Faget reported to George Low that his directorate had investigated numerous radiation detectors, ionization particle detectors, and chemical reactive detectors. The directorate had also obtained information from outside sources such as the National Bureau of Standards, Mine Safety Appliances, Parmalee Plastics, Wright-Patterson Air Force Base, and the Air Force Manned Orbiting Laboratory organization. None of the methods investigated could meet the stated requirements for a spacecraft fire detection system.
During integrated testing of the Apollo spacecraft, a well-qualified test pilot accidentally threw two guarded switches marked "CM/SM Separation" instead of the intended adjacent switches marked "CSM/LM Final Sep" to separate the lunar module from the command and service modules. Had the error occurred in a lunar flight, the CM would have separated from the SM, with a high probability of leaving the crew stranded in lunar orbit. Studies of methods to preclude such an accident in actual flight led later to provisions for visual differences in switch covers.
ASPO requested a plan for flight crew tests of sleeping pills and other drugs. The plan was to include number of tests to be performed by each crew member; time of the test with respect to the last sleep period; amount and kind of food and drink taken during a specified time before the test; general physical activity by the crew before taking a drug; and, for comparison purpose, any available statistical information on the effect of these pills after being taken.
MSC asked North American Rockwell to propose a design modification in the CM to add a cold storage compartment for fresh and frozen foods. If the frozen food study appeared promising, then the addition of a small oven or heater, similar in concept to that used by the Air Force on long flights, would also be required.