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CURRENT COLLECTION OF APOLLO COMMAND SERVICE MODULE LUNAR PROGRAM SPACEFLIGHT ARTIFACTS
VIEW	ITEM TYPE	FLOWN STATUS	DESCRIPTION
Overhead View of Apollo Fuel Cell Group Transport Cover Installed Fuel Cell Simulator Obverse View (1) View of Fuel Cell Stack - Up through Base Overhead View Label Plate Label Plate Electrical and LOX/LOH Connectors	APOLLO COMMAND SERVICE MODULE FUEL CELLS	UNFLOWN	APOLLO COMMAND SERVICE MODULE FUEL CELL POWERPLANT GROUP A group of Apollo Command Service Module Fuel Cell Assemblies manufactured by Pratt & Whitney Aircraft Corp under subcontract for North American Aviation (NAA) arrayed as they would have been installed onboard an Apollo Spacecraft. 3 of these cells were employed to generate primary power and and potable water for the Command Module. This sub-collection of Fuel Cell, is comprised of operational (production representaive units) delivered for the Apollo Command Service module and one Simulator (identified as Serial Number 1 on its label plate), which has been modified to support ground simulation testing; outside the addition of the simulator interface, it is identical to production models employed on the CSM. Each of the assemblies measures 44 inches high, 22 inches in diameter, and weighs 245 pounds; and were designed for installation in Sector (Bay) 4 of the SM. Primarily constructed of titanium, stainless steel, and nickel, the Fuel Cells are rated at 27 to 31 volts under normal loads. There are 31 separate cells in a stack, each producing 1 volt, with potassium hydroxide and water as electrolyte. Each cell consists of a hydrogen and an oxygen electrode, a hydrogen and an oxygen gas compartment and the electrolyte. Each gas reacts independently to produce a flow of electrons. The fuel cells are nonregenerative. They are normally operated at 400 degrees F with limits of 385 and 500 degrees. Water-glycol is used for temperature control. The fuel cells use hydrogen, oxygen, and nitrogen under regulated pressure to produce power and, as a by-product, water. Detailed discussion of functionality is addressed in the following paragraphs. The Bacon-type fuel cell powerplant, was configured in a cluster of 3 systems to comprise the CSM power plant; each cell individually coupled to a heat rejection (radiator) system, the hydrogen and oxygen cryogenic storage systems, a water storage system, and a power distribution system. The powerplants generate dc power on demand through an exothermic chemical reaction. A byproduct of this chemical reaction is water, which is fed to a potable water storage tank in the Command Module (CM) where it is used for astronaut consumption and for cooling purposes in the environmental control subsystem. The amount of water produced is proportional to the ampere-hours. . Apollo Fuel Cell Power Plants installed in Command Service Module Bay Sector 4 The water separation, reactant control, and heat transfer components are mounted in a compact accessory section attached directly above the pressure jacket. Powerplant temperature is controlled by the primary (hydrogen) and secondary (glycol) loops. The hydrogen pump, providing continuous circulation of hydrogen in the primary loop, withdraws water vapor and heat from the stack of cells. The primary bypass valve regulates flow through the hydrogen regenerator to impart exhaust heat to the incoming hydrogen gas as required to maintain the proper cell temperature. The exhaust gas flows to the condenser where waste heat is transferred to the glycol, the resultant temperature decrease liquifying some of the water vapor. The motor-driven centrifugal water separator extracts the liquid and feeds it to the potable water tank in the CM. The temperature of the hydrogen-water vapor exiting from the condenser is controlled by a bypass valve which regulates flow through a secondary regenerator to a control condenser exhaust within desired limits. The cool gas is then pumped back to the fuel cell through the primary regenerator by a motor-driven vane pump, which also compensates for pressure losses due to water extraction and cooling. Waste heat, transferred to the glycol in the condenser, is transported to the radiators located on the fairing between, the CM and SM, where it is radiated into space. Radiator area is sized to reject the waste heat resulting from operation in the normal power range. If an emergency arises in which an extremely low power level is required, individual controls can bypass three of the eight radiator panels for each powerplant. This area reduction improves the margin for radiator freezing which could result from the lack of sufficient waste heat to maintain adequate glycol temperature. This is not a normal procedure and is considered irreversible due to freezing of the bypassed panels. Reactant valves provide the connection between the powerplants and the cryogenic system. They are opened during pre-launch fuel cell startup and closed only after a powerplant malfunction necessitating its isolation from the cryogenic system. Before launch, a valve switch is operated to apply a holding voltage to the open solenoid of the hydrogen and oxygen reactant valves of the three powerplants. This voltage is required only during boost to prevent inadvertent closure due to the effects of high vibration. The reactant valves cannot be closed with this holding voltage applied. After earth orbit insertion, the holding voltage is removed and three circuit breakers are opened to prevent valve closure through inadvertent activation of the reactant valve switches. Nitrogen is stored in each powerplant at 1500 psia and regulated to a pressure of 53 psia. Output of the regulator pressurizes the electrolyte in each cell through a diaphragm arrangement, the coolant loop through an accumulator, and is coupled to the oxygen and hydrogen regulators as a reference pressure. Cryogenic oxygen, supplied to the powerplants at 900 +/- 35 psia, absorbs heat in the lines, absorbs additional heat in the fuel cell powerplant reactant preheater, and reaches the oxygen regulator in a gaseous form at temperatures above 0 degrees F. The differential oxygen regulator reduces pressure to 9.5 psia above the nitrogen reference, thus supplying it to the fuel cell stack at 62.5 psia. Within the porous oxygen electrodes, the oxygen reacts with the water in the electrolyte and the electrons provided by the external circuit to produce hydroxyl ions. Cryogenic hydrogen, supplied to the powerplants at 245 (+15, -20) psia, is heated in the same manner as the oxygen. The differential hydrogen regulator deduces the pressure to 8.5 psia above the reference nitrogen, thus supplying it in a gaseous form to the fuel cells at 61.5 psia. The hydrogen reacts in the porous hydrogen electrodes with the hydroxyl ions in the electrolyte to produce electrons, water vapor, and heat. The nickel electrodes act as a catalyst in the reaction. The water vapor and heat are withdrawn by the circulation of hydrogen gas in the primary loop and the electrons are supplied to the load. Each of the 31 cells contains electrolyte which on initial fill consists of approximately 83 percent potassium hydroxide (KOH) and 17 percent water by weight. The powerplant is initially conditioned to increase the water ratio, and during normal operation, water content will vary between 23 and 28 percent. At this ratio, the electrolyte has a critical temperature of 360 degrees F. Powerplant electrochemical reaction becomes effective at the critical temperature. The powerplants are heated above the critical temperature by ground support equipment. A load on the powerplant of approximately 563 watts is required to maintain it above the normal minimum operating temperature of 385§F. The automatic in-line heater circuit will maintain powerplant temperature in this range with smaller loads applied.
Rear Assembly Close View (1) Lateral View Lateral View	APOLLO COMMAND MODULE OXYGEN CONTROL PANEL	UNFLOWN	APOLLO COMMAND MODULE (BLOCK I) OXYGEN CONTROL PANEL ASSEMBLY Apollo Command Module (CM) Oxygen Control Panel (identified as panel 314 in the APOLLO OPERATIONS HANDBOOK for spacecraft 012), manufactured circa 1967/1968 (derived from date stamps on artifact) which comprise part of the Environmental Control system. This panel, as a component of the oxygen subsystem, controls the flow of oxygen within the CM, provides access to a reserve supply for use during entry and emergencies, regulates the pressure of oxygen supplied to subsystem and pressure suit circuit components, controls cabin pressure, controls pressure in water tanks and the glycol reservoir, and provides for purging the pressure suit circuit. Significant differences between the BLOCK I O2 Control panel in this collection and BLOCK 2 variant include relocation of the Regulator Valve assembly from the primary panel (Block one O2 regulator was onboard the primary panel, and shifted to a separate subpanel for the Block II spacecraft) and the provisioning of a Portable Life Support System (PLSS) port (Block II 02 panel had no PLSS port). Inspection Stamps
Operator Interface Lateral View/NAA Label Plate Rear View CSM (Block I) Panel 201	APOLLO COMMAND MODULE WASTE DISPOSAL SELECTOR VALVE	UNFLOWN	APOLLO COMMAND MODULE (BLOCK I) WASTE DISPOSAL SELECTOR VALVE An Apollo Command Service Module (Block I) Waste Disposal Selector Valve assembly manufactured circa 1965 under Nasa Apollo Contract NAS9-150 by Accessory Products Company (APCO). Part of the Environmental Control System (ECS) Waste Management System / Waste Management-Selector, this valve was used to route human (liquid and solid) bio-waste products originating from a Fecal Canister, Urine Receptacle, Urine Volume Sampling Measuring Systems Unit (UVSMS) and Vacumn Cleaner assembly to overboard discharge. The Waste Management System (including this Valve) was redesigned for the Block II CSM. Diagram at left shows location of valve assembly handle on Panel 201 of the Block I CSM.
Lateral View Inlet/Outlet Ports Tag Data	APOLLO COMMAND MODULE ENVIRONMENTAL CONTROL	UNDETERMINED	APOLLO COMMAND MODULE (BLOCK II) PRIMARY WATER-GLYCOL COOLANT PUMP Apollo Command Module primary water-glycol coolant pump manufactured in 1969 by Airesearch under subcontract to North American Aviation / Rockwell (CSM integrator under NASA contract NAS9-150 ). Two of these centrifugal pumps (primary/backup) were installed as part of the Environmental Control System to circulate 200 lb/hr of water/ethylene glycol coolant through the heat absorption and rejection equipment in the CSM. Typically throughout the course of a mission, only one pump would be utilized (in continous mode) with the secondary pump being reserved in the event of primary unit/cooling loop failure.
Valve Assembly Lateral View 1 Lateral View 2 Tag Data CSM BLOCK II PANEL 303	APOLLO COMMAND MODULE PRIMARY TEMP CONTROL ASSEMBLY	UNDETERMINED	APOLLO COMMAND MODULE (BLOCK II) PRIMARY TEMPERATURE CONTROL A Block II Apollo Command Service Module Environmental Control System (ECS) Primary Cabin Temperature Flow Control Valve and Manual Crew Selector Knob assembly manufactured circa 1968 by AIRESEARCH under CSM contract NAS 9-150. This assembly regulated the primary glycol loop in the Apollo Command Module and was normally positioned automatically by the cabin temperature control or manually by means of an override control on the face of the valve. The valve was located on the CSM panel 303 (a diagram of the panel is viewable to the left of this narrative) The motor-operated valve is manually controlled by the back-up mode control knob. Rotational movement from H to C is approximately ½ turn with the dual valve on a single shaft permitting water-glycol flow to route to the heat exchanger. Rotation toward H (heat) position results in proportional increase in cabin temperature by directing warm water-glycol to the cabin heat-exchanger. Rotation towards C (cool) position results in proportional decrease in cabin temperature by directing cool water-glycol to the cabin heat exchanger.
Matched Ground and Service Module Oxygen Vent Line Couplers Mated Ground and Service Module Oxygen Vent Couplers Service Module Oxygen Fill Coupler Data Tag Ground Hydrogen Vent Coupler Stamped Data	APOLLO SERVICE MODULE FUEL CELL CRYOGENIC SUB-SYSTEM	UNFLOWN	APOLLO SERVICE MODULE CRYOGENIC HYDROGEN AND OXYGEN COUPLERS This sub-collection is comprised of Cryogenic couplers installed onboard the Service Module and affilated ground umbilicles which supplied liquid Oxygen and Hydrogen to the Apollo Fuel Cell storage tanks. The Service Module coupling devices were manufactured by Beech Aircraft; the ground couplers were subcontracted by North American Aviation to Stratos-Western (Fairchild Hiller Corporation) under NASA Contract NAS9-150. Cryogenic Hydrogen and Oxygen comprised the constituant reactants used by the (3) onboard Bacon Fuel cells to provide power, drinking water and heating (an example of a fuel cell is also documented within this collection in a preceeding entry). The Oxygen tanks also supplied metabolic breathing oxygen to the crew Cryogenic Fill and Vent Port Locations
O2 Regulator Assembly Top View O2 Regulator Assembly Bottom View	APOLLO COMMAND MODULE OXYGEN REGULATOR ASSEMBLY	Unflown	APOLLO COMMAND MODULE OXYGEN REGULATOR An Apollo Command Module Oxygen (O2) Redundant Main Regulator; date of production assessed as 1973 which likely affiliates this component as a flight ready spare for the Apollo-Skylab Command Modules - Spacecrafts AS116 through AS118 or the ATSP/Skylab Rescue vehicle (AS119). The main regulator reduces the O2 supply pressure to 100 + 10 psig for use by subsystem components. The regulator assembly is a dual unit which is normally operated in parallel. Selector valves at the inlet to the assembly provide a means of isolating either of the units in case of failure, or for shutting them both off. Integral relief valves limit the downstream pressure to 140 psig maximum. APOLLO 14 Oxygen Control Panel - switch tabs (toggled to the up or "OPEN" position) for Oxygen Regulator Assembly can be seen immediately to left of "Oxygen Control Panel" label* (image courtesy of Ray Holt)
AEROJET Tag Assembly Lateral View Assembly Detail View Apollo SPS Main Engine Functional Flow Diagram	APOLLO SERVICE PROPULSION SYSTEM BIPROPELLANT VALVE SUBSYSTEM	Likely Flight Ready Spare (Unflown)	APOLLO SERVICE PROPULSION SYSTEM PNEUMATIC CONTROL ASSEMBLY An Apollo Service Propulsion System (SPS) Primary Bipropellant Valve Pneumatic Control Assembly used to regulate the introduction of fuel and oxidizer into the Command Service Modules main engine. Manufactured by General Tire's AEROJET Liquid Rocket Operations Division (NASA Prime Contractor for the Apollo program Service Module propulsion system). Both a primary and secondary assembly were installed ontop the Apollo SPS thrust chamber; each assembly consisting of one each nitrogen pressure vessel, injector prevalve, nitrogen regulator, nitrogen relief valve, two solenoid control valve, and two actuators. Determination that this is the primary assembly is based on Regulator labeling (tag carries the "A" designation) and the 2 Solenoid Control valves which carry the "-1" and the "-2" designation respectively stamped on the exterior of each valve. A functional diagram of the SPS MAIN ENGINE depicting the relationship of the Bipropellant valve assembly may be viewed by clicking here or on the image to the lower left; a detailed description of this assembly follows below. Nitrogen tanks are mounted on the bipropellant valve assembly to supply pressure to the injector prevalves. One tank is in the primary pneumatic control system (A) and the other tank is in the secondary pneumatic control system (B). The tanks each contain 5.8 cubic inches of nitrogenÄ enough to operate the valves 43 times with an initial nominal pressure of 2500 psi. The injector prevalves are two-position, solenoid operated valves, one for each pneumatic control system, and identified as A and B. The valve is energized open and spring-loaded closed. The prevalves, when energized open, allow nitrogen supply tank pressure to be directed through the regulator into a relief valve and to a pair of solenoid control valves. The single-stage regulator is installed in each pneumatic control system between the injector prevalves and the solenoid control valves. The regulator reduces the nitrogen pressure to 190-230 psi. The pressure relief valve is located downstream from the regulator to limit the pressure applied to the solenoid control valves in case a regulator malfunctions. The orifice between the injector prevalve and regulator restricts the flow of nitrogen and allows the relief valve to relieve the pressure overboard in the event the regulator malfunctions, preventing damage to the solenoid control valves and actuators. Four solenoid-operated, three-way, two-position control valves (from both the primary and secondary systems) are used for actuator control. Two solenoid control valves are located in each pneumatic control system. The solenoid control valves in the primary system are identified as l and 2 and the two in the secondary system are identified as 3 and 4. The solenoid control valves in the primary system control actuator and ball valves 1 and 2. The two solenoid control valves in the secondary system control actuator and ball valves 3 and 4. Four piston-type, pneumatically operated actuators control the eight propellant ball valves. Each actuator piston is mechanically connected to a pair of propellant ball valves, one fuel and one oxidizer. When the solenoid control valves are opened, pneumatic pressure is applied to the opening side of the actuators. The spring pressure on the closing side is overcome and the actuator piston moves. Utilizing a rack and pinion gear, linear motion of the actuator connecting arm is converted into rotary motion, which opens the propellant ball valves. When the engine firing signal is removed from the solenoid control valves, the solenoid control valves close, removing the pneumatic pressure source from the opening side of the actuators. The actuator spring pressure then forces the actuator piston to move in the opposite direction, causing the propellant ball valves to close. The piston movement forces the remaining nitrogen on the opening side of the actuator back through the solenoid control valves where it is vented overboard. Each actuator contains a pair of linear position transducers. One supplies information on the position of the ball valve to the main display console and the other information to telemetry.The eight propellant ball valves are used to distribute fuel and oxidizer to the engine injector assembly.
Top View Label Plate Lateral View - O2 Relief Assembly Base View System Tank Valve Module Component Diagram	APOLLO OXYGEN/HYDROGEN SERVICE MODULE	Flight Ready Spare (Unflown)	APOLLO OXYGEN/HYDROGEN SERVICE MODULE A System (Tank) Valve Module (Apollo Oxygen Hydrogen Service Module) manufactured by PARKER-HANNIFIN circa 1967-1971 used to provide overboard relief of elevated pressures within the stored LH2 (Liquid Hydrogen) and LO2 (Liquid Oxygen) tanks in the Apollo Command Service Module (CSM). This system also sensed LH2/LO2 tank pressures, regulated the tank heaters and controlled the tank destratification motors (motors used to execute the CRYO-STIR in the LOX/LH2 tanks for "slush" mitigation). The modules were in-line between the LH2/LO2 cryogenic tanks and the CSM Fuel Cells. The Systems (Tank) Valve Modules for the hydrogen and oxygen systems are functionally identical. Each module contrains two relief valves, two pressure transducers, two pressure switches and one check valve. The relief valves are a differential type designed to be unaffected by back pressure in the downstream plumbing, The valve has temperature compensation and a self-aligning valve seat. Relief crack pressure is 273 psig minimum for hydrogen tanks and 983 psig minimum for oxygen tanks. Full flow pressures (LO2) is 1010 psig (maximum) and for LH2 285 psig (maximum). Module pressure switches are a double pole single throw absolute device. A positive reference pressure (less then atmospheric) is used to trim the mechanical trip mechanism to obtain the absolute switch actuation settings. Reference pressure is typically between 4 to 10 psia. The motor driven switch controls power to both the tank heaters and destratification motors. The pressure transducers, are an absolute (vacuum reference) device. Each transducer consists of a silicon pickup comprised of four sensors mounted on a damped edge diaphragm and an integral signal conditioner. The unit senses tank pressure through the discharge line from the tank; signal conditioner output is 0-5 VDC analog output which is linearly proportioned to tank pressure. The check valve, is designed to open at a differential pressure of approximately 1 psia. The single poppet is spring loaded and has a large area to prevent chattering during flow in the normal direction. This large area also helps in obtaining a positive seal if pressurized in the reverse direction.
RCS Helium Check Valve (Obverse)	APOLLO CM/SM HELIUM CHECK VALVE	Unflown	APOLLO CM/SM RCS CHECK VALVE A Reaction Control System (RCS) Helium Check Valve assembly manufactured by Accessory Products Corporation (APCO) for the Apollo Command Module and Service Module (Service Propulsion System) Reaction Control System (RCS) Propellant Pressurization Section under NASA contract NAS9-150. Produced circa 1964, two check valve assemblies, one for oxidizer and one for fuel, permit helium flow to the tanks and prevent propellant or propellant vapor flow into the presurization system if seepage or failure occurs in the propellant tank bladders.
He Regulator(Obverse) He Regulator(Top) Valve Schematic Service Module RCS System Diagram	APOLLO SPS HELIUM REGULATOR	Unflown	APOLLO SERVICE MODULE RCS HELIUM REGULATOR Reaction Control System (RCS) Helium Pressure Regulator assembly manufactured by Fairchild Stratos Corp (Western Division) for the Apollo Service Module (Service Propulsion System), Reaction Control System pressurization system under NASA contract NAS9-150 for North American Aviation (NAA). The dual, series configured regulators (produced 1965) received gas from the SPS helium tank isolation valve and reduced ambient tank pressure of 4150 PSIA to approx 220 PSIA (nominal) before forwarding to the downstream RCS check valve (see RCS Check Valve description which precedes this entry). Each assembly incorporates two (primary and secondary) regulators connected in series. If the primary regulator fails open, the secondary regulator will maintain slightly higher but acceptable pressures. Diagram to the left depicts functional relationship/location of regulator in the RCS system
He Relief Valve Label Data	APOLLO SERVICE PROPULSION SYSTEM HE RELIEF VALVE	Unflown	APOLLO SERVICE PROPULSION SYSTEM HELIUM RELIEF VALVE Helium Pressure Relief Valve manufactured by CALMEC Manufacturing Corp for the Apollo Service Propulsion System (SPS) pressurization subsystem under subcontract to NAA (NASA contract NAS9-150). The pressure relief valve (one of two which would have been integrated into the SPS) consists of a relief valve, a diaphragm, and a filter. In the event that excessive helium or propellant vapor ruptured the diaphragm, the relief valve opened and vented the system. The relief valve would close and reseal after the excessive pressure had returned to the operating level. The diaphragm provided a more positive seal of helium than a relief valve. The filter prevents any fragments from the diaphragm from entering onto the relief valve seat. The relief valve opens at a pressure of 212 psi after the diaphragm ruptures at about 213 psi. The valve will close when pressure drops to 208 psi. Regulated helium was utilized by the SPS to provide positive pressure to the fuel and oxidizer storage tanks and drive the propellant fluids into the Apollo Command Service Module's main engine.
Complete view Side view Detailed view of QA Stamps	Apollo Ablative Heatshield Block	Not Flown	APOLLO COMMAND SERVICE MODULE AVCOAT 5026 HEAT SHIELD BLOCK A complete AVCOAT 5026-39HCG HeatShield block (1 square foot/12x12inch; 2 inch thick) manufactured in 1966 as a component of the Command Service Module (CSM) Thermal Protection System. Developed by AVCO corporation, with integration by NAA (North American Aviation), the block is comprised of an extremely lightweight fiberglass honeycomb which is handfilled by airgun with the ablative resin material. This specimen has 1,024 individual handfilled cells, the completed CSM heatshield had 400,000 cells. After manufacturing, each block is cut to size in small sheets, fitted snugly on the CSM, and vacuum bonded firmly to the primary heat shield. The ablative charactoristic (i.e. the material essentially melts and chars away during re-entry) mitigates the 20,000 degree heat experienced by the CSM as it transits through the extreme thermo-dynamic phase of the re-entry cooridor. Images at the left show the cellular construct of the heat block. An excellent discussion and graphics of Apollo heatshield properties as well as a description of the process for building/integrating the AVCO material onto the CSM can be found at Phil Parkers Website

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