NAA engineers began preliminary layouts to define the elements of the command module (CM) configuration. Additional requirements and limitations imposed on the CM included reduction in diameter, paraglider compatibility, 250 pounds of radiation protection water, redundant propellant tankage for the attitude control system, and an increase in system weight and volume.

Layouts were also being prepared to identify equipment requirements in the CM aft compartment, while layouts depicting the position and orientation of the three crewmen during various phases of the lunar flight were complete.

Basic load paths for the CM inner structure, an access door through the outer structure, and the three side wall hatches for crew entrance and exit had been tentatively defined. The CM inner structure was currently of bonded aluminum honeycomb, the outer structure of high-temperature, brazed steel honeycomb.

NAA decided to retain the inward-opening pull-down concept for the spacecraft crew hatch, which would use plain through bolts for lower sill attachment and a manual jack-screw device to supply the force necessary to seat and unseat the hatch.

Concurrently, a number of NAA latching concepts were in preparation for presentation to NASA, including that of an outward-opening, quick- opening crew door without an outer emergency panel. This design, however, had weight and complexity disadvantages, as well as requiring explosive charges.

NAA's evaluation of the emergency blow-out hatch study showed that the linear-shaped explosive charge should be installed on the outside of the command module, with a backup structure and an epoxy-foam-filled annulus on the inside of the module to trap fragmentation and gases. Detail drawings of the crew hatch were prepared for fabrication of actual test sections.

The establishment of a basic command module (CM) airlock and docking design criteria were discussed by NAA and NASA representatives. While NASA preferred a closed-hatch, one-man airlock system, NAA had based its design on an open-hatch, two-man airlock operation.

Another closed-hatch configuration under consideration would entirely eliminate the CM airlock. Astronauts transferring to and from the lunar excursion module would be in a pressurized environment constantly.

Robert R. Gilruth, Director of MSC, presented details of the Apollo spacecraft at the Institute of the Aerospace Sciences meeting in Seattle, Wash. During launch and reentry, the three-man crew would be seated in adjacent couches; during other phases of flight, the center couch would be stowed to permit more freedom of movement. The Apollo command module cabin would have 365 cubic feet of volume, with 22 cubic feet of free area available to the crew: "The small end of the command module may contain an airlock; when the lunar excursion module is not attached, the airlock would permit a pressure-suited crewman to exit to free space without decompressing the cabin. Crew ingress and egress while on earth will be through a hatch in the side of the command module."

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.

Elimination of the requirement for personal parachutes nullified consideration of a command module (CM) blowout emergency escape hatch. A set of quick-acting latches for the inward-opening crew hatch would be needed, however, to provide a means of egress following a forced landing. The latches would be operable from outside as well as inside the pressure vessel. Outside hardware for securing the ablative panel over the crew door would be required as well as a method of releasing the panel from inside the CM.

North American made a number of changes in the layout of the CM:

• Putting the lithium hydroxide canisters in the lower equipment bay and food stowage compartments in the aft equipment bay.
• Regrouping equipment in the left-hand forward equipment bay to make pressure suit disconnects easier to reach and to permit a more advanced packaging concept for the cabin heat exchanger.
• Moving the waste management control panel and urine and chemical tanks to the right-hand equipment bay.
• Revising the aft compartment control layout to eliminate the landing impact attenuation system and to add tie rods for retaining the heatshield.
• Preparing a design which would incorporate the quick release of the crew hatch with operation of the center window (drawings were released, and target weights and criteria were established).
• Redesigning the crew couch positioning mechanism and folding capabilities.
• Modifying the footrests to prevent the crew's damaging the sextant.

The second prototype space suit was received by MSC's Crew Systems Division. Preliminary tests showed little improvement in mobility over the first suit. On October 24-25, a space suit mobility demonstration was held at North American. The results showed that the suit had less shoulder mobility than the earlier version, but more lower limb mobility. Astronaut John W. Young, wearing the pressurized suit and a mockup portable life support system (PLSS), attempted an egress through the CM hatch but encountered considerable difficulty. At the same time, tests of the suit-couch- restraint system interfaces and control display layout were begun at the Navy's Aviation Medical Acceleration Laboratory centrifuge in Johnsville, Pa. Major problems were restriction of downward vision by the helmet, extension of the suit elbow arm beyond the couch, and awkward reach patterns to the lower part of the control panel. On October 30-November 1, lunar task studies with the suit were carried out at Wright-Patterson Air Force Base in a KC-135 aircraft at simulated lunar gravity. Mobility tests were made with the suit pressurized and a PLSS attached.

North American completed its initial phase of crew transfer tests using a mockup of the CM/LEM transfer tunnel. Subjects wearing pressure suits were suspended and counterbalanced in a special torso harness to simulate weightlessness; hatches and docking mechanisms were supported by counterweight devices. The entire tunnel mockup was mounted on an air-bearing, frictionless table. Preliminary results showed that the crew could remove and install the hatches and docking mechanisms fairly easily.

ASPO decided upon transfer through free space as the backup mode for the crew's getting from the LEM back to the CM if the two spacecraft could not be pressurized. North American had not designed the CM for extravehicular activity nor for passage through the docking tunnel in a pressurized suit. Thus there was no way for the LEM crew to transfer to the CM unless docking was successfully accomplished. ASPO considered crew transfer in a pressurized suit both through the docking tunnel and through space to be a double redundancy that could not be afforded.

After reviewing the requirement for extravehicular transfer (EVT) from the LEM to the CM, MSC reaffirmed its validity. The Center already had approved additional fuel for the CM, to lengthen its rendezvousing range, and modifications of the vehicle's hatch to permit exterior operation. The need for a greater protection for the astronaut during EVT would be determined largely by current thermal tests of the pressure suit being conducted by NASA and Hamilton Standard. While the emergency oxygen system was unnecessary during normal transfer from one vehicle to the other, it was essential during EVT or lunar surface activities.

Officials from North American and the three NASA centers most concerned (MSFC, KSC, and MSC) discussed the environmental umbilical arrangement for the CM. The current configuration hampered rapid crew egress and therefore did not meet emergency requirements. This group put forth several alternative designs, including lengthening the umbilical hood and relocating the door or hatch.

MSC's Assistant Director for Flight Operations, Christopher C. Kraft, Jr., told ASPO Manager Joseph F. Shea that postlanding operational procedures require that recovery force personnel have the capability of gaining access into the interior of the CM through the main crew hatch. This was necessary, he said, so recovery force swimmers could provide immediate aid to the crew, if required, and for normal postlanding operations by recovery engineers such as spacecraft shutdown, crew removal, data retrieval, etc.

Kraft said the crew compartment heatshield might char upon reentry in such a manner as to make it difficult to distinguish the outline of the main egress hatch. This potential problem and the necessity of applying a force outward to free the hatch might demand use of a "crow bar" tool to chip the ablator and apply a prying force on the hatch.

Since this would be a special tool, it would have to be distributed to recovery forces on a worldwide basis or be carried aboard the spacecraft. Kraft requested that the tool be mounted onboard the spacecraft in a manner to be readily accessible. He requested that the design incorporate a method to preclude loss of the tool - either by designing the tool to float or by attaching it to the spacecraft by a lanyard.

A North American layout of the volume swept by the CM couch and crewmen during landing impact attenuation showed several areas where the couch and or crewmen struck the CM structure or stowed equipment. One area of such interference was that the center crewman's helmet could overlap about four inches into the volume occupied by the portable life support system (PLSS) stowed beneath the side access hatch. The PLSS stowage was recently changed to this position at North American's recommendation because the original stowage position on the aft bulkhead interfered with the couch attenuation envelope. The contractor was directed by MSC to explain this situation.

MSC Director of Flight Crew Operations Donald K. Slayton pointed out to ASPO Manager Joseph F. Shea that LM-to-CSM crew rescue was impossible. Slayton said

1. there was no way for the portable life support system and crewman to traverse from the LM front hatch to the CSM side hatch in zero-g docked operations, because there was no restraint system or tether attach points in the vicinity of the CSM hatch to permit the crewman to stabilize himself and work to open the hatch; and
2. there was no way to control the Apollo inner hatch (35-43 kilograms) to ensure that it would not inadvertently damage its seals, the spacecraft wiring, or the pressure bulkhead.

The final report of the Spacecraft and Ground Support Equipment Configuration Panel (No. 1) was accepted by the Apollo 204 Review Board. The panel had been assigned the task of documenting the physical configuration of the spacecraft and ground support equipment immediately before and during the January 27 fire, including equipment, switch position, and nonflight items in the cockpit. The panel was also to document differences from the expected launch configuration and configurations used in previous testing (such as altitude-chamber testing).

During the investigation the panel had discovered a number of items which might have had relevance to flame propagation:

• An engineering order, released at North American Aviation's Downey facility on January 20, provided direction to inspect the polyurethane foam in specified areas and coat the silicone rubber to meet flammability requirements. The direction was not recorded in the configuration verification record as of the start of the Space Vehicle Plugs-Out Integrated Test and was not accomplished on spacecraft 012. This item was considered as possibly significant in terms of fuel for the fire and a medium for flame propagation.
• Polyethylene bags covered the hose fitting for the drinking water dispenser and the battery-instrumentation cable and connectors and transducer, which were placed on the aft bulkhead near the batteries. The bags were made of nonflight materials.
• Two polyurethane pads, covered with Velostat, were stowed over couch struts. The pads were placed in the spacecraft to protect the struts, wiring, and aft bulkhead during the planned emergency egress at the end of the test. These items were of nonflight material and were not documented by quality inspection records.
• Three packages of switching checklists from the Operational Checkout Procedure and one package of system malfunction procedures, in a manila folder, were stowed on the crew couches and on a shelf. These items were on unqualified paper and, while required for the test, they were not documented by quality inspection records.
• Nylon protective sleeves were covering all three crewmen's oxygen umbilicals. These sleeves were nonflight items.
• Three ground-support-equipment window covers had been temporarily installed to protect the windows and were nonflight items in the spacecraft at the time of the accident. Another such cover for the side hatch window was removed by the crew and stowed inside the command module. These covers were of nylon fabric; flight covers were made of aluminized Mylar.
• Velcro pile had been installed to protect the Velcro hood on the command module floor. It would have been removed before the flight.
• "Remove before flight" streamers installed in the command module interior were additional nonflight items.
• Polyethylene zipper tubing, installed to protect hand controller cables, was a nonflight item and was additional material in the command module.

Finding

Eighty engineering orders effective for spacecraft 012 had not been carried out at the time of the accident. Of these, twenty were specified to be completed after the test; four did not affect configuration.

Determination

Test requirements had no defined relationships with the open status of 56 engineering orders. The reason not all work items and engineering orders were closed was late receipt of changes or further work scheduled to be completed before launch.

Finding

Items not documented by quality inspection records had been placed on board the spacecraft during preparation for the Space Vehicle Plugs- Out Integrated Test.

Determination

Procedures for controlling entry of items into the spacecraft were not strictly enforced.

The final report of the Ground Emergency Provisions Panel (Panel 13) accepted by the Apollo 204 Review Board submitted 14 findings and determinations. The panel had been charged with reviewing the adequacy of planned ground procedures for the January 27 spacecraft 012 manned test, as well as determining whether emergency procedures existed for all appropriate activities. The review was to concentrate on activity at the launch site and to include recommendations for changes or new emergency procedures if deemed necessary.

The panel approached its task in two phases. First, it reviewed the emergency provisions at the time of the CM 012 accident, investigating

1. the procedures in published documents,
2. the emergency equipment inside and outside the spacecraft, and
3. the emergency training of the flight crew and checkout test team.

Findings and determinations included:

Finding

The applicable test documents and flight crew procedures for the AS- 204 Space Vehicle Plugs-Out Integrated Test did not include safety considerations, emergency procedures, or emergency equipment requirements relative to the possibility of an internal spacecraft fire during the operation.

Determination

The absence of any significant emergency preplanning indicated that the test configuration (pressurized 100-percent-oxygen cabin atmosphere) was not classified as potentially hazardous.

Finding

The propagation rate of the fire in the accident was extremely rapid. Removal of the three spacecraft hatches, from either the inside or the outside, for emergency exit required a minimum of 40 to 70 seconds, respectively, under ideal conditions.

Determination

Considering the rapid propagation of the fire and the time constraints imposed by the spacecraft hatch configuration, it is doubtful that any amount of emergency preparation would have precluded injury to the crew before egress.

Finding

Procedures for unaided egress from the spacecraft were documented and available. The AS-204 flight crew had participated in a total of eight egress exercises employing those procedures.

Determination

The 204 flight crew was familiar with and well trained in the documented emergency crew procedures for effecting unaided egress.

Finding

The spacecraft pad work team on duty at the time of the accident had not been given emergency training drills for combating fires in or around the spacecraft or for emergency crew egress. They were trained and equipped only for a normal hatch removal operation.

Determination

The spacecraft pad work team was not properly trained or equipped to effect an efficient rescue operation under the conditions resulting from the fire.

Finding

Frequent interruptions and failures had been experienced in the overall communications system during the operations preceding the accident. At the time the accident occurred, the status of the system was still under assessment.

Determination

The status of the overall communications was marginal for the support of a normal operation. It could not be assessed as adequate in the presence of an emergency condition.

Finding

Emergency equipment provided at the spacecraft work levels consisted of portable carbon dioxide fire extinguishers, rocket-propellant-fuel-handler's gas masks, and 4.4-centimeter-diameter fire hoses.

Determination

The existing emergency equipment was not adequate to cope with the conditions of the fire. Suitable breathing apparatus, additional portable carbon dioxide fire extinguishers, direct personnel evacuation routes, and smoke removal ventilation were significant items that would have improved the reaction capability of the personnel.

Finding

Under the existing method of test procedure processing at KSC, the safety offices reviewed only the procedures noted in the operational checkout procedure outline as involving hazards. Official approval by KSC and Air Force Eastern Test Range Safety was given after the procedure was published and released.

Determination

The scope of contractor and KSC Safety Office participation in test procedure development was loosely defined and poorly documented. Post-procedure-release approval by the KSC Safety Office did not ensure positive and timely coordination of all safety considerations.

The Apollo 204 Review Board was scheduled to review the final report of its Historical Data Panel (Panel No. 6). The panel had been assigned to assemble, summarize, and interpret historical data concerning the spacecraft and associated systems pertinent to the January 27 fire. The data were to include such records as the spacecraft log, failure reports, and other quality engineering and inspection documents. In addition the panel prepared narratives to reflect the relationship and flow of significant review and acceptance points and substantiating documentation and presented a brief history of prelaunch operations performed on spacecraft 012 at Kennedy Space Center.

In its final report to the Review Board the Historical Data Panel submitted eight findings and determinations. Among them were:

Finding

The Ingress-Egress Log disclosed several instances where tools and equipment were carried into the spacecraft, but the log did not indicate these items had been removed.

Determination

Maintenance of the Ingress-Egress Log was inadequate.

Finding

Inspection personnel did not perform a prescheduled inspection with a checklist before hatch closing.

Determination

Inspection personnel could not verify specific functions during that period.

Finding

At the time of the spacecraft 012 shipment to KSC, the contractor submitted an incomplete list of open items. A revision of that list significantly and substantially enlarged the list of open items.

Determination

The true status of the spacecraft was not identified by the contractor.

The Apollo 204 Review Board accepted the final report of its Design Review Panel (No.9), whose duty had been to conduct Critical Design Reviews of systems or subsystems that might be potential ignition sources within the Apollo command module cockpit or that might provide a combustible condition in either normal or failed conditions. The panel was also to consider areas such as the glycol plumbing configuration; electrical wiring and its protection, physical and electrical; and such potential ignition sources as motors, relays, and corona discharge. Other areas would include egress augmentation and the basic cabin atmosphere concept (one-gas versus two-gas).

The contemplated spacecraft configuration for the next scheduled manned flight (spacecraft 101, Block II) was significantly different from that of spacecraft 012 (Block I), in which the January 27 fire had occurred. Therefore, both configurations were to be reviewed - the Block I configuration as an aid in determining possible sources for the fire, the Block II to evaluate the system design characteristics and potential design change requirements to prevent recurrence of fire.

The panel's final report to the Review Board contained findings on ignition and flammability, cabin atmosphere, review of egress process, and review of the flight and ground voice communications. Among them were:

Finding

Flammable, nonmetallic materials were used throughout the spacecraft. In the Block I and Block II spacecraft design, combustible materials were contiguous to potential ignition sources.

Determination

In the Block I and Block II spacecraft design, combustible materials were exposed in sufficient quantities to constitute a fire hazard.

Finding

The spacesuit contained power wiring to electronic circuits. The astronauts could be electrically insulated.

Determination

Both the power wiring and potential for static discharge constituted possible ignition sources in the presence of combustible materials. The wiring in the suit could fail from working or bending.

Finding

Residues of RS89 (inhibited ethylene glycol/water solution) after drying were both corrosive and combustible. RS89 was corrosive to wire bundles because of its inhibitor.

Determination

Because of the corrosive and combustible properties of the residues, RS89 coolant could, in itself, provide all of the elements of a fire hazard if it leaked onto electrical equipment.

Finding

Water/glycol was combustible, although not easily ignited.

Determination

Leakage of water/glycol in the cabin would increase risk of fire.

Finding

Deficiencies in design, manufacture, and quality control were found in the postfire inspection of the wire installation.

Determination

There was an undesirable risk exposure, which should have been prevented by both the contractor and the government.

Finding

The spacecraft atmosphere control system design was based on providing a pure oxygen environment.

Determination

The technology was so complex that, to provide diluent gases, duplication of the atmosphere control components as well as addition of a mechanism for oxygen partial-pressure control would be required. These additions would introduce additional crew-safety failure modes into the flight systems.

Finding

Sixty seconds were required for unaided crew egress from the CM. The hatch could not be opened with positive cabin pressure above approximately 0.17 newtons per sq cm (0.25 psi). The vent capacity was insufficient to accommodate the pressure buildup in the Apollo 204 spacecraft.

Determination

Even under optimum conditions emergency crew egress from Apollo 204 spacecraft could not have been accomplished in sufficient time.

Finding

During the January 27 Apollo 204 test, difficulty was experienced in communicating from ground to spacecraft and among ground stations.

Determination

The ground system design was not compatible with operational requirements.

The final report of the Medical Analysis Panel (No. 11) to the Apollo 204 Review Board was processed for printing. The panel had been assigned to provide a summary of medical facts with appropriate medical analysis for investigation of the January 27 fire. Examples were cause of death, pathological evidence of overpressure, and any other areas of technical value in determining the cause of accident or in establishing corrective action.

The panel report indicated that at the time of the accident two NASA physicians were in the blockhouse monitoring data from the senior pilot. Upon hearing the first voice transmission indicating fire, the senior NASA physician turned from the biomedical console to look at the bank of television monitors. When his attention returned to the console the bioinstrumentation data had stopped. The biomedical engineer in the Acceptance Checkout Equipment (ACE) Control Room called the senior medical officer for instructions. He was told to make the necessary alarms and informed that the senior medical officer was leaving his console. The two NASA physicians left the blockhouse for the base of the umbilical tower and arrived there shortly before ambulances and a Pan American physician arrived at 6:43 p.m. The three physicians went to the spacecraft; time of their arrival at the White Room was estimated to be 6:45 p.m. EST.

By this time some 12 to 15 minutes had elapsed since the fire began. After a quick evaluation it was evident that the crew had not survived the heat, smoke, and burns and it was decided that nothing could be gained by attempting immediate egress and resuscitation.

Panel 11's 24 findings included:

Finding

Biomedical data at the time of the accident were received from only the senior pilot. The data consisted of one lead of electrocardiogram, one lead of phonocardiogram, and impedance pneumogram (respiration). The data was received by telemetry and from the onboard medical data acquisition system.

Determination

This configuration was normal for the test.

Finding

At 6:31:04 p.m. there was a marked change in the senior pilot's respiratory and heart rates on the biomedical tape. There was also evidence of muscle activity in the electrocardiogram and evidence of motion in the phonocardiogram. The heart rate continued to climb until loss of signal.

Determination

This physiological response is compatible with the realization of an emergency situation.

Finding

Voice contact with the crew was maintained until 6:31:22.7

Determination

At least one crew member was conscious until that time.

Finding

Hatches were opened at approximately 6:36 p.m. and no signs of life were detected. Three physicians looked at the suited bodies at approximately 6:45 p.m. and decided that resuscitation efforts would be to no avail.

Determination

Time of death could not be determined from this finding.

Finding

"The cause of death of the Apollo 204 Crew was asphyxia due to inhalation of toxic gases due to fire. Contributory cause of death was thermal burns."

Determination

It could be concluded that death occurred rapidly and that unconsciousness preceded death by some increment of time. The fact that an equilibrium had not been established throughout the circulatory system indicated that blood circulation stopped rather abruptly before an equilibrium could be reached.

Finding

Panel 5 had estimated that significant levels (more than two percent) of carbon monoxide were in the spacecraft atmosphere by 6:31:30 p.m. EST. By this time at least one spacesuit had failed, introducing cabin gases to all suit loops.

Determination

The crew was exposed to a lethal atmosphere when the first suit was breached.

Finding

The distribution of carbon monoxide in body organs indicated that circulation stopped rather abruptly when high levels of carboxyhemoglobin reached the heart.

Determination

Loss of consciousness was caused by cerebral hypoxia due to cardiac arrest from myocardial hypoxia. Factors of temperature, pressure, and environmental concentrations of carbon monoxide, carbon dioxide, oxygen, and pulmonary irritants were changing at extremely rapid rates. It was impossible from available information to integrate these variables with the dynamic physiological and metabolic conditions they produced, to arrive at a precise statement of the time when consciousness was lost and when death supervened. Loss of consciousness was estimated as at between 15 and 30 seconds after the first suit failed. Chances of resuscitation decreased rapidly thereafter and were irrevocably lost within 4 minutes.

Finding

The purge with 100-percent oxygen at above sea-level pressure contributed to the propagation of fire in the Apollo 204 spacecraft.

Determination

The oxygen level was the planned cabin environment for testing and launch, since prelaunch denitrogenation was necessary to forestall the possibility of the astronauts' suffering the bends. A comprehensive review of operational and physiological tradeoffs of various methods of denitrogenation was in progress.

The mission profile for the first manned Apollo flight would be based on that specified in Appendix AS-204 in the Apollo Flight Mission Assignments Document dated November 1966, the three manned space flight Centers were informed. Apollo Program Director Samuel C. Phillips said the complexity of the mission was to be limited to that previously planned, and therefore consideration of a rendezvous exercise would be dependent upon the degree of complication imposed on the mission. "There will be no additions that require major new commitments such as opening a CM hatch in space or exercising the docking subsystem."

MSC submitted requirements to KSC that TV signals from cameras inside the LM and CM be monitored and recorded during manned hazardous tests, with hatch open or closed, and tests in the Vehicle Assembly Building, launch pads, and altitude chambers. A facility camera was to monitor the propellant-utilization gauging system during propellant loading. MSC specified that the field of view of the TV camera should encompass the shoulder and torso and portions of the legs of personnel at the normal flight stations in both the CM and the LM.

ASPO Manager George M. Low issued instructions that the changes and actions to be carried out by MSC as a result of the AS-204 accident investigation were the responsibility of CSM Manager Kenneth S. Kleinknecht. The changes and actions were summarized in Apollo Program Directive No. 29, dated July 6, 1967.

ASPO Manager George Low, commented on control of Apollo spacecraft weight. Following the January 1967 spacecraft fire at Cape Kennedy, there had been substantial initial weight growth in the CSM. This was attributed to such items as the new CSM hatch, the flammability changes, and the additional flight safety changes. In mid-1967 the CSM weight stabilized and from then on showed a downward trend. The LM weight stabilized in mid1968 and since that time had remained fairly constant. Conclusions were that the program redefinition had caused a larger weight increase than expected, but that once the weight control system became fully effective, it was possible to maintain a weight that was essentially constant. Low told Caldwell C. Johnson, Jr., of the MSC Spacecraft Design Division that the weight control was in part due to Johnson's strong inputs in early 1968. Johnson responded, "Your control of Apollo weight growth has destroyed my reputation as a weight forecaster - but I'm rather glad."

Microscopic examination of dust particles collected from the spacecraft after the Apollo 10 mission and of samples collected from the inside of nine garments worn by the Apollo 10 astronauts confirmed preliminary findings that the itching experienced by the astronauts was due to the insulation in the tunnel hatch of the command module. Investigation showed the fiberglass insulation had flaked off during LM pressurization. Review of thermal conditions indicated the insulation was not essential and it was eliminated from future vehicles.

During the Apollo 11 management debriefing, the ASPO Manager noted a number of items requiring investigation. During separation from the S-IVB stage, the CSM autopilot apparently had difficulty determining direction of rotation. After the CSM hatch removal, there was a strong odor of burnt material in the tunnel. The leveling device on one of the experiment packages did not work. The closeup stereo camera was hard to operate and tended to fall over. The temperature in the lunar module was too cold during sleep periods. The biological isolation garment was uncomfortably hot and its visor fogged. The crew observed flashes at the rate of about one per minute in the command module at night.