North American gave a presentation at MSC on the block change concept with emphasis on Block II CSM changes. These were defined as modifications necessary for compatibility with the LEM, structural changes to reduce weight or improve CSM center of gravity, and critical systems changes. (Block I spacecraft would carry no rendezvous and docking equipment and would be earth-orbital only. Block II spacecraft would be flight-ready vehicles with the final design configuration for the lunar missions.)

NASA and North American discussed visibility requirements on the CM and came to the following conclusions: the contractor would provide four portholes in the protective shroud so the astronauts could see through both side and forward viewing windows, and ensure that all windows were clean after launch escape tower separation. North American proposed the addition to Block II CM of a collimated optical device for orientation and alignment during docking. MSC Flight Crew Operations Directorate recommended that mirrors be added to increase external and internal field of vision.

The Block II CSM configuration was based on three classes of changes: mandatory changes necessary to meet the

1. Functional requirements of the lunar mission.
2. Manufacturing or fabrication changes (identified only with improved fabrication techniques).
3. Technically desirable and weight reduction changes.

North American held a design review of the CM heatshield substructure. Use of titanium in place of stainless steel was being evaluated as part of a weight reduction study for the Block II spacecraft. Added reliability and a weight saving of several hundred pounds might be achieved thereby. Three factors would be considered: the brittleness of stainless steel at extremely cold temperatures, the higher cost of titanium, and the verification of diffusion bonding of titanium honeycomb.

To verify a narrower hatch configuration proposed for Block II spacecraft, North American evaluated the capability of an astronaut wearing a pressurized space suit and a portable life support system to pass through the main hatch of the CM for extravehicular activities. Subjects were able to enter and leave the mockup without undue difficulty despite the presence of gravity.

At the April 7-8 NASA-North American Technical Management Meeting (the first of these meetings to be held at MSC's new home, "NASA Clear Lake Site 1"), ASPO Manager Joseph F. Shea summarized his office's recent activities concerning the Block II spacecraft. He spelled out those areas that ASPO was investigating - which included virtually the whole vehicle between escape tower and service engine bell. Shea outlined procedures for "customer and contractor" to work out the definitive Block II design, aiming at a target date of mid-May 1965. These procedures included NASA's giving North American descriptions of its Block II work, estimates of weight reduction, and a set of ground rules for the Block II design. And to ensure that both sides cooperated as closely as possible in this work, Shea named Owen E. Maynard, Chief of MSC's Systems Engineering Division, and his counterpart at Downey, Norman J. Ryker, Jr., to "honcho" the effort.

ASPO asked North American to investigate the possibility of designing apex-upright, stable flotation attitude into Block I and Block II CM's.

North American conducted a preliminary study on removal of one of three fuel cells from the Block II CSM. The contractor predicted a total weight saving of about 168 kilograms (370 pounds), with potential indirect reductions in the cryogenic systems, but this change would require a significant increase in reliability.

Joseph F. Shea, ASPO Manager, in a letter to North American's Apollo Program Manager, summarized MSC's review of the weight status of the Block I and the design changes projected for Block II CSM's.

The Block II design arose from the need to add docking and crew transfer capability to the CM. Reduction of the CM control weight (from 9,500 to 9,100 kilograms (21,000 to 20,000 pounds)) and deficiencies in several major subsystems added to the scope of the redesign.

Redesign of the CM would cause a number of changes above the deck, although ASPO believed that the 73.7-centimeter (29-inch)-diameter tunnel could be retained and tunnel access might be improved if the restrictions for seating the hatches were removed. Other changes not related to the docking and transfer requirement would be considered as long as they did not affect the structure below the deck.

Changes below the deck would be kept to a minimum on both the inner and the outer structure. Anything which might invalidate the applicability of the Block I lunar reentry tests to the Block II design would not be changed.

ASPO wanted to evaluate a preliminary design of the CM in which the only access to the LEM would be by extravehicular transfer. Although this approach was not currently considered operationally acceptable, any gains from such a design should be studied.

ASPO agreed that the CM thermal protection would be enhanced by addition of a boost protective cover for both Block I and Block II. A "soft" cover should be simple to design and operate, and a boost cover would permit coating the CM with a thermally efficient surface. This, with the help of attitude programming, should permit North American to reduce the initial ablator bond line temperature from 394 K (250 degrees F) to below 338 K (150 degrees F). ASPO also asked the contractor to consider raising the bond line temperature on the blunt face from 590 K (600 degrees F to 700 K (800 degrees F). These changes would reduce ablator weight significantly.

To eliminate the humidity problem in the Block I subsystems, ASPO believed that electronic repackaging would be required. Such a redesign should take advantage of ASPO's decision to eliminate onboard maintenance as an acceptable means of achieving mission reliability. A more efficient mounting arrangement should be considered in conjunction with electronic system repackaging. Elimination of onboard maintenance would change requirements on the inflight test system; perhaps that system could be eliminated from the spacecraft.

The biggest uncertainty in weight requirements was meteoroid protection. The design approach to this problem should be incorporated with a redesign of the SM to reduce both the tank size and structure (but see August 6 statement of Robert O. Piland) consistent with a 16,800-kilogram (39,000-pound) consumable fuel load, rather than the current 20,400-kilogram (45,000-pound) capacity, The SM design concept should remain the same, but North American should use this opportunity to clean up several structural details.

The SM thermal control system should be passive. Spacecraft orientation, either on a semicontinuous or discrete attitude program, would be permissible to maintain necessary temperature limits. To reach acceptable thermal time constants, the reaction control system (RCS) might have to be modified. It might also be desirable to change the RCS fuel to monomethylhydrazine.

Because of the large amount of spacecraft wiring, North American was asked to study using smaller sizes and reduced insulation thicknesses.

Another consideration was reducing the lunar mission time from 14 days to the reference mission length of about 10 days. But the current tank sizes should be maintained and the spacecraft should be capable of 14- day earth orbital missions with three men. The velocity reserve in the RCS might be decreased if the attitude requirements for guidance and navigation were eased. Here, also, the current tank sizes should not be changed.

Other major changes (such as redesign of the fuel cell, incorporation of new heatshield material, cryogenic helium pressures, and adapter staging) could be considered in the redesign; they would, however, be approved only if the foregoing changes did not provide sufficient weight margin.

ASPO would require a complete preliminary design and impact assessment of the Block II spacecraft before its incorporation into the program would be authorized.

NASA directed North American Aviation, Inc. (NAA), to make certain mandatory changes to both Block I and Block II spacecraft systems.

NAA conducted formal inspection and review of Block II CSM mockup.

MSC's Apollo Spacecraft Program Office (ASPO) approved a plan (put forward by the MSC Advanced Spacecraft Technology Division to verify the CM's radiation shielding. Checkout of the radiation instrumentation would be made during manned earth orbital flights. The spacecraft would then be subjected to a radiation environment during the first two unmanned Saturn V flights. These missions, 501 and 502, with apogees of about 18,520 km (10,000 nm), would verify the shielding. Gamma probe verification, using spacecraft 008, would be performed in Houston during 1966. Only Block I CM's would be used in these ground and flight tests. Radiation shielding would be unaffected by the change to Block II status.

North American representatives visited the Grumman plant to discuss design features and to inspect the electroluminescent lighting on the LEM. North American intended to adopt this same feature on Block II CMs.

North American and MIT Instrumentation Laboratory representatives met in Houston to discuss electrical power requirements for the guidance and control systems in Block II CMs. They had determined the additional electrical power needed for the guidance and control system 24 volts was available,

Eagle-Picher Company completed qualification testing on the 25-amperehour reentry batteries for the CM. Shortly thereafter, Eagle-Picher received authorization from North American to proceed with design and development of the larger 40-ampere-hour batteries needed for the later Block I and all Block II spacecraft.

The Guidance and Control Implementation Sub-Panel of the MSC-MSFC Flight Mechanics Panel defined the guidance and control interfaces for Block I and II missions. In Block II missions the CSM's guidance system would guide the three stages of the Saturn V vehicle; it would control the S- IVB (third stage) and the CSM while in earth orbit; and it would perform the injection into a lunar trajectory. In all of this, the CSM guidance backed up the Saturn ST-124 platform. Actual sequencing was performed by the Saturn V computer.

North American and Honeywell reviewed the Block II CSM entry monitor subsystem's compatibility with the stabilization and control system. The proposed configuration, they found, combined maximum reliability with minimum size and weight and would provide adequate mission performance.

ASPO's Operations Planning Division defined the current Apollo mission programming as envisioned by MSC. The overall Apollo flight program was described in terms of its major phases: Little Joe II flights (unmanned Little Joe II development and launch escape vehicle development); Saturn IB flights (unmanned Saturn IB and Block I CSM development, Block I CSM earth orbital operations, unmanned LEM development, and manned Block II CSM/LEM earth orbital operations); and Saturn V flights (unmanned Saturn V and Block II CSM development, manned Block II CSM/LEM earth orbital operations, and manned lunar missions).

After studying the merits of three flush-mounted versus two scimitar VHF antennas for the Block II CSM, the MSC Instrumentation and Electronics Systems Division recommended the flush-mounted type.

MSC informed North American that a flashing light on the CSM, as an aid for visual rendezvous, was not required. (A request for some such device had been generated at the Block II mockup review.) Houston's position was based on the current CSM/LEM configuration, which called for rendezvous radar on both spacecraft and the ability of both vehicles to effect the rendezvous using either its own radar or that in the target vehicle.

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.

Officials from North American and MSC Crew Systems Division defined the container design and stowage of survival kits in the Block II CM. The equipment would be packed in fabric rucksacks and would be installed in the spacecraft's stowage compartment. (This method eliminated a removable hard container used in the Block I vehicle and would save weight.)

North American received NASA's formal go-ahead on manufacture of the Block II spacecraft.

MSC informed North American that the Center would furnish a VHF transmitter to serve as a telemetry dump for all manned Block I flights. This would permit wide flexibility in testing the CSM S-band's compatibility with the Manned Space Flight Network prior to Block II missions.

The Configuration Control Panel approved a deployment angle of 45 degrees for the adapter panels on Block I flights. North American anticipated no schedule impact. MSC and North American were jointly evaluating the acceptability of this angle for Block II missions as well. A most important consideration was the necessity to communicate via the CM's high-gain antenna during the transposition and docking phase of the flight.

MSC approved plans put forth by North American for mockups of the Block II CSM. For the crew compartment mockup, the company proposed using the metal shell that had originally been planned as a simulator. Except for the transfer tunnel and lighting, it would be complete, including mockups of all crew equipment.

Mockup 12, the Block I lighting tool, would be modified to conform to the interior of Block II spacecraft.

Systems Engineering Division reported the latest review schedule for the Block II mockups:

- March 15, 1965 - crew compartment
- April 30, 1965 - interior lighting
- July 15, 1965 - Design Engineering Inspection (DEI)
- August 6, 1965 - lighting DEI

Crew Systems Division received from North American a mockup of the proposed design of the food stowage compartment in the Block II CSM. This article would be used for packaging studies in preparation for the lower equipment bay mockup review in February.

Ling-Temco-Vought began large-scale developmental testing of the radiator for the Block II CSM environmental control system. One problem immediately apparent was the radiator's performance under extreme conditions.

ASPO's Systems Engineering Division (SED) investigated the possibility of partial donning of the space suit (sans helmet and gloves) and the consequent effects upon operation of the CM environmental control system (ECS). (Current ECS design called for shirtsleeve and full-suited operations.) The systems engineers found that, with vehicle reliability based upon shirtsleeve environments, wearing part of the suit contributed little toward protecting the astronaut against loss of cabin pressure.

Most pressure-seal failures in the spacecraft would still allow the astronaut time to don the complete suit. Catastrophic failures (i.e., loss of windows or hatches) were highly improbable, but if one of this type occurred, depressurization would be so rapid as to preclude the astronaut's donning even a part of the suit. Actually, overall mission reliability was greatest with the shirtsleeve environment; continuous suit wear degraded the garment's reliability for the lunar exploration phase of the flight. Moreover, a number of design changes in the spacecraft would be required by partial suit wear.

SED concluded that, to build confidence in the spacecraft's pressurization system, Block I CM's should be outfitted for partial suit wear. In Block II vehicles the suit should not be worn during translunar mission phases (again because of mission reliability). SED recommended to the ASPO Manager, therefore, that he direct North American to incorporate provisions for partial suit wear in Block I and to retain the shirtsleeve concept for the Block II spacecraft.

The Preliminary Design Review of the Block II CM was held at North American's Downey, Calif., plant. Ten working groups evaluated the spacecraft design and resolved numerous minor details. They then reported to a review board of NASA and North American officials.

This board met in Houston during the middle of the month, reviewed the findings of the working groups, and submitted recommendations to ASPO. Several significant problems required the attention of Apollo managers at Houston and at North American:

- The effect of heavyweight LEM (up 1,361 kg (3,000 lbs)) on the spacecraft lunar adapter and on the CM's docking system. North American was studying this problem already.
- Wearing cycles and requirements for donning and stowage of the space suits must be resolved and incorporated into the CSM specifications. North American's interpretation of those specifications conflicted with the MSC Crew System Division's current plan that, during the first several missions, all three crewmen should be able to wear their suits without the helmets.

The first meeting of the Configuration Control Board was held at MSC with ASPO Manager Joseph F. Shea as chairman. Approval was given to delete 10 Apollo guidance and navigation systems; and W. F. Rector III was directed to look into the use of computers and prototype units for electronic systems integration. In other actions, a decision on changes to CSM specifications to provide for the heavyweight LEM (a proposed increase from 12,705 to 14,515 kg (28,000 to 32,000 lbs)) was deferred until the next meeting; and Owen Maynard was directed to identify all Block II changes that must be implemented regardless of impact and have them ready for Board action by February 18, 1965.

MSC was studying several approaches to the problems of automatic thermal control and automatic reacquisition of the earth by the S-band high-gain antenna while the CSM circled the moon. (The Block II spacecraft, MSC had stated, must have the ability to perform these functions wholly on its own. During an extended stay of the LEM on the lunar surface, when the CSM pilot needed uninterrupted sleep periods, antenna reacquisition was absolutely essential for telemetering data back to earth. And although the requirements for passive thermal control were not yet well defined, the spacecraft's attitude must likewise be automatically controlled.)

Robert C. Duncan, chief of the MSC Guidance and Control Division, presented his section's recommendations for solving these problems, which ultimately won ASPO's concurrence. Precise spacecraft body rates, Duncan said, should be maintained by the stabilization and control system. The position of the S-band antenna should be telemetered to the ground, where the angle required for reacquisition would be computed. The antenna would then be repositioned by commands sent through the updata link.

MSC negotiated a backup Block II space suit development program with David Clark Company, which paralleled the Hamilton Standard program, at a cost of $176,000. Criteria for selecting the suit for ultimate development for Block II would be taken from the Extravehicular Mobility Unit Design and Performance Specification. A selection test program would be conducted at MSC using the CM mockup, the lunar simulation facility, and the LEM mockup.

MSC canceled plans (originally proposed by North American) for a device to detect failures in the reaction control system (RCS) for Block I CSMs. This was done partly because of impending weight, cost, and schedule penalties, but also because, given an RCS failure during earth orbit, the crew could detect it in time to return to earth safely even without the proposed device. This action in no way affected the effort to devise such a detection system for the Block II CSM or the LEM, however.

MSC relayed to NASA Headquarters North American's cost estimates for airlocks on the Apollo CM:

Spacecraft	Development	Unit Cost
Block I	$840,000	$185,000
Block II	$960,000	$112,000
Blocks I & II	$1,050,000	$111,000

(The unit costs presumed two flight items for Block I and 12 for Block II spacecraft.)

During late February and early March, North American completed a conceptual design study of an airlock for the Block I CMs. Designers found that such a device could be incorporated into the side access hatch. A substitute cover for the inner hatch and a panel to replace the window on the outer hatch would have to be developed, but these modifications would not interfere with the basic design of the spacecraft.

MSC directed North American to delete the rendezvous radar from Block II CSMs. On those spacecraft North American instead would install LEM rendezvous radar transponders. Grumman, in turn, was ordered to halt its work on the CSM rendezvous radar (both in-house and at RCA) as well as all support efforts. At the same time, however, the company was directed to incorporate a tracking light on the LEM (compatible with the CSM telescope sextant) and to modify the spacecraft's VHF equipment to permit range extraction in the CSM.

To eliminate interference between the S-IVB stage and the instrument unit, MSC directed North American to modify the deployment angle of the adapter panels. Originally designed to rotate 170 degrees, the panels should open but 45 degrees (60 degrees during abort), where they were to be secured while the CSM docked with and extracted the LEM.

But at this smaller angle, the panels now blocked the CM's four flush- mounted omnidirectional antennas, used during near-earth phases of the mission. While turning around and docking, the astronauts thus had to communicate with the ground via the steerable high gain antenna. For Block II spacecraft, therefore, MSC concurrently ordered North American to broaden the S-band equipment's capability to permit it to operate within 4,630 km (2,500 nm) of earth.

Researchers at Ames Research Center began testing the stability of the Block II CM and escape tower (with canards) in the Center's wind tunnel. Tests would be conducted on the CM itself and while mated with the tower.

ASPO proposed deletion of a liftoff light in the Block II CM. The Block I design provided a redundant panel light which came ON at liftoff as a part of the emergency detection system (EDS). This light gave a cue to the pilot to verify enabling of the EDS automatic abort, for which manual backup was provided. The Block II CM would incorporate improved EDS circuitry without manual backup. Deletion of the liftoff light in the CM was proposed to save weight, power, space, and reliability, and to eliminate a crew distraction during the boost phase of flight.

Structures and Mechanics Division engineers were studying several schemes for achieving the optimum weight of Block II CMs without compromising landing reliability: reducing velocity by retrorockets or "explosions" in the parachutes; controlling roll attitude to 0 degrees at impact through a "rotatable pot" structure; changing landing medium (i.e., shape hole in water and/or aeration of the water).

Part I of the Critical Design Review of the crew compartment and the docking system in the Block II CM was held at North American. Systems Engineering (SED) and Structures and Mechanics (SMD) divisions, respectively, evaluated the two areas.

- Crew compartment:

- The restraint harness, acceptable in the Block I vehicle, interfered with attachments for the suit umbilicals. These attachments were critical for suit ventilation and mobility; the harness location was likewise critical for crew impact tolerances. Evaluation of alternate locations for the harness and umbilical fittings - or both - awaited the availability of a couch mockup. Manned sled tests might be needed to verify any harness changes.
- Restraints at the sleep station must be redesigned. At present, they did not allow sufficient room for a crewman in his pressure suit.
- To save weight, North American planned to strap crew equipment to shelves and bulkheads (rather than stowing such gear in compartments, as was done on the Block I vehicle).
- Most serious, in an earth landing, when the attenuator struts compressed, the couches would strike a portable life support system (PLSS). "No analysis has been made," SED reported, "to show that this is acceptable." For in such an occurrence, the crew could be injured or killed, the oxygen tank in the PLSS (under about 409 kg (900 lbs) of pressure) could explode, and the aft bulkhead might be ruptured. North American was scheduled to report on this problem on April 27.

- Docking system:

- SMD approved the probe and drogue concept, but recommended that fittings be standardized throughout (so that only one tool was needed).
- The division also approved North American's design for the outer side hatch (i.e., limiting its deployment to 90 degrees), pending MSC's final word on deployment requirements.
- The division recommended that the forward hatch mechanism be simplified. (North American warned of schedule delays.)

North American completed negotiations with Ling-Temco-Vought for design support on the environmental control radiators for Block II CSMs.

North American summarized its position on the design of the CM for earth impact in a letter to MSC. A number of meetings had taken place since the NASA North American Technical Management Meeting February 25, 1964, at which the decision was made to reorient Apollo impact to water as the primary landing site.

The letter reviewed the history of boilerplate 28 drop tests and a series of MSC North American meetings during the last two months of 1964 and the first two of 1965. On February 12, at a meeting at Downey, California, North American had recommended:

• Design for 0.99999 criteria.
• Retain the 27.5 degrees hang angle to eliminate the requirement for redesign of upper crew compartment side wall. The dual hang angle configuration should be eliminated for spacecraft 017 and subsequently through Block II.
• Allow plastic deformation of the aft heatshield.
• Continue investigation of possible upper deck and tunnel problems.
• Fly spacecraft 009 with a probability of success at water impact of 0.999, and continue boilerplate 28 testing to give assurance of meeting this criterion.

At the time of the April 27 letter, North American was implementing the design changes defined in the Apollo CM design changes for water impact. The changes were based on North American's best understanding of agreements between it and MSC regarding criteria, loads, definition of the ultimate land envelope, structural analysis, and the requirement that no-leakage integrity within the ultimate load level be demonstrated by test.

Part II of the Critical Design Review of the crew compartment and docking system for the Block II CM was held at Downey, California, using mockups 28 and 27 A. (Part I had been held on March 23-24.)

- Systems Engineering Division reported 49 design changes were requested in the crew compartment, 45 of which were acted upon. The two most serious problems were:

- stowage of the portable life support systems;
- and the crewmen's knees striking the main display console at impact.

- Structures and Mechanics Division reported a number of minor changes to the docking system, primarily to simplify crew transfer and operation of the hatch mechanisms.
- Crew Systems Division (CSD) engineers evaluated the compatibility of the space suit and MSC's new in- house helmet with the Block II spacecraft. CSD reported that the suits were sufficiently mobile and afforded adequate visibility; problems with the shoulders, experienced in early versions of the suit, had been solved; and while the three crewmen still quite literally rubbed elbows, this problem also had been alleviated and no longer hampered the crew's performance.

Although North American was including real-time digital command equipment in Block II CSMs (as NASA had directed), the firm recommended that such equipment not be placed on Block I vehicles. North American based their contention on two factors:

1. the anticipated cost and schedule impacts; and
2. command capability was not essential during earth orbital flights.

In response to a query, Apollo Program Director Samuel C. Phillips told NASA Associate Administrator for Manned Space Flight George E. Mueller that plans to use VHF communications between the CSM, LEM, and extravehicular astronauts and to use X-band radar for the CSM/LEM tracking were reviewed. Bellcomm reexamined the merits of using the Unified S-Band (USB) type which would be installed in the CSM and LEM for communication with and tracking by the earth.

It was found that no appreciable weight saving or weight penalty would result from an all USB system in the Apollo spacecraft. Also, it was determined there would be no significant advantage or disadvantage in using the system. It was noted, however, that implementation of an all S-band system at that stage of development of the design of the CSM, LEM, and astronaut equipment would incur an obvious cost and schedule penalty.

Memorandum, Phillips to Mueller, "Use of Only Unified S-Band Communication Equipment in Apollo Spacecraft," May 5, 1965.

May 6

After lengthy investigations of cost and schedule impacts, MSC directed North American to incorporate airlocks on CMs 008 and 014, 101 through 112, and 2H-1 and 2TV-1. The device would enable astronauts to conduct experiments in space without having to leave their vehicle. Initially, the standard hatches and those with airlocks were to be interchangeable on Block II spacecraft. During October, however, this concept was changed: the standard outer hatch would be structured to permit incorporation of an airlock through the use of a conversion kit (included as part of the airlock assembly); and when an airlock was installed, an interchangeable inner hatch would replace the standard one.

To broaden communications capabilities during near-earth phases of a mission, the S-band omnidirectional antennas on all Block II CMs were moved to the toroidal (doughnut-shaped) section of the forward heatshield.

MSC directed North American to install Block II-type, flush-mounted omni-directional S-band antennas on CMs 017 and 020. These antennas would survive reentry and thus would afford telemetry transmissions throughout the flight. On June 25, the Center ordered that they be installed in the toroidal (doughnut shaped) section of the aft heatshield.

To aid reacquisition and tracking of the high-gain antenna, MSC directed North American to study the feasibility of an inertial reference system on Block II spacecraft, one that would use rate signals from the CSM's stabilization and control system. Without this system, the astronauts would have to perform anywhere from 250 to 500 antenna reacquisitions during a single lunar mission. And during sleeping periods, when the CM pilot was alone in the vehicle, it was mandatory that the antenna automatically reacquire the earth.

ASPO Manager Joseph F. Shea replied to a recommendation by the Assistant Director for Flight Operations to incorporate warning lights in Block I and II CMs to indicate failure of the gimbal actuator secondary drive motors. ASPO decided that no failure indication would be provided for the redundant drive motors in Block I spacecraft because:

1. in-flight checkout procedures would provide for exercising the gimbal actuators by the primary and secondary drive motors prior to service propulsion system burns; and
2. all manned Block I missions would be conducted in earth orbit and reaction control system deorbit capability was stipulated.

ASPO advised North American that, at present, no unmanned flights were planned for the Block II CM. After the company concluded its own analysis of Apollo requirements, MSC would determine whether the heatshield must be verified prior to manned missions. But because of the long "lead time" involved, North American should continue securing the requisite instrumentation pending a final decision.

MSC directed NAA to make a "predesign" study of a rocket landing system for the Block II CM. (The Center had already studied the system's feasibility and had conducted full-scale drop tests.)

MSC reviewed a lighting mockup of the crew compartment in the Block II CM. The design concept, though needing further refinement, was deemed acceptable. Engineers from Crew Systems Division found that lights on the fingertips of the suit gloves worked quite well; optimum positioning was as yet undetermined, however. At the same time, MSC reviewed the design of the Block I side hatch (i.e., not modified to meet Block II extravehicular requirements). Reviewers found North American's major problems were warpage and crew ingress from space. Further, the design of both side hatches needed "additional coordination" with that of the umbilical access arm of the launch tower to ensure compatibility.

MSC and North American discussed the brittleness of the boost protective cover and the possibility that, during tower jettison or abort, the cover might break up and cause damage to the spacecraft. Having investigated a number of various materials and construction techniques, North American recommended adding a nylon fabric to strengthen the structure. Company engineers believed that, thus reinforced, the cover would be less likely to tear apart in flight. Even though this would increase the weight of the cover by about 27 kg (60 lbs), MSC concurred. The change applied to both Block I and Block II CMs, and was effective for spacecraft 002, 009, and all subsequent vehicles.

Independent studies were made at MSC and North American to determine effects and impact of off-loading certain Block II service propulsion system components for Saturn IB missions. The contractor was requested to determine the weight change involved and schedule and cost impact of removing one oxidizer tank, one fuel tank, one helium tank and all associated hardware (fuel and oxidizer transfer lines, propellant quantity sensors and certain gaging wire harnesses) from CSM 101 and CSM 103. The MSC study was oriented toward determining technical problems associated with such a change and the effects on spacecraft operational requirements. The North American study indicated that removing the equipment would save about 690 000, along with a weight reduction of approximately 454 kg (1,000 lbs).

Their report also indicated there would be no schedule impact provided go-ahead was given for CSM 101 prior to June 1, 1965, and for CSM 103 prior to November 1, 1965.

The MSC study indicated a maximum burn limitation of 280 seconds, due to excessive drop in helium temperature; and also pointed out that the change to the gaging system might not be as simple as North American stated because of the arrangement of the secondary sensing system. However, those problems did not appear insurmountable.

North American submitted a design proposal for a scientific airlock for the CM (applicable to 014 and all Block II spacecraft). Structural design was scheduled to begin shortly.

The operational requirement for Block I and Block II CSM HE orbital communications capability was investigated. ASPO requested that appropriate contract direction and specification change notices be submitted immediately to eliminate this capability from the Block II CSM and the practicality of eliminating the HE orbital capability from the Block I CSM be investigated.

Structures and Mechanics Division (SMD) presented meteoroid protection figures for the Apollo CSM. (During April, General Electric (GE) had developed reliability estimates for the LEM, based on revised design criteria, for the 8.3-day reference mission. The probability for mission success, GE had found, was 0.9969.) SMD'S figures were:

	Block I (14-day earth orbital flight)	Block II (8.3-day lunar mission)
CM	0.99987	0.99989
SM	0.9943	0.9941

The division consequently placed the meteoroid protection for the entire mission at 0.99417 (Block I, CSM only) and 0.99089 (Block II, CSM and LEM). Apollo's goal was 0.99.

All of the above figures, both GE's and SMD's, were derived from the inherent protection afforded by the spacecraft's structure. Thus no additional meteoroid shielding was needed. (Meteoroid protection would still be required, of course, during extravehicular operations.)

North American began redesigning the side hatch mechanism in the CM to satisfy the requirement for extravehicular transfer from Block II spacecraft. Two basic modifications to the Block I mechanism were required: (1) enlarging it to overcome thermal warpage; and (2) adding some hinge retention device to secure the hatch once it was opened.

NASA Headquarters authorized North American to subcontract the Block II CSM fuel cells to Pratt and Whitney. Estimates placed the cost at $30 million.

North American and MSC attended a design review at Ling-Temco-Vought on the environmental control system radiator for the Block II CSM. After reviewing design and performance analyses, the review team approved changes in testing and fabrication of test hardware.

Joseph F. Shea, ASPO Manager, summarized ground rules on the schedules for qualifying and delivering equipment for Block II spacecraft,

- All components installed on the Block II test vehicle (2TV-1) and on Block II flight vehicles must be production hardware. (Prototype units were unacceptable.)
- Any changes from the configuration of CSM 103 in 2TV-1, 101, or 102 must be essential to the specific mission requirements of those vehicles.
- Delivery schedules must be compatible with North American's needs. (North American was allowed some leeway in installing components, provided that such reordering was feasible and did not affect overall checkout and delivery schedules for the vehicle.)
- Qualification testing must be scheduled so that all equipment was qualified before February 15, 1967.
- Launch-constraining ground tests must be scheduled for completion at least six weeks before that launch.

Shea alone had authority to waive these schedule rules.

North American and its subcontractor, LTV, conducted a design review on the environmental control system radiator for the Block II CSM. Both parties agreed upon a backup effort (i.e., a narrower selective stagnation panel), which would be more responsive to thermal changes in the spacecraft. Testing of this backup design could follow that of the prototype and still meet the design release.

North American proposed an additional pane of glass for the windows on Block II CMs. Currently, both blocks of spacecraft had one pane. Should meteoroids pit this pane, the window could fail during reentry at lunar velocities. The meteoroid protection group in Structures and Mechanics Division were evaluating North American's proposal, which would add about 10.43 kg (23 lbs) to the vehicle's weight. No such added protection was required on Block I spacecraft.

The Critical Design Review (CDR) of the Block II CSM was scheduled to be conducted in November and December 1965, with the first phase being held November 15-18, and the second phase December 13-17.

The first phase activity would be a review of drawings, schematics, procurement specifications, weight status, interface control drawings, failure analysis, proposed specification change notices, and specification waivers and deviations. The second phase of the review would be a physical inspection of the mockup of the Block II CSM.

The review would be conducted by review teams organized in the several areas and headed by team captains, as follows: Structures and Propulsion, O. Ohlsson; Communications, Instrumentation, and Electrical Power, W. Speier; Stabilization and Control, Guidance and Navigation, A. Cohen; Crew Systems, J. Loftus; and Mission Compatibility and Operations, R. Battey.

Crew Systems Division defined the survival equipment that MSC would procure for Apollo spacecraft. Fifteen survival sets would be needed for Block I and 30 for Block II CMs.

In the absence of a firm requirement, and because of limited utility, reported Robert C. Duncan, Chief of the Guidance and Control Division, the horizon photometer and star tracker were being deleted from the primary guidance system in Block I CSMs. (Block II guidance systems would still contain the devices.)

To support studies on equipment stowage, North American agreed to maintain mockups of the crew compartments in the two blocks of CMs. The contractor's effort would be geared for the first manned flight for each series of vehicles (spacecraft 012 and 101).

MSC authorized North American to modify the Block II CSM design to provide for installation of a luminous beacon compatible with the LEM tracking system. The CSM beacon could replace the rendezvous radar and transponder.

The Block II CSM Critical Design Review (CDR) was held at North American, Downey, Calif. The specifications and drawings were reviewed and the CSM mockup inspected. Review Item Dispositions were written against the design where it failed to meet the requirements.

As a result of the CDR North American would update the configuration of mockup 27A for use in zero-g flights at Wright-Patterson AFB. The flights could not be rescheduled until MSC approved the refurbished mockup as being representative of the spacecraft configuration.

The Block II Apollo food stowage problems were explored at North American. Methods of restraint were resolved to allow accessibility of the man-meal assemblies. The contractor, Melpar, Inc., would rework and reposition mockup man-meal assemblies to conform with suggestions by the Crew Provisions Office of the MSC Apollo Support Office and North American representatives.

A decision made at a Program Management Review eliminated the requirement for a land impact program for the CM to support Block I flights. Post-abort CM land impact for Saturn IB launches had been eliminated from Complex 37 by changes to the sequence timers in the launch escape system abort mode. The Certification Test Specification and related Certification Test Requirements would reflect the new Block II land impact requirements.

NASA Hq. requested the Apollo Spacecraft Program Office at Manned Spacecraft Center to evaluate the impact, including the effect on ground support equipment and mission control, of a dual AS-207/208 flight as early as AS-207 was currently scheduled. ASPO was to assume that launch vehicle 207 would carry the Block II CSM, launch vehicle 208 would carry the lunar excursion module (LEM), and the two launches would be nearly simultaneous. Kennedy Space Center (KSC) and Marshall Space Flight Center (MSFC) were asked to make similar studies for their systems. Response was requested by February 7, 1966.

ASPO Manager Joseph F. Shea informed Apollo Program Director Samuel C. Phillips, in response to a January 28 TWX from Phillips, that MSC had evaluated the capability to support a dual launch of AS-207 208 provided an immediate go-ahead could be given to the contractors. Shea said the evaluation had covered mission planning, ground support equipment (GSE), flight hardware, and operations support. Modifications and additional GSE would be required to update Launch Complex 34 at Cape Kennedy to support a Block II CSM. The total cost of supporting the AS-207/208 dual launch was estimated at $10.2 million for the GSE and additional boiler plate CSM configuration, but Shea added that these costs could be absorbed within the FY 1966 budget. Shea recommended that the dual mission be incorporated into the program.

NASA Hq. requested the MSC Apollo Spacecraft Program Office to reassess the spacecraft control weights and delta-V budget and prepare recommendations for the first lunar landing mission weight and performance budgets. The ASPO spacecraft Weight Report for April indicated that the Block II CSM, when loaded for an 8.3-day mission, would exceed its control weights by more than 180 kilograms and the projected value would exceed the control weight by more than 630 kilograms. At the same time the LEM was reported at 495 kilograms under its control weight. Credit for LEM weight reduction had been attributed to Grumman's Super Weight Improvement Program.

ASPO Manager Joseph F. Shea informed Rocco A. Petrone, KSC, that structural problems in the CSM fuel and oxidizer tanks required standpipe modifications and that they were mandatory for Block I and Block II spacecraft. Retrofit was to be effective on CSM 011 at KSC and other vehicles at North American's plant in Downey, Calif.

In response to a query on needs for or objections to an Apollo spacecraft TV system, MSC Assistant Director for Flight Crew Operations Donald K. Slayton informed the Flight Control Division that FCOD had no operational requirements for a TV capability in either the Block I or the Block II CSM or LM. He added that his Directorate would object to interference caused by checkout, crew training, and inflight time requirements.

MSC's Director of Flight Crew Operations Donald K. Slayton said that the Block I flight crew nomenclature was suitable for the AS-204 mission, but that a more descriptive designation was desirable for Block II flights.

Block I crewmen had been called command pilot, senior pilot, and pilot. Slayton proposed that for the Block II missions the following designations and positions be used: commander, left seat at launch with center seat optional for the remainder of the CSM mission, and left seat in the LM; CSM pilot, center seat at launch with left seat optional for remainder of mission; and LM pilot in the right seat of both the CSM and LM.

MSC Director Robert R. Gilruth asked LaRC Director Floyd Thompson to conduct a study at Langley to familiarize flight crews with CM active docking and to explore problems in CM recontact with the LM and also LM withdrawal. MSC would provide astronaut and pilot-engineer support for the study. Apollo Block II missions called for CM active docking with the LM and withdrawal of the LM from the S-IVB stage, requiring development of optimum techniques and procedures to ensure crew safety and to minimize propellant utilization. LM withdrawal was a critical area because of clearances, marginal flight crew visibility, and mission constraints. Previous simulations at LaRC indicated the possibility of using the Rendezvous Docking Simulator.

H. C. Creighton, A. R. Goldenberg, and Guy N.

Witherington, all of KSC, inspected spacecraft 101 wire bundles March 29 at the request of CSM Manager Kenneth S. Kleinknecht of MSC. Kleinknecht had asked that they give him a recommendation as to whether the bundles should be removed or whether they could be repaired in place. On April 4, they reported to Kleinknecht that time had not been sufficient to determine the complete status of the wiring. A superficial inspection about five-percent complete had indicated some serious discrepancies, for which they made some recommendations, but they recommended a more detailed inspection of the spacecraft 101 wire bundles.

The Apollo 204 Review Board accepted the final report of its Design Review Panel (No.9).

The Panel's 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.

MSC ASPO Manager George M. Low told Sydney C. Jones, Jr., MSC Communications and Power Branch, that he wanted to establish two task teams on CSM electrical systems.

The first team would study the wiring harnesses on spacecraft 2TV-1 and 101 and all subsequent spacecraft to determine actions needed to save the harnesses as installed. Low asked: "Can a sufficient number of nylon wire bundle ties be replaced to meet the requirements of our new materials specification? Can silicone rubber padding and chafing guards be replaced? What fixes must be incorporated to meet requirements of the recent inspection activities? Has the harness been mistreated in recent months, as was mentioned to me by some of the astronauts? How about water glycol spillage in 101?" The task team was to include members from the Engineering and Development and Flight Crew Operations Directorates, the Flight Safety Office, and the Reliability, Quality, and Test Division. Low asked firm recommendations concerning the harnesses in spacecraft 2TV-1 and 101 by April 15 if possible.

The second task team would study flammable materials used with all other electrical systems. Low referred "specifically to the RTV (room temperature vulcanizing) used on the backs of circuit-breaker panels and elsewhere; the circuit breakers themselves; the electroluminescent panels; and any other materials generally associated with the electrical system." Low said Structures and Mechanics Division (SMD) had done some very promising work with coatings for the circuit-breaker panels but these coatings might not be applied to some of the panels because of the open mechanical elements of many of the switches. He recommended that Jones ask representatives from SMD, the Instrumentation and Electronics Systems Division, and the Flight Safety Office to work with him. Low asked Jones to let him know by April 12 when it would be possible to make specific recommendations as to what needed to be done.

NASA Task Team - Block II Redefinition, CSM, was established by ASPO. The team - to be in residence at North American Aviation during the redefinition period - was to provide timely response to questions and inputs on detail design, overall quality and reliability, test and checkout, baseline conditions, configuration control, and schedules.

Astronaut Frank Borman was named Task Team Manager and group leaders were: Design, Aaron Cohen; Quality and Reliability and Test and Checkout Procedures, Scott H. Simpkinson; Materials, Jerry W. Craig; Specifications and Configuration Control, Richard E. Lindeman; and Scheduling, Douglas R. Broome.

NASA Block II Redefinition Task Team group leaders and CSM Program Manager Kenneth S. Kleinknecht arrived at North American Aviation Space Division at Downey May 2, followed by Task Team Manager Frank Borman the next day.

Borman met with North American management May 4 to ensure understanding of the team plan and objectives. An afternoon meeting with NASA and North American Task Managers and group leaders reviewed the status of the Block II Redefinition task.

Following is a summation of the technical status at the time:

- Ninety-five percent of the wires and break points had been defined, including additional wires for changes (approximately 200) plus the existing open items on spacecraft 101. Schematics for manufacturing and preparation of integrated schematics were to be available May 30.

- AiResearch environmental control system components had been reviewed by North American and direction transmitted for materials changes.

- North American was planning no compartment closeouts behind the front panels. This was unacceptable to NASA and closeouts would be required.

- North American definition and review of all spacecraft materials applications were in progress, but Borman reported the progress was too slow to date and that a plan for expediting was under consideration.

- Fire extinguisher interfaces had not yet been identified. A meeting was planned during the next week to resolve the problem.

- NASA reaffirmed to North American the intention that DITMCO (an inspection process) of the completed installed harness be performed as late as possible and that harness protection be reinstalled immediately after DITMCO. Connectors which could not be DITMCOed must be reviewed with NASA, connector by connector.

- NASA reaffirmed that a crew compartment fit and function test was required on each spacecraft at Downey.

- Two meetings had been held on the Downey spacecraft 101 test and checkout. Definition of requirements was progressing rapidly and was expected to be completed and signed off by May 5. A schedule would be prepared for distribution on May 9, for the preparation, review and final approval of the operational checkout procedures necessary for the approved test requirement. The launch site test plan for spacecraft 101 would be discussed in a meeting at Downey May 9, and this meeting would be followed by a discussion of spacecraft 2TV-1 Downey test requirements as related to the Houston tests for the spacecraft 101 mission.

- The Test Group of the Task Team planned to work closely with the Checkout Working Group and would be represented in its next meeting in Downey on May 11.

- Rework resulting from the wiring inspection of spacecraft 101 was not proceeding as rapidly as desired; however, Borman reported that more efficient procedures were being prepared and would be carried out as soon as possible.

- The Apollo spacecraft quality requirements were being reviewed and the North American Quality Plan would be checked against these requirements in detail.

Borman reported on plans and schedules:

- A documentation center was being established to provide configuration documentation to the North American and NASA teams. A master change status board would be maintained in the NASA Task Team Office, and Block II specifications would be updated to provide the predesign baseline.

- North American had released Master Development Schedule-10 ahead of its May 12 schedule, and detailed engineering, manufacturing, and Apollo test operation schedules were being prepared.

Critical open items were:

- TV monitor requirements and interfaces,

- flashing beacon mechanization and requirements,

- material for the lithium hydroxide canister,

- emergency oxygen mask mechanization,

- water chlorination mechanization,

- rapid repressurization-mechanization or surge tank, and

- cabin recirculation valve requirement.

Anthony W. Wardell of the MSC Flight Safety Analysis Office wrote Apollo Manager Low that "the May 10 inspection further substantiates my previous recommendation to replace, rather than rework, the (spacecraft 101 wiring) harness.

In addition to the visual evidence of wire damage noted, a book containing about 100 outstanding wire damage MRB (Material Review Board) actions was noted on a work table near the spacecraft." He did, however, list seven recommended suggestions to be followed in the event the harnesses were reworked rather than replaced. The suggestions were passed on to CSM Manager Kenneth S. Kleinknecht by Low in a memorandum on May 13. Low requested that the suggestions be passed to North American Aviation as soon as possible, with additional suggestions from MSC Quality Control Chief Jack A. Jones, who had also inspected the harness.

The NASA Block II CSM Redefinition Task Team was augmented by the assignment of Gordon J. Stoops as Group Leader-Program Control, with the following functions:

• Liaison with North American Aviation Program Control and Contracts to expedite updating of the contract change authorizations and the issuance of timely program technical direction.
• Liaison with the ASPO CSM project Engineering and Checkout Division and CSM Contract Engineering Branch at MSC to expedite contract change authorizations and ensure timely program technical direction.

Prime and backup crews for Apollo 7 (spacecraft 101) were named, with the assignments effective immediately. The prime crew for the engineering-test-flight mission was to consist of Walter M. Schirra, Jr., commander; Donn F. Eisele, CM pilot; and R. Walter Cunningham, LM pilot. The backup crew was Thomas P. Stafford, commander; John W. Young, CM pilot; and Eugene A. Cernan, LM pilot. Names had been reported to the Senate Committee on Aeronautical and Space Sciences on 9 May.

A Block II spacecraft vibration program was begun to provide confidence in CSM integrity and qualify the hardware interconnecting the subsystems within the spacecraft. A test at MSC was to simulate the vibration environment of max-q flight conditions. The test article was to be a Block II CSM. A spacecraft-LM adapter, an instrumentation unit, and an S-IVB stage forward area simulation would also be used.

MSC notified NASA Hq. that - with the changes defined for the Block II spacecraft following the January 27 Apollo 204 fire and with CSM delivery schedules now reestablished - it was necessary to complete a contract for three additional CSMs requested in 1966. North American Aviation had responded September 15, 1966, to MSC's February 28 request for a proposal, but action on a contract had been suspended because of the AS-204 accident. NASA Hq. on June 27, 1967, authorized MSC to proceed.

NASA Headquarters and MSC officials attended a review of the CSM at North American Aviation in Downey.

Following the North American briefing, the group visited the wire-harness layout and assembly areas. NASA Associate Administrator for Manned Space Flight George E. Mueller, with Anthony W. Wardell and Jack A. Jones of MSC, inspected the wiring in spacecraft 101 and 2TV-1 in detail.

Mueller stressed the importance of improving spacecraft delivery schedules, with particular emphasis on spacecraft 020 and the second and third manned spacecraft, working up to two-month delivery intervals. He was concerned about the five- to six-week spacecraft 020 hatch delay and stated that Apollo Program Director Samuel C. Phillips must approve the proposed change. North American pointed out that it was using the resources of the corporation toward the two-month delivery schedule, and that a modification task-team approach would be used as long as it was effective in improving schedules. Tiger teams of engineering, quality, manufacturing, and materials personnel were working on wiring and plumbing in spacecraft 101. CSM Manager Kenneth S. Kleinknecht reviewed the Block II Redefinition Task Team effort for Mueller and he indicated that Phillips had considered an industry tiger team to assist in the overall spacecraft effort.

W. R. Downs, Special Assistant for Advanced Systems, MSC Structures and Mechanics Division, discovered that bare or defectively insulated silver-covered copper wires exposed to glycol/water solutions would ignite spontaneously and burn in oxygen. Copper wire or nickel-covered copper wire under identical conditions did not ignite. The laboratory results were confirmed in work at the Illinois Institute of Technology. In a June 13 memorandum, the Chief of the Structures and Mechanics Division recommended that if additional testing verified that nickel-coated wires were free of the hazard, consideration should be given to an in-line substitution of nickel-coated wires for silver-coated wires in the LM. It was understood that the Block II CSM already had nickel-coated wires. In a June 20 memo to the ASPO Manager, the Director of Engineering and Development pointed out that silver-plated pins and sockets in connectors would offer the same hazards. He added that Downs had also identified a chelating agent that would capture the silver ion and apparently prevent the reaction chain. In a July 24 memorandum, ASPO Manager George Low said that, in view of recent spills of ethylene glycol and water mixtures, spacecraft contractors North American Aviation and Grumman Aircraft Engineering had been directed to begin actions immediately to ensure that a fire hazard did not exist for the next manned spacecraft. Actions were to include identification of the location of silver or silver-covered wires and pins and of glycol spills.

NASA Office of Manned Space Flight had redefined the Apollo Block II manned mission flight plan, ASPO informed the MSC Director of Science and Applications. The first manned flight plan called for

1. an open-ended mission up to 10 days,
2. sufficient instrumentation,
3. no extravehicular activity,
4. a CSM rendezvous with the S-IVB stage, and
5. no experiments that required spacecraft integration.

At a NASA and North American Aviation management meeting, North American was directed to proceed with development of larger drogue parachutes and staged main chute disreefing, using 5- and 8-second reefing-line cutters.

Later analysis of the system and the proposed modifications still indicated only a marginal capability to offer adequate factors of safety, and North American was directed to use 6- and 10-second reefing-line cutters. In a letter to Headquarters, MSC Director Robert R. Gilruth mentioned that a review of these modifications had been covered at the September Manned Space Flight Management Council and, since no objections were voiced at that time, MSC assumed concurrence with the changes and would implement modifications for spacecraft 101 and subsequent Block II spacecraft.

The purpose of spacecraft 105 testing was to establish transition relations between the primary and secondary structure that supported systems' interconnecting hardware (wiring, tubing and associated valves, filters, regulators, etc.) and demonstrate structural integrity of the Block II CSM when subjected to qualification vibration environment, with special emphasis on interconnecting hardware. The test vehicle was being configured with complete basic Block II wiring harness and fluid systems. The vehicle would be checked out before and after each phase of testing to verify wiring harness impedance and continuity and fluid systems pressure integrity. The fluid systems would be at operating pressure during the testing.

Plans were to armor-plate 102 out of 167 solder joints inside the CM of spacecraft 101, ASPO Manager George M. Low informed Maxime A. Faget, MSC's Director of Engineering and Development.

Of the remaining 65 joints, 53 would be accessible for armor-plating and x-raying, while the other 12 would not. Low said: "As joints become less accessible, the excess solder removal process, the joint-cleaning process, and the application of the armor-plating become more difficult. Also, in many places, the standard armor-plating sleeve does not fit, and a shorter or cutaway sleeve is required. I have therefore reached the conclusion that, at some point, the armor-plating process may become detrimental. . . . You should know that Mr. (Joseph N.) Kotanchik disagrees with this position. Joe believes that any joint in the spacecraft could be under stress and therefore is subject to creep. The only solution . . . according to Joe, is to armor-plate all joints. . . ." Low added that joints that are accessible from outside the CSM would also be armor-plated and that future spacecraft would include additional armorplating. He said, "My expectation is that all solder joints will be armor-plated in the lunar configuration. . . ."

The Apollo Program Director requested MSC to assign the following experiments to AS-205, spacecraft 101: M006 - Bone Demineralization, M011 - Cytogenic Blood Studies, M023 - Lower Body Negative Pressure, S005 - Synoptic Terrain Photography, and S006 - Synoptic Weather Photography.

Experiment D008, Radiation in Spacecraft, would be included in the above list at the option of ASPO. On July 21 ASPO Manager George M. Low informed CSM Manager Kenneth S. Kleinknecht that he was approving reinstatement of Experiments S005 and S006 on AS-205. On the same date Low informed the Apollo Program Director that S005 and S006 would be carried on AS-205. He proposed that experiments M006, M011, and M023, which required pre- and postflight operations with the crew, be classified not as experiments but as part of the normal pre- and postflight medical evaluation. Experiment D008 was deleted from AS-205 and all other inflight experiments previously assigned had been deleted from the spacecraft. MSC's Director of Medical Research and Operations Charles A. Berry and Director of Space Science and Applications Wilmot N. Hess concurred with Low's decision.

A CSM shipment schedule, to be used for planning throughout the Apollo program and as a basis for contract negotiations with North American Aviation, was issued by NASA Hq. The schedule covered CSM 101 through CSM 115, CSM 105R, and CSM 020 and the period September 29, 1967, through November 17, 1969.

ASPO announced that a detailed review of the Block II CSM would be held to gain a better understanding of the hardware. ASPO Manager George M. Low pointed out that it had been customary in the Gemini and Apollo Programs to conduct Design Certification Reviews (DCRs) before manned flight of the "first of a kind" vehicle. He added that the detailed review should address itself to design and analysis, test history and evaluation of test results, and the understanding of operational procedures for each element in the CSM. To ensure the most thorough review, MSC divisions would conduct preliminary reviews. The division chiefs would then present their findings to the directorates, the ASPO management, and the MSC Director.

The NASA task team for CSM Block II redefinition, established on April 27, was phased out. During its duration the task team provided timely response and direction in the areas of detail design, overall quality and reliability, test and checkout, baseline specifications, and schedules. With the phaseout of the team, Apollo Spacecraft Program Office policies and procedures would be carried out by the ASPO resident manager. A single informal point of contact was also established between MSC and North American for engineering and design items.

ASPO Manager George M. Low, in a letter to Dale D. Myers of North American Aviation, expressed disappointment that both spacecraft 2TV-1 and 101 had slipped approximately six weeks.

He also expressed astonishment that managers, who were supposedly using a planning system, did not understand the meaning of the charts they were using. Low suggested more attention to detail by managers, a better tracking system for shortages, assignment of responsible individuals to areas where special efforts were needed; and a mechanized system for tracking such things as work needing to be done and shortages.

Key dates in the spacecraft 101 schedule were agreed to during a meeting of Samuel C. Phillips, Robert R. Gilruth, George M. Low, and Kenneth S. Kleinknecht with North American management: inspection of wiring, October 7, 1967; completion of manufacturing, December 15, 1967; delivery, March 15, 1968. In addition, several decisions were reached concerning certain systems of spacecraft 101. Among these, it was agreed that the entry monitor system would not be checked out on spacecraft 101.

Apollo Program Director Samuel C. Phillips, NASA Hq., reaffirmed that the following was the best course of action to follow with LM-2 and LM-3 .

"Decide now to configure LM-2 for its unmanned contingency mission and reassign LM-3 to join with CSM 103 for a manned CSM-LM mission. In the event the LM-2 unmanned contingency mission is not required, LM-2 could be reworked to manned configuration and cycled back into the GAEC (Grumman) line for later delivery. On this basis, LM-2 could be delivered in unmanned configuration in late January 1968, or immediately after the Apollo 5 flight, and could be flown on AS-206 about 3½ months after delivery; i.e., in May 1968. The outlook for LM-3 indicates an April 1968 delivery which appears to be compatible with the expected delivery date of CSM 103."

ASPO Manager George Low submitted a memorandum for the record on the September 29 decision not to check out the spacecraft 101 entry monitor system (EMS).

He said: ". . . it has come to my attention that this decision had been based on incomplete information. Because the EMS incorporates both the Delta V counter and the .05 g indication on Block II spacecraft, this system is required for all missions, including 101. . . . "I verbally directed North American on October 10, 1967, that this system will be checked out on Spacecraft 101."

NASA Hq. informed MSC that NASA Deputy Administrator Robert C. Seamans, Jr., had approved the project approval document authorizing four additional CSMs beyond No. 115A. MSC was requested to proceed with all necessary procurement actions required to maintain production capability in support of projected schedules for these items.

ASPO Manager George Low, in a memorandum to CSM Manager Kenneth Kleinknecht, remarked that he had "just read Dale Myers' letter to you . . . on the subject of Northrop Ventura performance. In addition I have . . . read a letter from Dick Horner to me in response to my letter . . . of September 29, 1967.

Both of these letters have the same general tone: they indicate that problems did exist in the past, but that all problems have now been resolved. . . . I am still . . . uneasy about the Northrop Ventura situation. I would, therefore, recommend that you might personally want to visit the Northrop Ventura facilities so that you can, at first hand, inspect their plant, review their program and talk to their people. You might want to ask Eberhard Rees, Scott Simpkinson and Sam Beddingfield to join you on such a visit. I would hope . . . you would see fit to make this visit in the very near future so that any corrective actions that you might identify can be taken before the Spacecraft 101 parachutes are packed."

Walter J. Kapryan of the MSC Resident ASPO at KSC told the KSC Apollo Program Manager that one of the primary test objectives of the SM-102 static-fire test was to determine system deterioration caused by the static-fire sequence and exposure to residual hypergolics trapped in the system during subsequent prelaunch operations.

He said it was imperative that the objective be met before the planned static-firing test of the SM-101. MSC requested that every effort be made to make the SM-102 test as soon as possible to ensure a representative time for subsequent storage and that a contractor tear-down inspection could be made to assess the advisability of static-firing the flight spacecraft. A firing date of January 15, 1968, would accomplish those objectives.

The phase I customer acceptance readiness review (CARR) of CM 101 was held at North American Rockwell in Downey, Calif.

MSC's CSM Manager Kenneth S. Kleinknecht chaired the meeting, and SC 101 Manager John Healey represented North American. The review was the first of a three-phase CARR system initiated by North American. A total of 44 customer acceptance review item dispositions (CARIDs) were presented to the board and 13 were closed. The spacecraft was accepted for turnover to Apollo Test Operations pending submission of data to close the remainder. The majority of open CARIDs were for completing documentation for engineering orders, operation checkout procedures, and photography, with both North American and MSC having action item for closing out CARIDs. Five CARIDs made reference to flammability of material. The most significant item was the installation of 27.4 meters of coaxial cable in the spacecraft that did not meet flammability guidelines.

As a part of the managers' technical status review, Dale Myers of North American Rockwell presented his analysis of fixes for the coax cable in spacecraft 103 and subsequent spacecraft.

The North American recommendation was:

- For spacecraft 103, 104, and 106 - remove all coax and wrap with aluminum tape using a 75- to 90-percent overlap. Re-install wrapped coax with additional teflon overwrap in areas where chafing might occur. This wrapping would increase spacecraft weight by 0.9 kilograms. Schedule impact was estimated at five days for spacecraft 103 and 104 and one day for spacecraft 106.

- For spacecraft 107 and subsequent spacecraft - install new coax cable that would meet nonmetallic-materials guidelines. There would be no schedule impact.

According to MSC's CSM Manager Kenneth S. Kleinknecht, the North American recommendation was justified for the following reasons:

- All coax would be installed before the inspection process.

- Spacecraft 106 was ready for electrical harness closeout; fabrication of new cables, with guideline material, would delay closeout by about three weeks.

- The new cable to be used in spacecraft 107 was already used on the spacecraft upper deck, but had not been subjected to corrosive contaminants, oxygen, and humidity qualification. This qualification would be completed in line and before cable installation.

- Although connectors used with coax on the upper deck were compatible with black boxes in the spacecraft and were supposedly available, there were not enough in stock to support the fabrication of new cables for spacecraft 103, 104, and 106.

- Testing at North American and MSC supported the conclusion that wrapping with aluminum tape would preclude propagation of burning if ignition of the coax should occur.

Kleinknecht decided, with concurrence of Maxime A. Faget and Jerry W. Craig, to accept the proposal and Myers was authorized to proceed, subject to concurrence by Program Director Samuel C. Phillips and Program Manager George M. Low. Kleinknecht received oral concurrence from Low and Phillips on December 20; then, in confirming the decision with Myers, he requested that North American develop a schedule recovery plan to negate the impact of the coax fix on spacecraft 103, 104, and 106.

Apollo Program Director Samuel C. Phillips told ASPO Manager George M. Low that a review had begun on the "Apollo Spacecraft Weight and Mission Performance Definition" report dated December 12 and that his letter indicated approval of certain changes either requested or implied by the report. Phillips added that his letter identified a second group of pending changes for which insufficient information was available. He stressed his serious concern over the problem of spacecraft weight growth and said weight must be limited to the basic 45,359-kilogram launch vehicle capability. "According to the progression established in your report, CM's 116 through 119 could exceed the parachute hand-weight capability. I would like to establish a single set of controlled basic weights for the production vehicles. For product improvement changes a good rule is a pound deleted for every pound added. For approved changes to the basic configuration, it is the responsibility of NASA to understand the weight and performance implication of the change and to establish appropriate new control values. . . ."

CSM Manager Kenneth S. Kleinknecht wrote his counterpart at North American Rockwell, Dale D. Myers, to express concern about NR's seeming inability to implement configuration control of flight hardware and ground support equipment.

Some progress had been made recently, Kleinknecht observed, but many steps still had to be taken to achieve effective configuration management on the CSM. The MSC chief pointed especially to North American's inability to ensure that final hardware matched that set forth in engineering documents, a weakness inherent in the separate functions of manufacturing: planning, fabrication, assembly and rework. MSC recommended a check procedure of comparing part numbers of installed equipment to the "as designed" parts list. "In short," Kleinknecht concluded, "I think that we should tolerate no further delay in establishing a simple 'as built' versus 'as designed' checking function, beginning with and including the first manned spacecraft."

North American began a more nearly complete engineering order accountability system, which provided an acceptable method of verifying the "as designed" to the "as built" configuration of each spacecraft. This system was planned to be applicable by the Flight Readiness Review on spacecraft 104 and on subsequent spacecraft at earlier points.

ASPO Manager George M. Low outlined for the NASA Apollo Program Director MSC plans to static-fire the service propulsion system (SPS) as a complete unit.

Houston officials maintained that at least one firing of such a complete system was necessary to prove the adequacy of all SPS manufacturing, assembly, and testing. However, because of several potential adverse effects that might accrue to testing the first such available system (that for the 101 SM), MSC proposed to test-fire the 102 unit and interpret those results - including any possible damage to the SM structure itself - before making a final decision on whether to proceed with a ground firing of the actual flight hardware before flight.

A meeting was held at MSC to determine necessary action concerning recent contamination of CM 103's potable water, oxygen, and water-glycol lines.

North American Rockwell proposed that all 103 aluminum lines in the potable water and oxygen systems (approximately 72 segments) be replaced; and proposed to follow a chemical flushing procedure for the water-glycol lines to remove the aluminum oxide and copper contamination. North American estimated that these actions would cause a 15-17 day serial impact. Removal and replacement of all lines would result in an estimated impact of 45 days. A decision was made to concur with the North American recommendation and on January 19 Kenneth S. Kleinknecht, MSC, informed Dale D. Myers, North American, of the concurrence and authorized him to proceed immediately. In addition, Kleinknecht appointed a Special Task Team for Spacecraft 103 Contamination Control to ensure timely review of all contractor activities associated with removal of the contamination from the spacecraft environmental control system coolant system. Members of the team were: Wilbur H. Gray, Chairman; A. M. Worden, W. R. Downs, Jack Cohen, A. W. Joslyn, R. E. Smylie, R. P. Burt, and W. H. Taylor.

On February 20 Myers notified Kleinknecht of initiation of the potable water line changes and setting up of a monitor water-glycol system that would duplicate CSM 103 operations during the balance of checkout and would be examined for corrosion damage just before Flight Readiness Review.

The Special Task Team for CSM 103, appointed January 18, submitted a progress report of activities during daily sessions held January 22 through 25.

North American Rockwell and NASA had reached agreements on:

- Cleaning and flushing of water management and oxygen systems. Since all aluminum lines except for three were replaced on CM 103 with new lines the resolution for cleaning and flushing these systems was quickly accomplished.

- Cleaning and flushing of water glycol system.

- Pressure integrity of the water glycol system would be confirmed by a hydrostatic check to 248 newtons per square centimeter (360 pounds per square inch). Leak integrity would be confirmed by subsequent checks with helium at 41 newtons per sq cm (60 psi).

- A resolution was obtained on the chemistry of the various cleaning and flushing fluids to be used on CM 103.

- Agreement was reached on verification of cleaning and flushing all flow paths.

The events leading to the situation on CSM 103 were reviewed in sufficient detail to make visible the errors in the discipline governing the flushing carts. RASPO Manager Wilbur H. Gray stated that it was the RASPO responsibility to ensure the upgrading and control of all such equipment which interfaced with the spacecraft. The team would convene again January 30 to review reports and continue with other activities required to ensure adequacy of the CSM 103 plumbing system.

In response to action required by the CSM 2TV-2 and CSM 101 Wire Board in October 1967, Dale D. Myers, CSM Program Manager at North American Rockwell, submitted to MSC results of a wire improvement study for the umbilical feedthrough area for the lower equipment bay.

Myers stated that substantial improvements in wiring appearance in the lower equipment bay had been made even before the Wire Board's ordered study and that further improvements of any significant nature could not be made without major structural changes (which would be intolerable from the standpoint of mission schedules). Thus, Myers recommended against further changes in wiring in the lower equipment bay. Further, as installation procedures and wire protective measures had improved, the occurrence of wiring damage had been progressively reduced. This same rationale, Myers affirmed, applied to other harness areas inside the spacecraft. (This study by North American completed action items generated at the Wire Board meeting.)

MSC had decided not to static-fire the service modules of Block II spacecraft before flight (specifically, spacecraft 101), ASPO advised NASA Hq.

The decision was based on successful completion of the spacecraft 102 static firing, evaluation of the test history on the service propulsion system, and a review by a joint MSC-MSFC team that came out flatly against any such static firings at KSC and acceded to such tests at White Sands only under Houston's strict authority. During subsequent discussions in Houston (notably a February 19 meeting with the MSFC contingent), program planners rejected such firings at White Sands because the additional transportation and handling might degrade reliability of the hardware - exactly the opposite of what was being sought.

Design Certification Reviews of CSM 101 and LM-3 were held at MSC. Significant program-level agreements reached included validation of a 60-percent-oxygen and 40-percent-nitrogen cabin atmosphere during launch; reaffirmation of the February 6 Management Council decision that a second unmanned LM flight was not required; and the conclusion that, in light of successful static firing of the 102 service propulsion system and subsequent analysis, a static-firing of the 101 system was not required.

ASPO Manager George Low emphatically rejected North American Rockwell's suggestion of added spacecraft delivery delays.

Responding to a February letter from North American CSM Program Manager Dale D. Myers - suggesting further slips in delivery of 2TV-1 and spacecraft 101, 103, and 104 - Low reminded Myers that at the close of the Configuration Control Board meeting on February 23 he had cited a mid-April target for delivery of CSM 101. Since that time, Low said, KSC had been actively preparing for an early summer launch based on that mid-April delivery, and circumstances therefore made that date most important. Moreover, North American must deliver CSM 103 by the end of June 1968 in order to ensure meeting Apollo's end-of-the-decade goal. He reminded Myers that he had pursued this point on several occasions with him and with William Bergen. They both had told Low that they had found ways to deliver 103 within that time frame, and Low now suggested that this target date be made a firm commitment in the official Apollo schedules. At the earliest possible date, Low concluded, MSC and North American must establish firm contractual baselines for delivery schedules. Until then present delivery dates remained valid. He admitted that some schedule slips had resulted from NASA-dictated changes and that the schedules should be adjusted accordingly. The remaining delays, however, Low attributed directly to the company's inability to meet projected commitments. The contract was changed to call for an April 1968 delivery for CSM 101 and a June 1968 delivery for CSM 103.

A TV camera would be carried in CM 101 on the first manned Apollo flight, Apollo Program Director Samuel C. Phillips, wrote the ASPO Manager (confirming their discussions).

Incorporation and use of the camera in CM 101 would conform to the following ground rules:

- The TV camera and associated hardware would be installed at KSC with no impact on launch schedule;

- the camera would be stowed during the launch phase;

- a mounting bracket for the camera would be provided in the CM to permit simultaneous viewing of all three couch assemblies, for use in monitoring prelaunch hazardous tests and in flight;

- the camera could be hand-held for viewing outside the CM during flight; and

- use of the camera would not be specified on the astronaut's flight planning timeline of essential activities but would be incorporated in the mission as time and opportunity would permit.

A number of decisions were made at the completion of a parachute review at Northrop-Ventura.

- The spacecraft 101 parachute system would be flown without further changes.

- A higher drogue-mortar muzzle velocity would be planned, with a possible effectivity for spacecraft 103. North American Rockwell would determine what ground tests were required, when flight hardware would be ready, and what additional qualification tests were needed.

- Proposed Northrop-Ventura changes in drogue riser size and riser length would be considered only for design and ground testing activities.

- North American would propose to NASA an augmented confidence-level test program.

- For follow-on work, NASA would contract directly with Northrop- Ventura only for analytical work (all test effort would be contracted through North American).

- Northrop-Ventura would examine the swagged fittings to determine whether a possible stress corrosion problem might exist.

- Northrop-Ventura would obtain sufficient documentary photography during parachute packing for manned flight vehicles to provide subsequent quality examination.

- Northrop-Ventura would prepare a package depicting the flight and design envelope of the parachutes, together with tests already achieved and tests planned.

- Finn direction to Northrop-Ventura in all applicable areas would be provided by North American.

Apollo Special Task Team Director Eberhard Rees wrote Dale D. Myers at North American Rockwell: "As you are well aware, many manhours have been spent investigating and discussing the radially cracked insulation on wire supplied by Haveg Industries.

On March 27, 1968, NR (North American Rockwell) made a presentation on this problem and reported the action taken to correct the problem and to prevent defective wire from being used. . . . It was disturbing to me to learn that with all the additional actions. . . cracked insulation again was found, this time during the manufacture of harnesses for C/M 110, 111, 112 and S/M 111. This raises the question as to whether the total problem has really been identified and whether or not sufficient corrective action has been taken. . . ." Rees then requested a reply to 10 questions he submitted as to reasons for the problem and possible actions that might be taken.

Two major requirements existed for further service propulsion system (SPS) testing at the Arnold Engineering Development Center (AEDC), ASPO Manager George M. Low advised Apollo Program Director Samuel C. Phillips.

First, the LM docking structure was marginal at peak SPS start transient. While evaluation of the redesigned docking mechanism was under way, final hardware design and production could not be completed until positive identification of the start transient was made through the AEDC test series. Secondly, a modified engine valve had been incorporated into the SPS for CSM 101, which thus necessitated further certification testing before flight (comprising sea-level static firings, simulated altitude firings, and component endurance tests). Low emphasized the need to complete this testing as soon as possible, to isolate any potential problems.

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.

ASPO Manager George M. Low explained to the Apollo Program Director the underlying causes of slips in CSM and LM delivery dates since establishment of contract dates during the fall of 1967. The general excuse, Low said, was that slips were the result of NASA-directed hardware changes. "This excuse is not valid." He recounted how NASA-imposed changes had been under strict control and only essential changes had been approved by the MSC Level II Configuration Control Board (CCB).

For early spacecraft (CSM 101 and 103 and LM-3), the CCB had agreed some six months earlier that only flight safety changes woul be approved. To achieve firm understandings with the two prime spacecraft contractors regarding the responsibilities for schedule slips, Low had asked MSC procurement expert Dave W. Lang to negotiate new contract delivery dates based on changes since the last round of negotiations. These negotiations with North American Rockwell were now completed. (Talks at Grumman had not yet started.) Despite a leniency in the negotiations on early spacecraft, Low said, results clearly indicated that most schedule delays were attributable to North American and not to NASA. On 2TV-1, for example, delivered two months late, analysis proved that less than three weeks of this delay derived from customer-dictated changes. The situation for CSM 101, though not yet delivered, was comparable. Moreover, a similar situation existed within the LM program: LM-3 would be delivered some five weeks behind the contract date, with only two of those weeks caused by NASA changes. Despite this attempt to set the record straight regarding schedule slippages, Low stressed that he did not wish to be over critical of the contractors' performance. Because schedules over the past year had been based on three-shift, seven-day-per-week operation, little or no time existed for troubleshooting and "make work', changes that inevitably cropped up during checkout activities.

ASPO Manager George Low advised Apollo program officials at KSC that, to collect adequate data for evaluating any potential toxicological hazard inside the spacecraft, collection of gas samples of the cabin atmosphere must be made for 12 hours during the unmanned altitude chamber test with all systems operating. Low asked that this requirement be included in the spacecraft test procedures.

(Purpose of a total CSM 101 and LM-3 toxicological evaluation was to verify that no toxic contaminants were given off by the nonmetallic materials used in the crew compartments.)

ASPO Manager George M. Low met with Christopher C. Kraft, Jr., and Donald K. Slayton, Directors of MSC Flight and Flight Crew Operations, and several members of their staffs (including astronaut Walter M. Schirra, Jr.) to discuss using the flight combustion stability monitor (FCSM) on the Apollo 7 flight.

(The FCSM was a safety device to shut down the service propulsion system (SPS) automatically in the event of rough combustion or instability.) At the insistence of the Propulsion and Power Division, they agreed to use the FCSM for all SPS burns on Apollo 7. On all "noncritical" burns, two attempts to start the engine would be made with the FCSM active. Should the stability monitor shut down the engine on both those attempts, a detailed review of the situation would be made before again attempting to start the engine. On "critical" burns (i.e., the abort-to-orbit and reentry burns), should the FCSM halt the burn the SPS engine would be restarted immediately with the FCSM inactive on the assumption that the shutdown was caused either by an FCSM malfunction or by an engine instability that would not reoccur on the next start.

Low, Kraft, and the others unanimously wanted to eliminate the FCSM before a lunar mission, because on this mission lunar orbit and transearth insertion burns were highly critical and inadvertent shutdowns would cause major trajectory perturbations. Representatives from the Propulsion and Power Division (PPD) contended that, because of the relatively small number of bomb tests carried out on the Block II SPS engine, flight-testing of the engine before the lunar mission would be inadequate to demonstrate engine stability under all conditions. Low therefore asked Engineering and Development Director Maxime A. Faget and PPD Chief Joseph G. Thibodaux, Jr., to plan a ground test program that would give sufficient confidence in the SPS engine to eliminate the FCSM before undertaking lunar missions.

Dale D. Myers, Apollo CSM Program Manager at North American Rockwell, advised MSC officials of his company's investigation of two pilot-chute riser failures during recent drop tests of the Block II earth-landing system. Should there be any imperfections in either hardware or assembly techniques, Myers explained, the Block II pilot chute and riser system could be a marginal-strength item. Investigations had determined that early manufacturing processes had allowed a differential length between the two plies of nylon webbing in the pilot-chute riser which caused unequal load distribution between the two plies and low total riser strength. Because of the earlier test failures, Myers said, the pilot chute riser had been redesigned. The two-ply nylon webbing had been replaced by continuous suspension lines (i.e., 12 nylon cords) and the 5.5-millimeter-diameter cable was changed to 6.3-millimeter cable. He then cited a series of recent tests that verified the redesigned pilot-chute riser's strength to meet deployment under worst-case operational conditions.

NASA and contractor technicians successfully conducted the final parachute drop test to qualify the Apollo CSM earth-landing system. The Block II ELS thus was considered ready for manned flight after 12 Block I, 4 Block II, and 7 increased-capability Block II Qualification Tests - that had followed 77 Block I, 6 Block II, and 25 increased-capability Block II Development Drop Tests.

The Apollo Design Certification Review (DCR) Board met in Houston to examine CSM 101 and the Block II CSM for proof of design and development maturity and to certify the designs for flightworthiness and manned flight safety.

(Three earlier reviews directly supported this penultimate scrutiny of the vehicle's development: the CSM 101 Design Certification Review March 6-7, the Block II environmental control system and spacesuit DCR May 8, and the DCR covering the CM land and water impact test program June 6.) The board concluded that design certification on CSM 101 was complete. Action and open items were subsequently forwarded to the Centers for resolution, to be closed before the Apollo 7 Flight Readiness Review.

In the continuing effort to reduce costs while still maintaining a balanced and viable program, ASPO Manager George M. Low recommended to NASA Hq. that CSM 102 be deleted from the manned flight program. He estimated total savings at $25.5 million (excluding cost of refurbishment after the current ground test program). In addition, he said, during the static structural test program at North American Rockwell, CSM 102 would be subjected to loads that would compromise structural integrity of the vehicle for manned flight.

On August 7, Low asked MSC's Director of Flight Operations Christopher C. Kraft, Jr., to look into the feasibility of a lunar orbit mission for Apollo 8 without carrying the LM. A mission with the LM looked as if it might slip until February or March 1969. The following day Low traveled to KSC for an AS-503 review, and from the work schedule it looked like a January 1969 launch.

Events and the situation during June and July had indicated to Low that the only way for the "in this decade" goal to be attained was to launch the Saturn 503/CSM 103 LM-3 mission in 1968. During June and July the projected launch slipped from November to December, with no assurance of a December launch. Later, Low recalled "the possibility of a circumlunar or lunar orbit mission during 1968, using AS-503 and CSM 103 first occurred to me as a contingency mission."

During the period of July 20-August 5, pogo problems that had arisen on Apollo 6 seemed headed toward resolution; work on the CSM slowed, but progress was satisfactory; delivery was scheduled at KSC during the second week in August and the spacecraft was exceptionally clean. The LM still required a lot of work and chances were slim for a 1968 launch.

NASA Associate Administrator for Manned Space Flight George E. Mueller reported to his superiors that launch preparations for the Apollo 7 mission were running ahead of schedule. Spacecraft 101 had been erected and mated with the launch vehicle on August 9.

Integrated systems testing had begun on August 15. Preparation for the next mission, Apollo 8, were not proceeding as well. Checkout of the launch vehicle and CSM 103 were on schedule, but work on LM-3 was some seven days behind schedule. Though LM-3's problems were under intensive investigation, they were directly holding up the simulated mission run and transfer to the altitude test chamber.

NASA Resident ASPO Manager Wilbur H. Gray at Downey told Dale D. Myers, North American Rockwell CSM Manager, that NR quality coverage of spacecraft testing no longer provided NASA with confidence in test results and that NASA Quality Control would return to monitoring test activities in and from the ACE (acceptance checkout equipment) control room. Gray charged that North American had progressively backed away from contractually agreed steps of the November 30, 1967, Quality Program Plan, and that these actions had affected test readiness, testing, and trouble shooting to the point that test acceptance could not be accepted with any reasonable assurance. Gray said that - unless North American responded by immediate reinstatement of the procedures which, as a minimum, were those that worked satisfactorily on CSMs 103 and 104 - NASA formal acceptance of operational checkout procedures would be discontinued and contractual action initiated. An annotation to George Low from Kenneth S. Kleinknecht, MSC's CSM Manager, indicated the letter had been written with the concurrence and at the suggestion of Kleinknecht.

Myers replied: "I regret that NASA feels any lack of confidence in current test results. . . . For the past year, there has been a constant improvement program carried out in Test Quality Assurance to (1) perform quality evaluation and acceptance of test results in real time and (2) upgrade the test discipline to be consistent with good quality practice. I believe that this improvement program has been effective and is evidenced by the current efficiency of test and expedient manner in which test paper work is being closed out. While there is naturally some cost benefit experienced from the successful improvements, cost never has been placed as a criteria above quality. . . .

"Again, I want to emphasize that the CSM Program has not nor will not intentionally place cost ahead of quality. . . . The procedures which worked satisfactorily on CSM 103 and 104 are being improved to provide better test discipline and more effective Quality Assurance coverage. Test progress on CSM 106 to date indicates a greater test effectiveness and a greater confidence in test results than any previous CSM's."

Myers, North American Rockwell CSM Manager, that NR quality coverage of spacecraft testing no longer provided NASA with confidence in test results and Gray charged that North American had progressively backed away from contractually agreed steps of the November 30, 1967, Quality Program Plan, and that these actions had affected test readiness, testing, and trouble shooting to the point that test acceptance could not be accepted with any reasonable assurance. Gray said that - unless North American responded by immediate reinstatement of the procedures which, as a minimum, were those that worked satisfactorily on CSMs 103 and 104 - NASA formal acceptance of operational checkout procedures would be discontinued and contractual action initiated. An annotation to George Low from Kenneth S. Kleinknecht, MSC's CSM Manager, indicated the letter had been written with the concurrence and at the suggestion of Kleinknecht.

Myers replied: "I regret that NASA feels any lack of confidence in current test results. . . . For the past year, there has been a constant improvement program carried out in Test Quality Assurance to (1) perform quality evaluation and acceptance of test results in real time and (2) upgrade the test discipline to be consistent with good quality practice. I believe that this improvement program has been effective and is evidenced by the current efficiency of test and expedient manner in which test paper work is being closed out. While there is naturally some cost benefit experienced from the successful improvements, cost never has been placed as a criteria above quality. . . .

"Again, I want to emphasize that the CSM Program has not nor will not intentionally place cost ahead of quality. . . . The procedures which worked satisfactorily on CSM 103 and 104 are being improved to provide better test discipline and more effective Quality Assurance coverage. Test progress on CSM 106 to date indicates a greater test effectiveness and a greater confidence in test results than any previous CSM's."

MSC Director Robert R. Gilruth sent Eberhard F. M. Rees, MSFC Deputy Director, his "personal commendation" and appreciation for Rees's leadership of the Apollo Special Task Team and its efforts to bring the CSM program out of the difficult period early in 1967. The work of Rees and his group, said Gilruth, had made an outstanding contribution to the Apollo program and had given NASA management "a significantly higher level of technical confidence" that the Block II spacecraft could safely perform its mission. In addition, Gilruth noted, Rees's "diplomacy in interfacing with North American management also created a much better NASA-contractor relationship and mutual understanding of program technical requirements."

In preparation for the flight of Apollo 8, NASA and industry technicians at KSC placed CSM 103 atop the Saturn V launch vehicle. The launch escape system was installed the following day; and on October 9 the complete AS-503 space vehicle was rolled out of the Vehicle Assembly Building and moved to the launch pad, where launch preparations were resumed.

NASA Apollo Mission Director William C. Schneider reported completion of all action items pertinent to Apollo 7 assigned by Apollo Program Director Samuel C. Phillips as a result of recommendations by the Apollo Crew Safety Review Board on May 27, 1968.

These actions had included qualification of critical subsystems; a review of the AS-205 launch vehicle test history; a review of Saturn IB 205 and CSM 101 functional interfaces; a manned test readiness review, which was completed at KSC on August 28; and issuance of an Emergency Actions Summary Document containing emergency and contingency situations and appropriate procedures for pad operations, which had won approval on September 27.

Associate Administrator for Manned Space Flight George E. Mueller summarized launch preparations for the near-term missions Apollo 8 and Apollo 9.

Hurricane Gladys had interrupted work on the Apollo 8 spacecraft and launch vehicle and work was now about two days behind schedule. (Because winds from the storm did not exceed Apollo design values, however, Apollo 8 remained at Pad A and was not returned to the assembly building.) Checkout of LM-3 and CSM 104 for Apollo 9 were on schedule. The CSM had been stacked and would undergo combined systems tests shortly. Ascent and descent stages of the lander would be joined immediately after docking tests had been completed.