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Block II CSM's were the only version to fly manned, and they successfully ferried crews to the moon, to the Skylab space station, and to a joint docking with the Russian Soyuz. No production was undertaken after the initial run of 13 Block II capsules - Apollo was abandoned in favor of the Shuttle as the ferry for American manned spaceflight. Forty years later, the Shuttle was to be retired, and a design similar to the Apollo, the CEV, was conceived as the Shuttle's 'replacement'.
Characteristics
Unit Cost $: 77.000 million. Crew Size: 3. Habitable Volume: 6.17 m3. RCS total impulse: 3,774 kgf-sec. Spacecraft delta v: 2,804 m/s (9,199 ft/sec). Electric System: 690.00 kWh. Electric System: 6.30 average kW.
AKA: Command Service Module.
Gross mass: 30,329 kg (66,863 lb).
Unfuelled mass: 11,841 kg (26,104 lb).
Height: 11.03 m (36.18 ft).
Thrust: 97.86 kN (22,000 lbf).
Specific impulse: 314 s.
First Launch: 1964.05.28.
Last Launch: 1975.07.15.
Number: 22 .
Bruce T. Lundin of the Lewis Research Center reported to members on propulsion requirements for various modes of manned lunar landing missions, assuming a 10,000-pound spacecraft to be returned to earth. Lewis mission studies had shown that a launch into lunar orbit would require less energy than a direct approach and would be more desirable for guidance, landing reliability, etc. From a 500,000 foot orbit around the moon, the spacecraft would descend in free fall, applying a constant-thrust decelerating impulse at the last moment before landing. Research would be needed to develop the variable-thrust rocket engine to be used in the descent. With the use of liquid hydrogen, the launch weight of the lunar rocket and spacecraft would be 10 to 11 million pounds. Additional Details: here....
In addition, Goett informed the Committee that the Vega had been eliminated as a possible booster for use in one of the intermediate steps leading to the lunar mission. The primary possibility for the earth satellite mission was now the first-generation Saturn and for the lunar flight the second-generation Saturn.
On February 19, NASA officials again presented the ten-year timetable to the House Committee. A lunar soft landing with a mobile vehicle had been added for 1965. On March 28, NASA Administrator T. Keith Glennan described the plan to the Senate Committee on Aeronautical and Space Sciences. He estimated the cost of the program to be more than $1 billion in Fiscal Year 1962 and at least $1.5 billion annually over the next five years, for a total cost of $12 to $15 billion. Additional Details: here....
To open these discussions, Director Robert R. Gilruth summarized the guidelines: manned lunar reconnaissance with a lunar mission module, corollary earth orbital missions with a lunar mission module and with a space laboratory, compatibility with the Saturn C-1 or C-2 boosters (weight not to exceed 15,000 pounds for a complete lunar spacecraft and 25,000 pounds for an earth orbiting spacecraft), 14-day flight time, safe recovery from aborts, ground and water landing and avoidance of local hazards, point (ten square-mile) landing, 72-hour postlanding survival period, auxiliary propulsion for maneuvering in space, a "shirtsleeve" environment, a three-man crew, radiation protection, primary command of mission on board, and expanded communications and tracking facilities. In addition, a tentative time schedule was included, projecting multiman earth orbit qualification flights beginning near the end of the first quarter of calendar year 1966.
NASA Deputy Administrator Hugh L. Dryden announced that the advanced manned space flight program had been named "Apollo." George M. Low, NASA Chief of Manned Space Flight, stated that circumlunar flight and earth orbit missions would be carried out before 1970. This program would lead eventually to a manned lunar landing and a permanent manned space station. Additional Details: here....
Fundamental decisions were made as a result of this and a previous meeting on September 20.. Additional Details: here....
After reviewing the status of the contractors' Apollo feasibility studies, the Group on Trajectory Analysis discussed studies being made at NASA Centers. An urgent requirement was identified for a standard model of the Van Allen radiation belt which could be used in all trajectory analysis related to the Apollo program,
The Group on Heating, after consideration of NASA and contractor studies currently in progress, recommended experimental investigation of control surface heating and determination of the relative importance of the unknowns in the heating area by relating estimated "ignorance" factors to resulting weight penalties in the spacecraft. The next day, three members of this Group met for further discussions and two areas were identified for more study: radiant heat inputs and their effect on the ablation heatshield, and methods of predicting heating on control surfaces, possibly by wind tunnel tests at high Mach numbers.
The Group on Human Factors considered contractors' studies and investigations being done at NASA Centers. In particular, the Group discussed the STG document, "Project Apollo Life Support Programs," which proposed 41 research projects. These projects were to be carried out by various organizations, including NASA, DOD, industry, and universities. Medical support experience which might be applicable to Apollo was also reviewed.
The Group on Structures and Materials, after reviewing contractors' progress on the Apollo feasibility studies, considered reports on Apollo-related activities at NASA Centers. Among these activities were work on the radiative properties of material suitable for temperature control of spacecraft (Ames), investigation of low-level cooling systems in the reentry module (Langley), experiments on the landing impact of proposed reentry module shapes (Langley), meteoroid damage studies (Lewis), and the definition of suitable design criteria and safety factors to ensure the structural integrity of the spacecraft STG.
The Group on Configurations and Aerodynamics recommended :
David G. Hoag, MIT, personal notes, October 1961..
In addition, the Apollo Project Office, which had been part of the MSC Flight Systems Division, would now report directly to the MSC Director and would be responsible for planning and directing all activities associated with the completion of the Apollo spacecraft project. Primary functions to be performed by the Office would include:
Letter contract No. NAS 9-150, authorizing work on the Apollo development program to begin on January 1, 1962, was signed by NASA and NAA on December 21. Under this contract, NAA was assigned the design and development of the command and service modules, the spacecraft adapter, associated ground support equipment, and spacecraft integration. Formal signing of the contract followed on December 31.
The center couch, including the crewman parachute and survival kit, could be folded out to a sleep position and stowed under either remaining couch. Allowance was made for the crewman to turn over.
Principal problems remaining were the difficulty of removing the center couch and providing the clearances needed for the couch positions specified for various phases of the lunar mission.
Robert O. Piland, Deputy Project Manager
William F. Rector, Special Assistant
Calvin H. Perrine, Flight Technology
Lee N. McMillion, Crew Systems
David L. Winterhalter, Sr., Power Systems
Wallace D. Graves, Mechanical Systems
Milton C. Kingsley, Electrical Systems
(Vacant), Ground Support Equipment
Jack Barnard, Apollo Office at MIT
(Vacant), Reliability and Quality Control
Emory F. Harris, Operations Requirements
Robert P. Smith, Launch Vehicle Integration
Owen G. Morris, Mission Engineering
Marion R. Franklin, Ground Operational Support Systems
Alan B. Kehlet, Engineering
Alan B. Kehlet, Acting Manager, Quality Control and Engineering
Herbert R. Ash, Acting Manager, Business Administration
The launch vehicle required was a single Saturn C-5, consisting of the S-IC, S-II, and S-IVB stages. To provide a maximum launch window, a low earth parking orbit was recommended. For greater reliability, the two-stage-to-orbit technique was recommended rather than requiring reignition of the S-IVB to escape from parking orbit.
The current concepts of the Apollo command and service modules would not be altered. The lunar excursion vehicle (LEV), under intensive study in 1961, would be aft of the service module and in front of the S-IVB stage. For crew safety, an escape tower would be used during launch. Access to the LEV would be provided while the entire vehicle was on the launch pad.
Both Apollo and Saturn guidance and control systems would be operating during the launch phase. The Saturn guidance and control system in the S-IVB would be "primary" for injection into the earth parking orbit and from earth orbit to escape. Provisions for takeover of the Saturn guidance and control system should be provided in the command module. Ground tracking was necessary during launch and establishment of the parking orbit, MSFC and GSFC would study the altitude and type of low earth orbit.
The LEV would be moved in front of the command module "early" in the translunar trajectory. After the S-IVB was staged off the spacecraft following injection into the translunar trajectory, the service module would be used for midcourse corrections. Current plans were for five such corrections. If possible, a symmetric configuration along the vertical center line of the vehicle would be considered for the LEV. Ingress to the LEV from the command module should be possible during the translunar phase. The LEV would have a pressurized cabin capability during the translunar phase. A "hard dock" mechanism was considered, possibly using the support structure needed for the launch escape tower. The mechanism for relocation of the LEV to the top of the command module required further study. Two possibilities were discussed: mechanical linkage and rotating the command module by use of the attitude control system. The S-IVB could be used to stabilize the LEV during this maneuver.
The service module propulsion would be used to decelerate the spacecraft into a lunar orbit. Selection of the altitude and type of lunar orbit needed more study, although a 100-nautical-mile orbit seemed desirable for abort considerations.
The LEV would have a "point" landing (±½ mile) capability. The landing site, selected before liftoff, would previously have been examined by unmanned instrumented spacecraft. It was agreed that the LEV would have redundant guidance and control capability for each phase of the lunar maneuvers. Two types of LEV guidance and control systems were recommended for further analysis. These were an automatic system employing an inertial platform plus radio aids and a manually controlled system which could be used if the automatic system failed or as a primary system.
The service module would provide the prime propulsion for establishing the entire spacecraft in lunar orbit and for escape from the lunar orbit to earth trajectory. The LEV propulsion system was discussed and the general consensus was that this area would require further study. It was agreed that the propulsion system should have a hover capability near the lunar surface but that this requirement also needed more study.
It was recommended that two men be in the LEV, which would descend to the lunar surface, and that both men should be able to leave the LEV at the same time. It was agreed that the LEV should have a pressurized cabin which would have the capability for one week's operation, even though a normal LOR mission would be 24 hours. The question of lunar stay time was discussed and it was agreed that Langley should continue to analyze the situation. Requirements for sterilization procedures were discussed and referred for further study. The time for lunar landing was not resolved.
In the discussion of rendezvous requirements, it was agreed that two systems be studied, one automatic and one providing for a degree of manual capability. A line of sight between the LEV and the orbiting spacecraft should exist before lunar takeoff. A question about hard-docking or soft-docking technique brought up the possibility of keeping the LEV attached to the spacecraft during the transearth phase. This procedure would provide some command module subsystem redundancy.
Direct link communications from earth to the LEV and from earth to the spacecraft, except when it was in the shadow of the moon, was recommended. Voice communications should be provided from the earth to the lunar surface and the possibility of television coverage would be considered.
A number of problems associated with the proposed mission plan were outlined for NASA Center investigation. Work on most of the problems was already under way and the needed information was expected to be compiled in about one month.
(This meeting, like the one held February 13-15, was part of a continuing effort to select the lunar mission mode).
For the service module RCS, a quadruple arrangement was chosen which was basically similar to the command module RCS except that squib valves and burst discs were eliminated.
Concurrently, a number of NAA latching concepts were in preparation for presentation to NASA, including that of an outward-opening, quick- opening crew door without an outer emergency panel. This design, however, had weight and complexity disadvantages, as well as requiring explosive charges.
A study on the direct vision requirement for lunar landing showed that, to have a simultaneous direct view of the lunar landing point and the landing feet without changing the spacecraft configuration, a periscope with a large field of view integrated with a side window would be needed. A similar requirement on the general-purpose telescope could thus be eliminated, reducing the complexity of the telescope design.
Another study showed that, with an additional weight penalty of from five to ten pounds, an optical drift indicator for use after parachute deployment could easily be incorporated into the general-purpose telescope.
One 16-mm camera was also planned for the spacecraft. This camera would be positioned level with the commander's head and directed at the main display panel. It could be secured to the telescope for recording motion events in real time such as rendezvous, docking, launch and recovery of a lunar excursion module, and earth landing; it could be hand-held for extravehicular activity.
Another closed-hatch configuration under consideration would entirely eliminate the CM airlock. Astronauts transferring to and from the lunar excursion module would be in a pressurized environment constantly.
Among the items deleted from the command module (CM) were exercise and recreation equipment, personal parachutes and parachute containers located in the couches, individual survival kits, solar radiation garments, and eight-ball displays. A telescope, cameras and magazines considered scientific equipment, and a television monitor were deleted from the CM instrumentation system.
A review of body angles used for the current couch geometry disclosed that the thigh-to-torso angle could be closed sufficiently for a brief period during reentry to shorten the overall couch length by the required travel along the Z-Z axis. The more acute angle was desirable for high g conditions. This change in the couch adjustment range, as well as a revision in the lower leg angle to gain structure clearance, would necessitate considerable couch redesign.
Also, Collins awarded a contract to the Leach Corporation for the development of command and service module (CSM) data storage equipment. The tape recorders must have a five-hour capacity for collection and storage of data, draw less than 20 watts of power, and be designed for in-flight reel changes.
RCA Service Company to design and build two vacuum chambers at MSC. The facility was used in astronaut training and spacecraft environmental testing. using carbon arc: lamps, the chambers simulated the sun's intensity, permitting observation of the effects of solar heating encountered on a lunar mission. At the end of July, MSC awarded RCA another contract (worth $3,341,750) for these solar simulators.
Other items received considerable attention: A six-foot umbilical hose would be adequate for the astronaut in the CM. The location of spacecraft water, oxygen, and electrical fittings was judged satisfactory, as were the new couch assist handholds. The astronaut's ability to operate the environmental control system (ECS) oxygen flow control valve while couched and pressurized was questionable. Therefore, it was decided that the ECS valve would remain open and that the astronaut would use the suit control valve to regulate the flow. It was also found that the hand controller must be moved about nine inches forward.
Use of the fixed couch required relocation of the main and side display panels and repositioning of the translational and rotational hand controllers. During rendezvous and docking operations, the crew would still have to adjust their normal body position for proper viewing.
There were a number of other cases wherein North American and ASPO agreed on procedures which simply required formal statements of what would be done. Examples of these were:
"The consequences," Bryant concluded, "of imposing an ever-increasing number of these flight restrictions is obvious - the eventual loss of almost all operational flexibility. The only solution is . . . (a) meticulous examination of every constraint which tends to reduce the number of available launch opportunities," looking toward eliminating "as many as possible."
On the following day, the Center informed North American also that a new mechanical clock timer system would be provided in the CM for indicating elapsed time from liftoff and predicting time to and duration of various events during the mission.
Recent load analysis at North American placed the power required for a 14-day mission at 577 kilowatt-hours, a decrease of about 80 kilowatt-hours from earlier estimates.
On this same day, MSC awarded a $183,152 contract to Wyle Laboratories to construct a high-intensity acoustic facility, also for testing spacecraft parts. The facility would generate noise that might be encountered in space flight.
Despite the contractor's findings, MSC concluded that there was no need for an RE warning system aboard the spacecraft, believing that radiation warning could be handled more effectively by ground systems. But MSC did concur in the recommendation for a combined proton direction and external environment detection system and authorized North American to proceed with its design and development.
All sequencing was normal. The tower-jettison motor sent the escape tower into a proper ballistic trajectory. The drogue parachute deployed as programmed, followed by the pilot parachute and main parachutes. The test lasted 165.1 seconds. The postflight investigation disclosed only one significant problem: exhaust impingement that resulted in soot deposits on the CM.
MSC directed North American to proceed with the tower flap as its prime effort, and attempt to solve the stability problem at the earliest possible date. MSC's Engineering and Development Directorate resumed its study of both configurations, with an in-depth analysis of the canard system, in case the stability problem on the tower flap could not be solved by the end of the year.
There would be two ways for the astronauts to get from one spacecraft to the other. The primary mode involved docking and passage through the transfer tunnel. An emergency method entailed crew and payload transfer through free space. The CSM would take an active part in translunar docking, but both spacecraft must be able to take the primary role in the lunar orbit docking maneuver. A single crewman must be able to carry out the docking maneuver and crew transfer.
Penetration of the thicker targets was about 13.970 millimeters (0.55 inch). In the thinner targets, the ablator was pierced. Debris tore through the steel honeycomb and produced pinholes on the rear steel sheet. Damage to the ablator was confined to two or three honeycomb cells and there was no cracking or spalling on the surface.
Tests at Ames of thermal performance of the ablation material under high shear stress yielded favorable preliminary results.
Further analysis of the management system was necessary to determine changes needed in the checkout unit.
Three days later, Shea reported to the MSC Senior Staff that Apollo landings would be primarily on water. The only exceptions, he said, would be pad aborts and emergency landings. With this question of "wet" versus "dry" landing modes settled, Christopher C. Kraft, Jr., Assistant Director for Flight Operations, brought up the unpleasant problem of the CM's having two stable attitudes while afloat - and especially the apex-down one. This upside-down attitude, Kraft emphasized, submerged the vehicle's recovery antennas and posed a very real possibility of flooding in rough seas. Shea countered that these problems could be "put to bed" by using some type of inflatable device to upright the spacecraft.
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. Additional Details: here....
For the first time, three representative Apollo space suits were used in the CM couches. Pressurized suit demonstrations, with three suited astronauts lying side by side in the couches, showed that the prototype suit shoulders and elbows overlapped and prevented effective operation of the CM displays and controls. Previous tests, using only one suited subject, had indicated that suit mobility was adequate. Gemini suits, tested under the same conditions, proved much more usable. Moreover, using Gemini suits for Apollo earth orbital missions promised a substantial financial saving. As a result of further tests conducted in May, the decision was made to use the Gemini suits for these missions. The existing Apollo space suit contract effort was redirected to concentrate on later Apollo flights. A redesign of the Apollo suit shoulders and elbows also was begun.
Each group represented had a different interpretation of the reasons for the excessively high surface recession. The conclusion was that a second flight of the heatshield materials on the Scout would not particularly improve the understanding of the material's performance because of the limited variation in reentry trajectory and flight conditions obtainable with the Scout vehicle.
Personnel from MSC, MSFC, KSC, OMSF, and North American attended the meeting. Included in the discussions were a review of the EDS design for both the launch vehicle and spacecraft along with related ground support equipment; a review of the differences of design and checkout concepts; and a review of EDS status lights in the spacecraft.
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.
During the same period, however, the Systems Engineering Division (SED) reported "progress" in solving the radiator problem. SED stated that some "disagreement" existed on the radiator's capability. North American predicted a five-day capability; CSD placed the mission's limit at about two days. SED ordered further testing on the equipment to reconcile this difference.
On the same day, the Center directed North American to put a standard mechanical clock (displaying Greenwich Mean Time) in the lower equipment bay of the CM. (The spacecraft also had an elapsed time device on the main display console.)
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.
Further testing during the following month reinforced these findings. But because sequential deployment would degrade reliability of the system, North American held that the bags must upright the spacecraft irrespective of the order of their inflation. Stevens' investigators would continue their program, examining the CM's characteristics under a variety of weight and center of gravity conditions.
These values, ASPO Manager Joseph F. Shea emphasized, were based on the 8.3-day reference mission and on emergency dose limits previously set forth. They were not to be included in overall reliability goals for the spacecraft, nor were they to be met by weight increases or equipment relocations.
| Spacecraft | Development | Unit Cost |
|---|---|---|
| Block I | $840,000 | $185,000 |
| Block II | $960,000 | $112,000 |
| Blocks I & II | $1,050,000 | $111,000 |
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.
Taylor requested items for consideration be submitted no later than April 27, 1965, and pointed out some specifics which might be considered: