Encyclopedia Astronautica
CSM Guidance


CSM Guidance Development Diary

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CSM Guidance Chronology


1959 September - .
  • MIT study of the guidance and control design for a variety of space missions - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Summary: A study of the guidance and control design for a variety of space missions began at the MIT Instrumentation Laboratory under a NASA contract..

1960 November 22 - .
  • MIT navigation and guidance support for Project Apollo - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. STG held a meeting at Goddard Space Flight Center to discuss a proposed contract with MIT Instrumentation Laboratory for navigation and guidance support for Project Apollo. The proposed six-month contract for $100,000 might fund studies through the preliminary design stage but not actual hardware. Milton B. Trageser of the Instrumentation Laboratory presented a draft work statement which divided the effort into three parts: midcourse guidance, reentry guidance, and a satellite experiment feasibility study using the Orbiting Geophysical Observatory. STG decided that the Instrumentation Laboratory should submit a more detailed draft of a work statement to form the basis of a contract. In a discussion the next day, Robert G. Chilton of STG and Trageser clarified three points:

    1. The current philosophy was that an onboard computer program for a normal mission sequence would be provided and would be periodically updated by the crew. If the crew were disabled, the spacecraft would continue on the programmed flight for a normal return. No capability would exist for emergency procedures.
    2. Chilton emphasized that consideration of the reentry systems design should include all the guideline requirements for insertion monitoring by the crew, navigation for aborted missions, and, in brief, the whole design philosophy for manned flight.
    3. The long-term objective of a lunar landing mission should be kept in mind although design simplicity was of great importance.
    Chilton and Trageser agreed that the purpose of the Apollo program was the development of manned space flight system capability, not simply circumnavigation of the moon with an encapsulated man.

1960 December 2 - .
  • Study program on the guidance aspects of Project Apollo - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Milton B. Trageser of MIT Instrumentation Laboratory transmitted to Charles J. Donlan of STG the outline of a study program on the guidance aspects of Project Apollo. He outlined what might be covered by a formal proposal on the Apollo spacecraft guidance and navigation contract discussed by STG and Instrumentation Laboratory representatives on November 22.

1960 December 22 - .
  • MIT proposal for a study of a navigation and guidance system for Apollo - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Summary: The MIT Instrumentation Laboratory submitted a formal proposal to NASA for a study of a navigation and guidance system for the Apollo spacecraft..

1961 February 7 - .
  • MIT selected for a study of a navigation and guidance system for the Apollo spacecraft - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Summary: NASA selected the Instrumentation Laboratory of MIT for a six-month study of a navigation and guidance system for the Apollo spacecraft..

1961 April 10-12 - .
  • Apollo Technical Liaison Group for Trajectory Analysis commented on Apollo specification - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. The Apollo Technical Liaison Group for Trajectory Analysis met at STG and began preparing material for the Apollo spacecraft specification. It recommended:

    • STG should take the initiative with NASA Headquarters in delegating responsibility for setting up and updating a uniform model of astronomical constants.
    • The name of the Group should be changed to Mission Analysis to help clarify its purpose.
    • A panel should be set up to determine the scientific experiments which could be done on board, or in conjunction with the orbiting laboratory, so that equipment, weight, volumes, laboratory characteristics, etc., might be specified

1961 July-September - .
  • Work statements for the Apollo guidance and navigation system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Summary: The MIT Instrumentation Laboratory and NASA completed the work statements for the Laboratory's program on the Apollo guidance and navigation system and the request for quotation for industrial support was prepared..

1961 July - .
  • Polaris program experience studied for Apollo - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Ralph Ragan of the MIT Instrumentation Laboratory, former director of the Polaris guidance and navigation program, in cooperation with Milton B. Trageser of the Laboratory and with Robert O. Piland, Robert C. Seamans, Jr., and Robert G. Chilton, all of NASA, had completed a study of what had been done on the Polaris program in concept and design of a guidance and navigation system and the documentation necessary for putting such a system into production on an extremely tight schedule. Using this study, the group worked out a rough schedule for a similar program on Apollo.

1961 August 9 - .
  • First Apollo development contract - . Nation: USA. Program: Apollo. Class: Moon. Type: Manned lunar spacecraft. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. NASA selected MIT's Instrumentation Laboratory to develop the guidance-navigation system for Project Apollo spacecraft. This first major Apollo contract was required since guidance-navigation system is basic to overall Apollo mission. The Instrumentation Laboratory of MIT, a nonprofit organization headed by C. Stark Draper, has been involved in a variety of guidance and navigation systems developments for 20 years. This first major Apollo contract had a long lead-time, was basic to the overall Apollo mission, and would be directed by STG.

1961 September 12-13 - .
  • Progress review of the Apollo navigation and guidance system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Representatives of STG and NASA Headquarters visited the Instrumentation Laboratory of MIT to discuss the contract awarded to the Laboratory on August 9 and progress in the design and development of the Apollo spacecraft navigation and guidance system. They mutually decided that a draft of the final contract should be completed for review at Instrumentation Laboratory by October 2 and the contract resolved by October 9. Revisions were to be made in the Statement of Work to define more clearly details of the contract. Milton B. Trageser of the Laboratory, in the first month's technical progress report, gave a brief description of the first approach to the navigation and guidance equipment and the arrangement of the equipment within the spacecraft. He also presented the phases of the lunar flight and the navigation and guidance functions or tasks to be performed. Other matters discussed were a space sextant and making visual observations of landmarks through cloud cover.

1961 September - .
  • Concepts of Apollo navigation equipment described - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Richard H. Battin published MIT Instrumentation Laboratory Report R-341, "A Statistical Optimizing Navigation Procedure for Space Flight," describing the concepts by which Apollo navigation equipment could make accurate computations of position and velocity with an onboard computer of reasonable size.

1961 October 31 - .
  • New information on the Apollo spacecraft roll inertia, pitch and yaw inertia, and attitude jets - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Summary: Robert G. Chilton of STG gave the MIT Instrumentation Laboratory new information based on NASA in- house studies on the Apollo spacecraft roll inertia, pitch and yaw inertia, and attitude jets.

    David G. Hoag, MIT, personal notes, October 1961..


1961 November 7-9 - .
  • MIT contract for the Apollo navigation and guidance system discussed - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Source Selection. Representatives of MSC and NASA Headquarters visited the MIT Instrumentation Laboratory to discuss clauses in the contract for the Apollo navigation and guidance system, technical questions proposed by MSC, and work in progress. Topics discussed included the trajectories for the SA-7 and SA-8 flights and the estimated propellant requirements for guidance attitude maneuvers and velocity changes for the lunar landing mission. Presentations were made on the following subjects by members of the Laboratory staff: the spacecraft gyro, Apollo guidance computer logic design, computer displays and interfaces, guidance computer programming, horizon sensor experiments, and reentry guidance.

1961 November 29-30 - . LV Family: Saturn V. Launch Vehicle: Saturn V.
  • Emergency switchover from Saturn to Apollo guidance as backup discussed - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: On a visit to Marshall Space Flight Center by MIT Instrumentation Laboratory representatives, the possibility was discussed of emergency switchover from Saturn to Apollo guidance systems as backup for launch vehicle guidance..

1961 December 18-19 - .
  • First design-study Apollo space sextant produced - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Fred T. Pearce, Jr., of MSC visited the MIT Instrumentation Laboratory to discuss the first design-study space sextant produced at the Laboratory, The instrument was intended to be used with the guidance computer. The working mockup was demonstrated and the problem of the effect of the vehicle motion on the sextant was discussed.

1962 January-February - .
  • Requests for Quotation for Apollo guidance and navigation system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. The Requests for Quotation on production contracts for major components of the Apollo spacecraft guidance and navigation system, comprising seven separate items, were released to industry by the MIT Instrumentation Laboratory. (The Source Evaluation Board, appointed on January 31, began its work during the week of March 5 and contractors were selected on May 8.)

1962 March-November - .
  • Apollo guidance and navigation system defined - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. The Apollo guidance and navigation system was defined in more detail as more information from NASA MIT studies was received on new requirements for the system. As a result, the scope of the component development tasks given to all the guidance and navigation subcontractors was substantially increased.

1962 May 4 - .
  • Source Evaluation Board for selecting Apollo navigation and guidance completed its evaluation - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. The Source Evaluation Board for selecting Apollo navigation and guidance components subcontractors completed its evaluation of bids and technical proposals and submitted its findings to NASA Headquarters. Preliminary presentation of the Board's findings had been made to NASA Administrator James E. Webb on April 5.

1962 May 8 - .
  • Three contractors for the Apollo guidance and navigation system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. NASA announced the selection of three companies for the negotiation of production contracts for major components of the Apollo spacecraft guidance and navigation system under development by the MIT Instrumentation Laboratory. The largest of the contracts, for $16 million, would be negotiated with AC Spark Plug Division of General Motor Corporation for fabrication of the inertial, gyroscope-stabilized platform of the Apollo spacecraft; for development and construction of ground support and checkout equipment; and for assembling and testing all parts of the system. The second contract, for $2 million, would be negotiated with the Raytheon Company to manufacture the digital computer aboard the spacecraft. Under the third contract, for about $2 million, Kollsman Instrument Corporation would build the optical subsystems, including a space sextant, sunfinders, and navigation display equipment.

1962 May - .
  • Apollo emergency flight mode for lunar mission reentry - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. A feasibility study was completed by NAA on the ballistic (zero-lift) maneuver as a possible emergency flight mode for lunar mission reentry. Based upon single-pass and 12 g maximum load-factor criteria, the guidance corridor would be nine nautical miles. When atmospheric density deviations were considered (+/- 50 percent from standard), the allowable corridor would be reduced to four nautical miles. Touchdown dispersions within the defined corridor exceeded 2500 nautical miles.

1962 June 18 - .
  • Location of the onboard space sextant in the Apollo command module changed - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. As the result of considerable joint engineering effort and discussion by NAA and MIT Instrumentation Laboratory, the location of the onboard space sextant in the command module was changed from the main instrument panel to the wall of the lower equipment bay. The instrument would penetrate the hull on the hot side during reentry and the navigator would have to leave his couch to make navigation sightings and to align the inertial measurement unit.

1962 Summer-Fall - .
  • Microcircuits to be used on the Apollo computer - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: NASA and MIT agreed that the Instrumentation Laboratory would use the microcircuit for the prototype Apollo onboard computer. The Fairchild Controls Corporation microcircuit was the only one available in the United States..

1962 August 6 - .
  • MIT ordered Honeywell computer for work on the Apollo spacecraft navigation system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. The MIT Instrumentation Laboratory ordered a Honeywell 1800 electronic computer from the Minneapolis- Honeywell Regulator Company's Electronic Data Processing Division for work on the Apollo spacecraft navigation system. After installation in 1963, the computer would aid in circuitry design of the Apollo spacecraft computer and would also simulate full operation of a spaceborne computer during ground tests.

1962 August - .
  • Effects of crew motions on Apollo attitude control negligible - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: An NAA study indicated that the effects of crew motions on spacecraft attitude control would be negligible..

1962 Early September - .
  • Wooden mockup of Apollo command module received - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC reported that it had received a completed wooden mockup of the interior arrangement of the Apollo command module (CM). An identical mockup was retained at NAA for design control. Seven additional CM and service module (SM) mockups were planned: a partial SM and partial adapter interface, CM for exterior cabin equipment, complete SM, spacecraft for handling and transportation (two), crew support system, and complete CSM's. A mockup of the navigation and guidance equipment had been completed. A wooden mockup of the lunar excursion module exterior configuration was fabricated by NAA as part of an early study of spacecraft compatibility requirements.

1962 September - .
  • Apollo lunar excursion module guidance system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC reported that the lunar excursion module guidance system was expected to use as many components as possible identical to those in the command and service modules. Studies at the MIT Instrumentation Laboratory indicated that the changes required would simplify the computer and continue the use of the same inertial measurement unit and scanning telescope.

1962 October 10 - .
  • Honeywell subcontract for Apollo stabilization and control system amended - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: The Minneapolis-Honeywell Regulator Company letter subcontract for the Apollo stabilization and control system was suspended by NAA and amended in accordance with the current design concepts,.

1962 November 9 - .
  • Raytheon contracted for the Apollo spacecraft guidance computer - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: The Manned Spacecraft Center (MSC) and the Raytheon Company came to terms on the definitive contract for the Apollo spacecraft guidance computer..

1962 November 19 - .
  • Requirements for the Apollo CSM stabilization and control system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: North American defined requirements for the command and service modules (CSM) stabilization and control system..

1962 November - .
  • First Apollo CM inertial reference integrating gyro - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. AC Spark Plug Division of General Motors Corporation assembled the first CM inertial reference integrating gyro (IRIG) for final tests and calibration. Three IRIGs in the CM navigation and guidance system provided a reference from which velocity and attitude changes could be sensed. Delivery of the unit was scheduled for February 1963.

1962 December 5 - .
  • Spacesuited astronaut use of Apollo navigation equipment studied - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. At a meeting held at Massachusetts Institute of Technology (MIT) Instrumentation Laboratory, representatives of MIT, MSC, Hamilton Standard Division, and International Latex Corporation examined the problem of an astronaut's use of optical navigation equipment while in a pressurized suit with helmet visor down. MSC was studying helmet designs that would allow the astronaut to place his face directly against the helmet visor; this might avoid an increase in the weight of the eyepiece. In February 1963, Hamilton Standard recommended adding corrective devices to the optical system rather than adding corrective devices to the helmet or redesigning the helmet. In the same month, ASPO set 52.32 millimeters 2.06 inches as the distance of the astronaut's eye away from the helmet. MIT began designing a lightweight adapter for the navigation instruments to provide for distances of up to 76.2 millimeters (3 inches).

1962 December 26 - .
  • Honeywell submitted proposal for the Apollo stabilization and control system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: The Minneapolis-Honeywell Regulator Company submitted to North American cost proposal and design specifications on the Apollo stabilization and control system, based upon the new Statement of Work drawn up on December 17..

1963 February 8 - .
  • Definitive contract let to Raytheon Company for command module (Apollo CM) onboard digital computer - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC issued a definitive contract for $15,029,420 to the Raytheon Company, Space and Information Systems Division, to design and develop the CM onboard digital computer. The contract was in support of the MIT Instrumentation Laboratory, which was developing the Apollo guidance and navigation systems. Announcement of the contract was made on February 11.

1963 February 11 - .
  • The first inertial reference integrating gyro for Apollo was accepted - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: The first inertial reference integrating gyro produced by AC Spark Plug was accepted by NASA and delivered to the MIT Instrumentation Laboratory..

1963 February 13 - .
  • Reorganization of Apollo SPO - . Nation: USA. Related Persons: Johnson, Caldwell; Maynard. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance. In a reorganization of ASPO, MSC announced the appointment of two deputy managers. Robert O. Piland, deputy for the LEM, and James L. Decker, deputy for the CSM, would supervise cost, schedule, technical design, and production. J. Thomas Markley was named Special Assistant to the Apollo Manager, Charles W. Frick. Also appointed to newly created positions were Caldwell C. Johnson, Manager, Spacecraft Systems Office, CSM; Owen E. Maynard, Acting Manager, Spacecraft Systems Office, LEM; and David W. Gilbert, Manager, Spacecraft Systems Office, Guidance and Navigation.

1963 February 21 - .
  • MSC issued a Request for Proposals (due by March 13) for a radiation altimeter system - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC issued a Request for Proposals (due by March 13) for a radiation altimeter system. Greater accuracy than that provided by available radar would be needed during the descent to the lunar surface, especially in the last moments before touchdown. Preliminary MSC studies had indicated the general feasibility of an altimeter system using a source-detector-electronics package. After final selection and visual observation of the landing site, radioactive material would be released at an altitude of about 30 meters 100 feet and allowed to fall to the surface. The detector would operate in conjunction with electronic circuitry to compute the spacecraft's altitude. Studies were also under way at MSC on the possibility of using laser beams for range determination.

1963 February 27 - .
  • Elgin subcontract for central timing equipment for the Apollo spacecraft - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Elgin National Watch Company received a subcontract from North American for the design and development of central timing equipment for the Apollo spacecraft. (This equipment provided time-correlation of all spacecraft time-sensitive events. Originally, Greenwich Mean Time was to be used to record all events, but this was later changed.

1963 March 6 - .
  • First Block I Apollo pulsed integrating pendulum accelerometer delivered - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. The first Block I Apollo pulsed integrating pendulum accelerometer, produced by the Sperry Gyroscope Company, was delivered to the MIT Instrumentation Laboratory. (Three accelerometers were part of the guidance and navigation system. Their function was to sense changes in spacecraft velocity.)

1963 March - .
  • MSC sent MIT and Grumman radar configuration requirements for the Apollo LEM - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. MSC sent MIT and Grumman radar configuration requirements for the LEM. The descent equipment would be a three-beam doppler radar with a two-position antenna. Operating independently of the primary guidance and navigation system, it would determine altitude, rate of descent, and horizontal velocity from 7,000 meters (20,000 feet) above the lunar surface. The LEM rendezvous radar, a gimbaled antenna with a two-axis freedom of movement, and the rendezvous transponder mounted on the antenna would provide tracking data, thus aiding the LEM to intercept the orbiting CM. The SM would be equipped with an identical rendezvous radar and transponder.

1963 May 6 - .
  • Apollo LEM manual control simulated - . Nation: USA. Related Persons: Carpenter; Schirra; Armstrong; McDivitt; See; White; Conrad; Young. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Simulator. Astronauts M. Scott Carpenter, Walter M. Schirra, Jr., Neil A. Armstrong, James A. McDivitt, Elliot M. See, Jr., Edward H. White II, Charles Conrad, Jr., and John W. Young participated in a study in LTV's Manned Space Flight Simulator at Dallas, Tex. Under an MSC contract, LTV was studying the astronauts' ability to control the LEM manually and to rendezvous with the CM if the primary guidance system failed during descent.

1963 May 23 - .
  • Major redesign of the Apollo guidance computer - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. Summary: MIT suggested a major redesign of the Apollo guidance computer to make the CM and LEM computers as similar as possible. NASA approved the redesign and the Raytheon Company, subcontractor for the computer, began work..

1963 June 14 - .
  • Definitive contract for the navigation and guidance equipment for the Apollo CM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: NASA Headquarters approved a definitive contract for $35,844,550 with AC Spark Plug for the manufacture and testing of navigation and guidance equipment for the CM. This superseded a letter contract of May 30, 1962..

1963 June 22 - .
  • Design of the Apollo CM's stabilization and control system frozen - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: North American officially froze the design of the CM's stabilization and control system..

1963 September 6 - .
  • Contract with Kollsman for Apollo CM guidance and navigation optical equipment - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC announced a $7.658 million definitive contract with Kollsman Instrument Corporation for the CM guidance and navigation optical equipment, including a scanning telescope, sextant, map and data viewer, and related ground support equipment. MSC had awarded Kollsman a letter contract on May 28, 1962, and had completed negotiations for the definitive contract on March 29, 1963. "The newly signed contract calls for delivery of all hardware to AC Spark Plug by August 1, 1964."

1963 October 10 - .
  • Results of tests performed by astronauts in the Manned Space Flight Mission Simulator - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. LTV announced the results of tests performed by astronauts in the Manned Space Flight Mission Simulator in Dallas, Tex. These indicated that, should the primary guidance and navigation system fail, LEM pilots could rendezvous with the CM by using a circular slide rule to process LEM radar data.

1963 October 18 - .
  • Selection of five organizations for Apollo LEM guidance and navigation equipment - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. NASA Headquarters announced the selection of five organizations for contract negotiations totaling $60 million for the development, fabrication, and testing of LEM guidance and navigation equipment: (1) MIT, overall direction; (2) Raytheon, LEM guidance computer; (3) AC Spark Plug, inertial measurement unit, gyroscopes, navigation base, power and servo assembly, coupling display unit, and assembly and testing of the complete guidance and navigation system; (4) Kollsman Instrument Corporation, scanning telescope, sextant, and map and data viewer; and (5) Sperry Gyroscope Company, accelerometers. (All five had responsibility for similar equipment for the CSM as well.)

1964 February 6 - .
  • Honeywell developed an all-attitude display unit for the Apollo CM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Minneapolis-Honeywell Regulator Company reported it had developed an all-attitude display unit for the CM to monitor the guidance and navigation system and provide backup through the stabilization and control system. The Flight Director Attitude Indicator (or "eight-ball") would give enough information for all spacecraft attitude maneuvers during the entire mission to be executed manually, if necessary.

1964 February 16-March 21 - .
  • Plan for changing the relationship of the Apollo navigation and guidance contractors - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC completed and forwarded to NASA Headquarters a plan for changing the relationship of the navigation and guidance contractors. AC Spark Plug would become the principal contractor, with the Raytheon Company and Kollsman Instrument Corporation as subcontractors. MIT would still have primary responsibility for system design and analysis.

1964 February 27-29 - .
  • Amendments to AC Spark Plug contract for Apollo - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC and AC Spark Plug negotiated amendments to AC's contract for a research and development program for inertial reference integrating gyroscopes. The amendments covered cost overruns, an additional 30 pieces of hardware, and conversion of the contract to an incentive-fee type (target price, $3.465 million; ceiling price, $3.65 million).

1964 October 12 - .
  • Apollo LEM guidance and navigation ground rules for the coasting phase of the mission - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. MSC notified Grumman of several additional LEM guidance and navigation ground rules that were applicable to the coasting phase of the mission. During this portion of the flight, the LEM abort guidance system must be capable of giving attitude information and of measuring velocity changes. Navigational data required to take the LEM out of the coasting phase and to put it on an intercept course with the CSM would be provided by the CSM's rendezvous radar and its guidance and navigation system, and through the Manned Space Flight Network back on earth.

1964 October 14 - .
  • First Apollo guidance system shipped - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. In a letter to NASA Administrator James E. Webb, AC Spark Plug reported that the first Apollo guidance system completed acceptance testing and was shipped at 11:30 p.m. and arrived at Downey, California, early the following day. AC reported that in more than 2,000 hours of operation they had found the system to be "remarkably reliable, accurate and simple to operate."

1964 October 15 - .
  • Consequences of eliminating the Apollo CSM rendezvous radar - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Descent Propulsion; LM Guidance. MSC's Systems Engineering Division reported on the consequences of eliminating the command and service module (CSM) rendezvous radar:

    Coasting period:
    During this phase of the mission, the rendezvous radar on the CSM would be used to track the LEM and the rendezvous radar on the LEM would be used to track the CSM. With the use of Mission Control through the Manned Space Flight Network (MSFN), three sources of information could be used as a vote for guidance system monitoring. Without the CSM rendezvous radar, the monitoring task would become more difficult; however, this was not to imply that it was impossible. The conclusion was that CSM rendezvous radar was highly desirable, but not absolutely necessary.
    Lunar descent and ascent:
    During powered flight, the CSM would be tracking the LEM. This was desirable because if the LEM guidance computer (LGC) failed, it was very doubtful that the astronauts could manually acquire radar lock-on with the CSM. Also, if the LEM rendezvous radar failed, CSM lock-on would be highly desirable. There were several alternative solutions to this problem. First of all, Mission Control through the MSFN could relieve the problem. If this did not satisfy all requirements, it was possible for the LEM rendezvous radar to track the CSM during powered descent and ascent. If the LGC then failed, the tracking acquisition would no longer be a problem. In summary, there did appear to be other ways of fulfilling the functions of the CSM rendezvous radar during the powered phases.
    Lunar surface:
    While the LEM was on the lunar surface, it would be tracked with the CSM rendezvous radar in order to update launch conditions. This could be accomplished by the LEM tracking the CSM and the MSFN.
    Rendezvous:
    This was the most critical phase for the use of the rendezvous radar on the CSM. If the LEM primary guidance system should fail (i.e., the LGC, inertial measurement unit (IMU), and LEM rendezvous radar), navigation information for long-range midcourse corrections would be provided by the rendezvous radar on the CSM. The MSFN, however, could supply this information. The terminal rendezvous maneuver would become a problem if the LEM rendezvous radar failed and there was not a rendezvous radar on the CSM. It had not been established that the MSFN could supply the required terminal rendezvous information. If MSFN could, a restricted mission profile would have to be employed. There were other methods of supplying terminal rendezvous information such as optical tracking. The scanning telescope or sextant on the CSM could be used with the IMU and Apollo guidance computer on the CSM to derive navigation information, meaning that the LEM would require flashing lights. There was a delta-V penalty associated with using angle-only information in place of range range rate and angle information, its importance depending on the accuracy of the angle data and the range/range rate data.

1964 October 17 - .
  • IBM contract for the Apollo backup computer - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: MSC and International Business Machines Corporation (IBM) negotiated a $1,500,000 fixed-price contract for the Apollo guidance and navigation system backup computer..

1964 October 27 - .
  • North American to halt procurement of a Apollo CM simulator - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC ordered North American to halt procurement of a CM simulator. Instead, the company was to begin a simulator program using the two existing evaluator-type CMs in conjunction with the digital-analog computer facility. These evaluators would be used to verify the guidance and navigation and stabilization and control system software, and to analyze crew tasks and failure effects.

1964 November 9 - .
  • Apollo guidance and navigation equipment contract amended - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: NASA and AC Spark Plug amended the company's contract for guidance and navigation equipment. The change embodied an incentive clause, based on a cost-schedule-performance scheme, and placed the estimated cost of the contract at $235,000,000..

1964 November 23-25 - .
  • Ground test program for the Apollo LEM guidance and navigation subsystem - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance. MSC and Grumman reviewed the ground test program for the LEM guidance and navigation subsystem (including radar). All major milestones for hardware qualification would be met by the revised test logic, and both LEM and CSM radar were expected to be delivered on time. The major problem area was permissible deviations from fully qualified parts for pre-production equipment. Since this was apparently true for all LEM electronics equipment, it was recommended that an overall plan be approved by ASPO.

1965 February 23 - .
  • IBM to design backup guidance and navigation computer for the Apollo CM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: NASA awarded a fixed-price contract (worth l.5 million) to IBM to design a backup guidance and navigation computer for the Apollo CM..

1965 February - .
  • Pointing accuracy of Apollo control system at transearth injection - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Because of a change in the size of the entry corridor, North American technicians sought to determine whether they might relax the requirements for pointing accuracy of the stabilization and control system at transearth injection. They could not. To ensure a delta-V reserve, the accuracy requirement must remain unchanged.

1965 March 3 - .
  • Definitive contract for guidance and navigation systems for the Apollo CM and LEM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. NASA and General Motors' AC Spark Plug Division signed the definitive contract (cost-plus-incentive-fee type) for primary guidance and navigation systems for the Apollo spacecraft (both CMs and LEMs). The agreement, extending through December 1969, covered manufacturing and testing of the systems.

1965 March 16 - .
  • Navigational sighting requirements during an Apollo lunar landing mission - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC estimated the number of navigational sightings that Apollo crewmen would have to make during a lunar landing mission:

    • Translunar coast
      1. four maneuvers to align the inertial measurement unit (IMU)
      2. 20 navigational sightings requiring 10 maneuvers
    • Transearth coast
      1. four maneuvers for IMU alignment
      2. 50 sightings, 25 maneuvers
    • Lunar orbit
      1. 10 maneuvers for IMU alignment
      2. 24 sightings, 24 maneuvers.
    (The Manned Space Flight Network was the primary source for navigational data during the coasting phases of the mission; and although the network could supply adequate data during the circumlunar phase as well, onboard capability must be maintained.)

1965 April 9 - .
  • Recommendation for an up-data system in the Apollo LEM during manned missions - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM; CSM Guidance; LM Guidance; LM Weight. Systems Engineering Division (SED) reviewed the Flight Operations Directorate's recommendation for an up-data system in the LEM during manned missions. (Currently the LEM's guidance computer received data either from the computer in the CSM or from MSC.) SED concluded that, because the equipment was not essential for mission success, an up-data system did not warrant the cost and weight penalties ($750,000 and 4.54 kg (10 lbs)) that it would entail.

1965 April 12 - .
  • MIT contract to design guidance and navigation equipment for Apollo spacecraft - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Summary: MSC awarded MIT a new $15,529,000 contract to design guidance and navigation equipment for Apollo spacecraft..

1965 October 7-14 - .
  • Beryllium posed a toxicological hazard to the crew of the Apollo CM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. MSC's Reliability and Quality Assurance Division reported in August that, because beryllium would corrode in the humid environment of the spacecraft's cabin, the metal thus posed a toxicological hazard to the crew of the CM. During subsequent meetings with the Health and Physics Group, and Guidance and Control and Structures and Mechanics Divisions, it was agreed that, because of crew safety, beryllium surfaces in the guidance and control system must be coated to protect the metal from the humid atmosphere inside the cabin of the spacecraft.

1966 March 28 - .
  • Cost problems of the Apollo contract with General Motors' AC Electronics Division - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. Apollo Program Director Samuel C. Phillips discussed cost problems of the contract with General Motors' AC Electronics Division, in a memo to NASA Associate Administrator for Manned Space Flight George E. Mueller. One of the problems was late design releases from Massachusetts Institute of Technology to AC Electronics, resulting in an increase of $2.7 million. Phillips also pointed out that computer problems at Raytheon Corp. had increased the program cost by $6.7 million, added that many of these problems had their origins in the MIT design, and listed seven of the most significant technical problems. Phillips stated that MSC in conjunction with AC Electronics had taken several positive steps:

    1. to establish a factory test method review board to review all procedures encompassing fabrication of the computer in the manufacturing process;
    2. to schedule 100-percent audit of all hardware in fabrication; and
    3. to increase the AC Electronics resident technical staff at the Raytheon plant.

1966 May 19 - .
  • Problem of potential Apollo mission aborts - . Nation: USA. Related Persons: Kraft. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. E. E. Christensen, NASA OMSF Director of Mission Operations, in a letter to Christopher C. Kraft, Jr., MSC, said he was certain the problem of potential mission abort was receiving considerable attention within the Flight Operations Directorate. The resulting early development of related mission rules should provide other mission activities with adequate planning information for design, engineering, procedural, and training decisions. Christensen requested that development of medical mission rules be given emphasis in planning, to minimize the necessity for late modification of spacecraft telemetry systems, on-board instrumentation, ground-based data-processing schemes, and training schedules.

1966 June 23 - .
  • Two-burn Apollo lunar orbit deboost technique proposed - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance; CSM Recovery. A memorandum for the file, prepared by J. S. Dudek of Bellcomm, Inc., proposed a two-burn deboost technique that required establishing an initial lunar parking orbit and, after a coast phase, performing an added plane change to attain the final lunar parking orbit. The two-burn deboost technique would make a much larger lunar area accessible than that provided by the existing Apollo mission profile, which used a single burn to place the CSM and LM directly in a circular lunar parking orbit over the landing site and would permit accessibility to only a bow-tie shaped area approximately centered about the lunar equator. On August 1, the memo was forwarded to Apollo Program Director Samuel C. Phillips, stating that the trajectory modification would increase the accessible lunar area about threefold. The note to Phillips from R. L. Wagner stated that discussions had been held with MSC and it appeared that the flight programs as planned at the time could handle the modified mission.

1966 July 29 - .
  • Apollo Computer Design Review - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. In response to a request from Apollo Program Director Samuel C. Phillips, Bellcomm, Inc., prepared a memorandum on the major concerns resulting from its review of the AC Electronics report on the Apollo Computer Design Review. In a transmittal note to Phillips, I. M. Ross said, "We have discussed these items with MSC. It is possible, however, that (Robert) Duncan and (Joseph) Shea have not been made aware of these problems." The Bellcomm memorandum for file, prepared by J. J. Rocchio, reported that in late February 1966 MSC had authorized AC Electronics Division (ACED) to initiate a complete design review of the Apollo guidance computer to ensure adequate performance during the lunar landing mission. A June 8 ACED report presented findings and included Massachusetts Institute of Technology comments on the findings. In addition to recommending a number of specific design changes, the report identified a number of areas which warranted further review. MSC authorized ACED to perform necessary additional reviews to eliminate all indeterminate design analyses and to resolve any discrepancies between the ACED and MIT positions. At the time Bellcomm prepared the memo many of the problem areas had been or were in process of being satisfactorily resolved. However, several still remained:

    1. MSC had not had the opportunity to review an approved version of the final test method for the Block II/LM computer and as a result there was no official acceptance test for computers at that point, although the first of the flight-worthy computers had left the factory and the second was in final test at the factory.
    2. The Design Review Report classified the timing margin of the Block II computer as indeterminate, since the team was unable to make a detailed timing analysis in the allotted time.
    3. Both Block I and Block II Apollo guidance computer programs had experienced serious problems with parts qualification and with obtaining semiconductor devices which could pass the flight processing specifications.
    4. The lack of adequate documentation to support the Block II computer and its design was cited "as perhaps the most significant fault uncovered" by the design review team.

1966 October 7 - .
  • Apollo AS-202 impact error analzyed - . Nation: USA. Related Persons: Mueller. Program: Apollo. Spacecraft: Apollo CSM; CSM Guidance. In a memorandum to the NASA Deputy Administrator, Associate Administrator for Manned Space Flight George E. Mueller commented on the AS-202 impact error. Mueller said the trajectory of the August 25 AS-202 mission was essentially as planned except that the command module touched down about 370 kilometers short of the planned impact point. Additional Details: here....

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