LM Communications (original) (raw)

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LM Communications

Part of Apollo Spacecraft Systems Development Diaries

LM Communications Development Diary - The lunar module had to communicate with the CSM, the astronauts on the surface of the moon and Houston - while being nested in the S-IVB stage, in flight around the moon, and on the surface. No wonder there were constant problems and compromises....

1962 August 14 - .

• LEM added to Apollo CSM Statement of Work - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM ECS, LM Guidance, LM Hatch, LM Source Selection.
  The NAA spacecraft Statement of Work was revised to include the requirements for the lunar excursion module (LEM) as well as other modifications. The LEM requirements were identical with those given in the LEM Development Statement of Work of July 24.
  The command module (CM) would now be required to provide the crew with a one-day habitable environment and a survival environment for one week after touching down on land or water. In case of a landing at sea, the CM should be able to recover from any attitude and float upright with egress hatches free of water. Additional Details: here....

1962 September 5 - .

• Study of Apollo docking and crew transfer - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Hatch, LM Communications, LM ECS, LM Hatch, LM Source Selection.
  Apollo Spacecraft Project Office requested NAA to perform a study of command module-lunar excursion module (CM-LEM) docking and crew transfer operations and recommend a preferred mode, establish docking design criteria, and define the CM-LEM interface. Both translunar and lunar orbital docking maneuvers were to be considered. The docking concept finally selected would satisfy the requirements of minimum weight, design and functional simplicity, maximum docking reliability, minimum docking time, and maximum visibility.
  The mission constraints to be used for this study were :
  • The first docking maneuver would take place as soon after S-IVB burnout as possible and hard docking would be within 30 minutes after burnout.
  • The docking methods to be investigated would include but not be limited to free fly-around, tethered fly-around, and mechanical repositioning.
  • The S-IVB would be stabilized for four hours after injection.
  • There would be no CM airlock. Extravehicular access techniques through the LEM would be evaluated to determine the usefulness of a LEM airlock.
  • A crewman would not be stationed in the tunnel during docking unless it could be shown that his field of vision, maneuverability, and communication capability would substantially contribute to the ease and reliability of the docking maneuver.
  • An open-hatch, unpressurized CM docking approach would not be considered.
  • The relative merit of using the CM environmental control system to provide initial pressurization of the LEM instead of the LEM environmental control system would be investigated.

1962 November 27 - .

• Sketch of the space suit assembly to be worn on the lunar surface - . Nation: USA. Program: Apollo. Spacecraft: A7L, LM Communications, LM ECS.
  MSC released a sketch of the space suit assembly to be worn on the lunar surface. It included a portable life support system which would supply oxygen and pressurization and would control temperature, humidity, and air contaminants. The suit would protect the astronaut against solar radiation and extreme temperatures. The helmet faceplate would shield him against solar glare and would be defrosted for good visibility at very low temperatures. An emergency oxygen supply was also part of the assembly.
  Four days earlier, MSC had added specifications for an extravehicular suit communications and telemetry (EVSCT) system to the space suit contract with Hamilton Standard Division of United Aircraft Corporation. The EVSCT system included equipment for three major operations:
  1. Full two-way voice communication between two astronauts on the lunar surface, using the transceivers in the LEM and CM as relay stations.
  2. Redundant one-way voice communication capability between any number of suited astronauts.
  3. Telemetry of physiological and suit environmental data to the LEM or CM for relay to earth via the S- band link.
     (The EVSCT contract was awarded to International Telephone and Telegraph (ITT) Corporation's Kellogg Division).

1963 March - .

• Preliminary design specifications for the Apollo LEM communications system - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  Grumman met with representatives of North American, Collins Radio Company, and Motorola, Inc., to discuss common usage and preliminary design specifications for the LEM communications system. These discussions led to a simpler design for the S-band receiver and to modifications to the S-band transmitter (required because of North American's design approach).

1963 April - .

• Grumman studies on common usage of Apollo CSM/LM communications - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Television, LM Communications, LM Television. Grumman reported to MSC the results of studies on common usage of communications. Television cameras for the two spacecraft would be identical; the LEM transponder would be as similar as possible to that in the CSM..

1963 May 22 - .

• Grumman representatives met with the Apollo ASPO Electrical Systems Panel (ESP) - . Nation: USA. Program: Apollo. Spacecraft: A7L, Apollo LM, CSM Communications, LM Communications.
  Grumman representatives met with the ASPO Electrical Systems Panel (ESP). From ESP, the contractor learned that the communications link would handle voice only. Transmission of physiological and space suit data from the LEM to the CM was no longer required. VHF reception of this data and S-band transmission to ground stations was still necessary. In addition, Grumman was asked to study the feasibility of a backup voice transmitter for communications with crewmen on the lunar surface should the main VHF transmitter fail.

1963 May 23 - .

• Apollo LEM and CSM to incorporate phase-coherent S-band transponders - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM SPS, LM Communications.
  NASA Headquarters, MSC, Jet Propulsion Laboratory, MSFC, North American, and Grumman agreed that the LEM and CSM would incorporate phase-coherent S-band transponders. (The S-band system provides a variety of communications services. Being phase-coherent meant that it could also provide Mission Control Center with information about the vehicle's velocity and position, and thus was a means of tracking the spacecraft.) Each would have its own allocated frequencies and would be compatible with Deep Space Instrumentation Facilities.

1963 June 10 - .

• Up-data link (UDL) to be included on the Apollo LEM - . Nation: USA. Program: Apollo. Spacecraft: Apollo CSM, CSM Communications, LM Communications.
  Christopher C. Kraft, Jr., of the MSC Flight Operations Division, urged that an up-data link (UDL) be included on the LEM. In general, the UDL would function when a great deal of data had to be transmitted during a time-critical phase. It would also permit utilization of the ground operational support system as a relay station for the transmission of data between the CM and LEM. In case of power failure aboard the LEM, the UDL could start the computer faster and more reliably than a manual voice link, and it could be used to resume synchronization in the computer timing system.

1963 June 28 - .

• RCA named as subcontractor for Apollo LEM electronics subsystems and for engineering support - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Guidance.
  NASA announced its concurrence in Grumman's selection of RCA as subcontractor for the LEM electronics subsystems and for engineering support. Under the $40 million contract, RCA was responsible for five LEM subsystem areas: systems engineering support, communications, radar, inflight testing, and ground support. RCA would also fabricate electronic components of the LEM stabilization and control system. (Engineers and scientists from RCA had been working at Grumman on specific projects since February.)

1963 Week of August 22-29 - .

• Ad Hoc Rendezvous Working Group formed - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Communications, LM Communications, LM Guidance. An Ad Hoc Rendezvous Working Group was formed at MSC to study the possibility of substituting a unified S-band system for the rendezvous X-band radar on the LEM and CSM..

1963 October 23-30 - .

• Contract to Hughes for a study of backup high gain antenna for Apollo LEM lunar surface equipment - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications. MSC Instrumentation and Electronic Systems Division awarded a $50,000 contract to the Hughes Aircraft Company for a study of backup high gain directable antennas for the LEM lunar surface equipment..

1963 November 8 - .

• Go-ahead to RCA to develop the Apollo LEM radar - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Guidance.
  Grumman issued a go-ahead to RCA to develop the LEM radar. Negotiations on the $23.461 million cost- plus-fixed-fee contract were completed on December 10. Areas yet to be negotiated between the two companies were LEM communications, inflight test, ground support, and parts of the stabilization and control systems.

1964 February 25 - .

• Contract on the Apollo LEM communications subsystem - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications. Grumman and RCA signed a contract on the LEM communications subsystem..

1964 April 2-9 - .

• Revisions to Apollo's communications requirements - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Guidance.
  The MSC Operations Planning Division (OPD) reviewed recent revisions by OMSF to Apollo's communications requirements:
  • Elimination of the requirement for continuous tracking of the spacecraft during translunar injection
  • Sequential rather than simultaneous transmission of data from the ground to the two spacecraft (to be compatible with the Manned Space Flight Network)
  • A five-kilometer (three-nautical-mile) communications range on the lunar surface (to be compatible with the design of the portable life support system)
  • Elimination of the requirement for direct transmission to the CSM from an extravehicular astronaut; instead, such transmission would be relayed via the LEM.
    Thus were resolved, OPD reported, a number of conflicting items (i.e., incompatibilities between OMSF's requirements and the capabilities of the two spacecraft). Two other items that OMSF made into firm requirements were already compatible with the design of the spacecraft:
  1. A radar in the CSM capable of tracking the LEM (provided the LEM had a compatible transponder)
  2. Three-way communications between an astronaut on the moon, his fellow crewman inside the LEM, and with mission control.

1964 October 8 - .

• Contract for the Apollo LEM attitude translation control assembly - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Guidance, LM RCS.
  Radio Corporation of America's (RCA) Aerospace Systems Division received a 9 million contract from Grumman for the LEM attitude translation control assembly (ATCA). The ATCA, a device to maintain the spacecraft's attitude, would fire the reaction control system motors in response to signals from the primary guidance system.

1964 October 15 - .

• Joint MSC-Grumman meeting on Apollo LEM communications - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  A number of outstanding points were resolved at a joint MSC-Grumman meeting on LEM communications. Most significant, the VHF key mode was deleted, and it was decided that, during rendezvous, voice links must have priority over all other VHF transmissions. Further, the echo feature of the current configuration (i.e., voice sent to the LEM by the ground operational support system, then relayed back via the S-band link) was undesirable.

1964 November 5-12 - .

• Coverage requirements for Apollo LEM's S-band radio reviewed - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  Engineers from Grumman and the MSC Instrumentation and Electronics Systems Division (IESD) reviewed the coverage requirements for the LEM's S-band radio and the incompatibility of those requirements with the present location of the steerable antenna. Most observers felt that a deployable boom was the only feasible solution. The two groups therefore recommended that IESD verify with ASPO the S-band coverage requirements and that Grumman analyze the design effects of such a boom. In the meantime, Dalmo-Victor, the antenna vendor, should continue its design effort on the basis of the current location.

1964 December 8 - .

• Communications during LEM and Apollo CSM rendezvous - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Communications, LM Communications.
  Representatives of MSC's Information and Electronic Systems Division, Flight Operations Division, Flight Crew Operations Division, Guidance and Control Division, Astronaut Office, and ASPO, Goddard Space Flight Center, and Bellcomm, Inc., met to discuss communications during LEM and CSM rendezvous.
  Capability of the Manned Space Flight Network (MSFN) to provide data for rendezvous was studied. Aaron Cohen of ASPO stated sufficient data could be collected, processed, and transmitted via MSFN to the LEM to achieve rendezvous. Dr. F. O. Vonbun of Goddard showed that MSFN data did little to improve data already available in the LEM before launch. Although five tracking stations would communicate with the LEM during ascent and the first 10 minutes of orbit, there would be only a slight improvement in spacecraft position and motion data over the data already contained in the LEM computer. No decision was made concerning the MSFN's capability.
  Alternate rendezvous methods were discussed.

1965 January 12 - .

• Apollo LEM VHF communications requirements reviewed - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  MSC evaluated the VHF communications requirements and determined that there was no requirement for the LEM to communicate simultaneously over VHF with:
  1. the CSM in lunar orbit
  2. an extravehicular astronaut on the lunar surface.
     There also was no requirement for the CSM to communicate simultaneously over VHF with:
  3. an extravehicular astronaut
  4. an astronaut in the LEM.
     Grumman and North American were advised that voice communications during this mission phase would be maintained by the unified S-band equipment via the Manned Space Flight Network relay.

1965 January 18 - .

• Alternates considered for Apollo S-band high-gain antenna - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Block II, LM Communications, LM Guidance.
  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.

1965 January 22 - .

• Apollo LEM adapter panels might interfere with radio communications - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  The MSC-MSFC Mechanical Integration Panel discussed the possibility that, when deployed, the LEM adapter panels might interfere with radio communications via the S-band high-gain antenna. On earth-orbital missions, the panel found, the S-band antenna would be rendere useless. They recommended that MSC's Instrumentation and Electronic Systems Division investigate alternative modes for communications during the transposition and docking phase of the flight. During lunar missions, on the other hand, the panel found that, with panels deployed at a 45 degree angle, the high-gain antenna could be used as early as 15 minutes after translunar injection. Spacecraft-to-ground communications during transposition and docking could thus be available and manual tracking would not be needed. North American was informed that the high-gain antenna would be used during this maneuver, and was directed to fix the panel deployment angle for all Block II spacecraft at 45 degrees.

1965 January 25 - .

• Dalmo-Victor freezes the design of the Apollo LEM S-band antenna - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications. Dalmo-Victor, vendor of the LEM S-band antenna, was given firm requirements for tracking and coverage, thus enabling the company to freeze the antenna design..

1965 February 16 - .

• Specialty areas for 13 astronauts not assigned to Gemini - . Nation: USA. Related Persons: Aldrin, Anders, Bassett, Bean, Cernan, Chaffee, Collins, Cunningham, Eisele, Freeman, Gordon, Schweickart, Scott, Williams, Clifton. Program: Apollo. Spacecraft: Apollo LM, CSM ECS, LM Communications, LM ECS, LM Guidance.
  MSC announced a realignment of specialty areas for the 13 astronauts not assigned to forthcoming Gemini missions (GT 3 through 5) or to strictly administrative positions:
  Operations and Training
  Edwin E. Aldrin, branch chief - mission planning
  Charles A. Bassett - operations handbooks, training, and simulators
  Alan L. Bean - recovery systems
  Michael Collins - pressure suits and extravehicular activity
  David R. Scott - mission planning and guidance and navigation
  Clifton C. Williams - range operations, deep space instrumentation, and crew safety.
  Project Apollo
  Richard F. Gordon, branch chief - overall astronaut activities in Apollo area and liaison for CSM development
  Donn F. Eisele - CSM and LEM
  William A. Anders - environmental control system and radiation and thermal systems
  Eugene A. Cernan - boosters, spacecraft propulsion, and the Agena stage
  Roger B. Chaffee - communications, flight controls, and docking
  R. Walter Cunningham - electrical and sequential systems and non-flight experiments
  Russell L. Schweickart - in-flight experiments and future programs.

1965 February 19 - . Launch Vehicle: Saturn V.

• Deployment angle of the Apollo adapter panels changed - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Block II, LM Communications.
  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.

1965 March 8 - .

• Passive thermal control of all-battery Apollo LEM doubtful - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Electrical.
  Preliminary investigation by Grumman indicated that, with an all-battery LEM, passive thermal control of the spacecraft was doubtful. (And this analysis did not include the scientific experiments package, which, with its radioisotope generator, only increased the problem. Grumman and MSC Structures and Mechanics Division engineers were investigating alternate locations for the batteries and modifications to the surface coatings of the spacecraft as possible solutions.

1965 March 15 - .

• Radioisotope power supply for the Apollo scientific equipment - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Electrical.
  In November 1964, MSC asked Grumman to conduct a study on the feasibility of carrying a radioisotope power supply as part of the LEM's scientific equipment. The subsequent decision to use batteries in the LEM power system caused an additional heat load in the descent stage. Therefore, MSC requested the contractor to continue the study using the following ground rules: consider the radioisotope power supply a requirement for the purpose of preliminary design efforts on descent stage configuration; determine impact of the radioisotope power supply - in particular its effect on passive thermal control of the descent stage; and specify which characteristics would be acceptable if any existing characteristics of the radioisotope power supply had an adverse effect. The radioisotope power was used only to supply power for the descent stage.

1965 March 31 - . Launch Vehicle: Saturn I.

• Apollo LEMs 1, 2, and 3 to have remote command of the transponder feature - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  MSC requested that Grumman incorporate in the command list for LEMs 1, 2, and 3 the capability for turning the LEM transponder off and on by real-time radio command from the Manned Space Flight Network. Necessity for capability of radio command for turning the LEM transponder on after LEM separation resulted from ASPO's decision that the LEM and Saturn instrument unit S-band transponders would use the same transmission and reception frequencies.

1965 April 7 - .

• A LEM/Apollo CSM interface meeting uncovered a number of design problems - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM RCS, LM Communications, LM RCS.
  A LEM/CSM interface meeting uncovered a number of design problems and referred them to the Systems Engineering Division (SED) for evaluation: the requirement for ground verification of panel deployment prior to LEM withdrawal; the requirement for panel deployment in earth orbit during the SA-206 flight; the absence of a backup to the command sequencer for jettisoning the CSM (Flight Projects Division (FPD) urged such a backup signal); and Grumman's opposition to a communications link with the LEM during withdrawal of the spacecraft (FPD felt that such a link was needed through verification of reaction control system ignition). SED's recommendations on these issues were anticipated by April 22.

1965 May 5 - .

• Communications between the Apollo CSM, LEM, and extravehicular astronauts were reviewed - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Block II, LM Communications, LM Guidance, LM Hatch.
  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.

1965 May 17 - .

• MSC to participate in Apollo LEM manned environmental control system tests - . Nation: USA. Related Persons: Anders. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM ECS.
  MSC informed Grumman it believed it would be beneficial to the LEM development program for MSC to participate in the manned environmental control system tests to be conducted in Grumman's Internal Environment Simulator. The following individuals were suggested to participate: Astronaut William A. Anders or an alternate to act as a test crewman for one or more manned runs; D. Owen Goons or an alternate to act as a medical monitor for the aforementioned astronaut; and John W. O'Neill or an alternate to monitor voice communications during the test and record astronaut comments.

1965 May 18-20 - .

• First design review on the S-band transponder for the Apollo LEM - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  Representatives from Motorola, RCA, Grumman, and MSC held the first design review on the S-band transponder for the LEM. Several areas were pointed out in which the equipment was deficient. Motorola was incorporating improved circuitry to ensure that the transponder met specifications.

1965 May - .

• One-third scale model test of the Apollo LEM's antenna field - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications. Using one-third scale models, Grumman tested the LEM's antenna field at the extremes of the frequency range. Data evaluation showed that the range was adequate; errors were well within expected values..

1965 June 12 - .

• Communications systems specified for the first three R&D Apollo LEMs - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  Apollo Program Director Samuel C. Phillips listed the RE communications systems envisioned by NASA Headquarters on the first three R&D LEMs and requested ASPO Manager Joseph F. Shea's comments.
  The first three LEMs (LEM-1, LEM-2, and LEM-3) would be equipped with communications equipment in addition to that required in the LEM for lunar missions to provide:
  1. transmission of required engineering (R&D) data;
  2. redundant operational telemetry;
  3. updating of spacecraft equipment via an up-data command link; and
  4. redundant tracking capability.
     The LEM R&D communications system was essentially independent from the operational communications systems. It would be housed primarily in the equipment bay (which on operational flights would house the scientific payload equipment).

1965 June 28 - .

• Apollo LEM communications problem - . Nation: USA. Related Persons: Maynard. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Descent Propulsion.
  Systems Engineering Division chief, Owen E. Maynard, reported to the Instrumentation and Electronic Systems Division (IESD) the results of a study on a LEM communications problem (undertaken by his own group at IESD's request). During phases of powered descent to certain landing sites (those in excess of 20 degrees east or west longitude), the structure of the spacecraft would block the steerable antenna's line of sight with the earth. Communications with the ground would therefore be lost. Maynard concurred with IESD that the problem could best be solved by rotating the LEM about its thrust axis.

1965 July 21 - .

• Apollo experiments package would be left on the moon - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Weight.
  MSC officially notified Grumman that, as part of the Apollo scientific program, an experiments package would be left on the moon by the crewmen of the LEM. The Center outlined weight and storage requirements for the package, which would be stored in the descent stage of the vehicle along with the lunar geological equipment. And MSC emphasized the need for dissipating waste heat given off by the system's radioisotope generator. (The radioisotope generator was a firm requirement, despite the fear voiced by many scientists that the radiation it gave off would disrupt the experiments.)

1965 August 2 - .

• Plans to install Apollo Unified S-Band System equipment at Corpus Christi tracking station - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, CSM Television, LM Communications, LM Television.
  NASA announced plans to install Apollo Unified S-Band System equipment at its Corpus Christi, Tex., tracking station. The Unified S-Band equipment included a 9-m (30-ft) diameter parabolic antenna and would enable handling of seven different types of communications with two different vehicles, the CM and the LEM. The communications would: track the spacecraft; command its operations and confirm that the command had been executed; provide two-way voice conversation with three astronauts; keep a continuous check on the astronauts' health; make continuous checks on the spacecraft and its functions; supply a continuous flow of information from the Apollo onboard experiments; and transmit television of the astronauts and the exploration of the moon.

1965 September 24 - .

• Critical Design Review (CDR) of the Apollo LEM rescheduled - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Guidance.
  The Critical Design Review (CDR) of the LEM, tentatively planned during the week of September 27, 1965, at Grumman, was rescheduled as a series of reviews beginning in November 1965 and ending in January 1966. The schedule was to apply with five teams participating as follows: Structures and Propulsion, November 8-11, Team Captain: H. Byington; Communications, Instrumentation, and Electrical Power, December 6-9, Team Captain: W. Speier; Stabilization and Control, Navigation and Guidance, and Radar, January 10-13, Team Captain: A. Cohen; Crew Systems, January 10-13, Team Captain: J. Loftus; and Mission Compatibility and Operations, January 24-27, Team Captain: R. Battey.

1965 October 7-14 - .

• Apollo LEM's inflight VHF antenna might be used as a link to astronauts on the surface of the moon - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Weight.
  The Instrumentation and Electronic Systems Division (IESD) proposed that the LEM's inflight VHF antenna might be used as a link to astronauts on the surface of the moon as well. (LEM communications had to provide VHF contact with the crew outside the spacecraft at ranges up to three nautical miles. The VHF antenna, however, had been designed only for the flight portions of the mission, and to meet this communications requirement another antenna was being added to the LEM at a cost of between 1.36 and 2.26 kg (3 and 5 lbs).) IESD offered to study the coverage and range of the inflight antenna while on the lunar surface, and suggested that the three-mile range requirement might be relaxed. The additional VHF antenna might thereby be obviated.
  Also, IESD attended a preliminary design review at Autonetics on the signal conditioning equipment (SCE) for the Block II CSM. IESD concurred in several modifications to the Block I design (adding a redundant power supply; hermetic sealing of equipment; and repackaging to fit the equipment bay in Block II CMs). These changes reduced the SCE's weight from 22 to 19 kg (47.5 to 41 lbs) and, because of more efficient power supply, lowered its power consumption from 65 to 35 watts. North American was studying ways of perhaps lightening the SCE even further.

1966 March 17 - .

• Apollo time-critical aborts due to service propulsion system failure investigated - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM ECS.
  John D. Hodge, Chief of MSC's Flight Control Division, proposed that time-critical aborts in the event of a service propulsion system failure after translunar injection (TLI; i.e., insertion on a trajectory toward the moon) be investigated. Time-critical abort was defined as an abort occurring within 12 hours after TLI and requiring reentry in less than two days after the abort.
  He suggested that if an SPS failed the service module be jettisoned for a time-critical abort and both LEM propulsion systems be used for earth return, reducing the total time to return by approximately 60 hours. As an example, if the time of abort was 10 hours after translunar injection, he said, this method would require about 36 hours; if the SM were retained the return time would require about 96 hours.
  He added that the LEM/CM-only configuration should be studied for any constraints that would preclude initiating this kind of time-critical abort. Some of the factors to be considered should be:
  1. maximum time the LEM environmental control system could support two or three men on an earth return;
  2. maximum time the CM electrical system could support minimum power-up condition;
  3. time constraints on completely powering down the CM and using the LEM systems for support;
  4. effects on planned landing areas from an open loop reentry mode;
  5. stability of the LEM/CM configuration during the descent and ascent propulsion burns;
  6. total time to return using the descent propulsion system only or both the LEM's descent propulsion system and ascent propulsion system; and
  7. communications with Manned Space Flight Network required to support this abort.

1966 December 23 - .

• Responsibilities for Apollo LM descent stage scientific equipment - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Descent Propulsion, LM Landing Gear.
  Handling and installation responsibilities for the LM descent stage scientific equipment (SEQ) were defined in a letter from MSC to Grumman Aircraft Engineering Corp. The descent stage SEQ was composed of three basic packages:
  1. the Apollo Lunar Surface Experiments Package (ALSEP) compartment 1, which included the ALSEP central station and associated lunar surface experiments;
  2. ALSEP compartment 2, composed of the radioisotope thermoelectric generator (RTG) and Apollo lunar surface drill (ALSD); and
  3. the RTG fuel cask, thermal shield, mount and RTG fuel element.
     The following definition of responsibility for handling and installation had been derived:
  4. The SEQ would be installed in the LM descent stage while the LM was in the LM landing gear installation stand before LM-SLA mating, with the exception of the RTG fuel cask, thermal shield, mount and fuel element, and the ALSD.
  5. The RTG fuel cask, thermal shield, mount and fuel element and the ALSD would be installed in the LM descent stage during prelaunch activities at the launch site.
  6. Grumman would be responsible for SEQ installation with the exception of the RTG fuel element. The ALSEP contractor, Bendix Aerospace Systems Division, would provide the installation procedure and associated equipment. Bendix would also observe the installation operation and NASA would both observe and inspect it.
  7. The Atomic Energy Commission (AEC) would be responsible for handling and installing the RTG fuel element. Bendix would provide procedures and associated equipment. Grumman and NASA would observe and inspect this operation. If for any reason the RTG fuel element was required to be removed during prelaunch operations, the AEC would be responsible for the activity. Removal procedures would be provided by Bendix. MSC requested that Grumman's planned LM activities at Kennedy Space Center reflect these points of definition.

1967 June 6 - .

• Bendix demonstrated boom to remove Apollo Lunar Surface Experiments Package (ALSEP) the LM - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM Weight.
  Bendix Corp. demonstrated the operation of a sliding boom concept to prove that the Apollo Lunar Surface Experiments Package (ALSEP) could be removed from the LM at various attitudes. MSC representatives viewing the demonstration at Ann Arbor, Mich., were Aaron Cohen, Don Weissman, Paul Gerke, Don Lind, and Harrison Schmitt. Cohen reported that the mockup was crude but indicated that the concept was satisfactory to both Grumman and NASAL Design refinement, qualification, and effect on LM structure would have to be looked into. It was believed an additional seven kilograms of weight would be added to the LM descent stage. Two interface problems were defined at the meeting:
  1. Bendix and Grumman required maximum and minimum attitude position for the LM to complete the design of ALSEP handling equipment.
  2. Both Grumman and Bendix required temperature criteria for the outer shield of the cask, which would contain radioactive material.

1967 September 29 - .

• Apollo spacecraft weight changes - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications, LM ECS, LM Guidance, LM Hatch.
  Because of many questions asked about spacecraft weight changes in the spacecraft redefinition, ASPO Manager George M. Low prepared a memo for the record, indicating weights as follows:
  Lunar Module Significant Weight Changes Lunar module injected weight status March 1, 1967 (ascent and descent less propellant) - 4039.6 kg
  • Material substitution +23.1;
  • decrease clamps and potting, -4.5;
  • government furnished equipment changes (pressure garment assembly, portable life support system, oxygen purge system), +68;
  • plume heating and "fire-in-the-hole" protection, +59.8;
  • redesign umbilical hoses, +2.2;
  • revised oxygen and water requirements, +19.5;
  • provision for ALSEP removal, +11.3;
  • increasing crack resistance of webs, +13.6;
  • additional wiring to provide redundant circuits, +4.9;
  • fuel cask and support increase, +14.9;
  • guidance and navigation equipment, +3.1;
  • instrumentation, +9.9;
  • communications, +1.8;
  • miscellaneous changes, +2.2.
    Net change from March to September was +230.4 kg.
    Lunar module injected weight status September 22, 1967 - 4270.0 kg
    Command Module Significant Weight Changes Command module injected weight status March 1, 1967 - 5246.7 kg
  • New hatch, +114.7;
  • environmental control system and weight management system changes, +103.4;
  • instrumentation and electrical power, +48;
  • wiring and tubing protection, +44.4;
  • crew compartment materials and crew equipment, +101.6;
  • forward heatshield separation, +13.6;
  • earth landing system (larger drogues), +21.7;
  • miscellaneous structural changes, +26.7;
  • ballast for lift-over-drag ratio of 0.35, +175;
  • other, +19.5.
  • Reductions - transfer of portable life support system to LM,-31.2;
  • reduced ballast for lift-over-drag ratio of 0.28, -142.8;
  • other MSC weight reductions, -61.6.
    Net change from March to September was +433.1 kg.
    Command module injected weight status September 22, 1967 - 5679.8 kg

1968 February 20 - .

• Communications during Apollo exploration of the lunar surface - . Nation: USA. Program: Apollo. Spacecraft: Apollo LM, LM Communications.
  Reflecting the climate of scientific thinking at his Center, MSC Director Robert R. Gilruth responded to inquiries from Homer E. Newell, NASA Associate Administrator, concerning vocal communications during exploration of the lunar surface. While he termed continuous talking undesirable, Gilruth stated an astronaut's running comment would in effect form a set of field notes that a geologist might ordinarily keep during a field exercise. This normal vocal narrative, he told Newell, would keep ground control informed of mission progress and would ensure a maximum scientific return from the flight.

1969 December 1 - .

• Requirement for a simple lightweight Apollo lunar roving vehicle guidance and navigation system - . Nation: USA. Program: Apollo. Flight: Apollo 12. Spacecraft: Apollo LRV, LM Communications, LM Guidance, LM Weight.
  The MSC Flight Crew Operations Directorate submitted its requirement for a simple lightweight Rover (lunar roving vehicle) guidance and navigation system that would provide the following displayed information to the crew: vehicle heading and heading to the LM, speed in kilometers per hour, total distance traveled in kilometers, and distance to the LM. Additional Details: here....

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