Apollo LM Credit - © Mark Wade

Following the decision to use the lunar orbit rendezvous method to get to the moon, Grumman received the contract to develop the lunar module, which would take the first men to the surface to the moon. If funding had been available, modified lunar modules (dubbed LM Taxi, LM Shelter, and LM Truck) would have been used to set up the first lunar bases.

See Apollo Spacecraft Systems Development Diaries for details on development of the LM by subsystem.

Unit Cost $: 50.000 million. Crew Size: 2. Length: 6.37 m (20.89 ft). Maximum Diameter: 4.27 m (14.00 ft). Span: 9.07 m (29.75 ft). Habitable Volume: 6.65 m3. Mass: 14,696 kg (32,399 lb). Main Engine: TR-201. Main Engine Thrust: 44.041 kN (9,901 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 10,523 kg (23,199 lb). Main Engine Isp: 311 sec. Spacecraft delta v: 4,700 m/s (15,400 ft/sec). Electrical System: Batteries. Electric System: 50.00 kWh.

• Apollo LM AS.  Other Designations: Ascent Stage. Part of: Apollo LM. Class: Manned. Type: Spacecraft Module.

  Crew Size: 2. Length: 3.54 m (11.61 ft). Basic Diameter: 4.27 m (14.00 ft). Maximum Diameter: 4.27 m (14.00 ft). Habitable Volume: 6.65 m3. Mass: 4,547 kg (10,024 lb). Crew mass: 144 kg (317 lb). RCS Coarse No x Thrust: 16 x 440 N. RCS Propellants: N2O4/UDMH. RCS Isp: 290 sec. Main Engine Thrust: 15.572 kN (3,501 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 2,358 kg (5,198 lb). Main Engine Isp: 311 sec. Spacecraft delta v: 2,220 m/s (7,280 ft/sec). Electrical System: Batteries. Electric System: 17.00 kWh. Battery: 800.00 Ah.

• Apollo LM DS.  Other Designations: Descent Stage. Part of: Apollo LM. Class: Manned. Type: Spacecraft Module.

  Length: 2.83 m (9.28 ft). Basic Diameter: 4.21 m (13.81 ft). Maximum Diameter: 9.37 m (30.74 ft). Mass: 10,149 kg (22,374 lb). Main Engine Thrust: 44.041 kN (9,901 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 8,165 kg (18,000 lb). Main Engine Isp: 311 sec. Spacecraft delta v: 2,470 m/s (8,100 ft/sec). Electrical System: Batteries. Electric System: 33.00 kWh. Battery: 1,600.00 Ah.

• 1959 April 7 - Research into rendezvous techniques - Program: Apollo.
  NASA Administrator T. Keith Glennan requested $3 million for research into rendezvous techniques as part of the NASA budget for Fiscal Year 1960. In subsequent hearings, DeMarquis D. Wyatt, Assistant to the NASA Director of Space Flight Development, explained that these funds would be used to resolve certain key problems in making space rendezvous practical. Among these were the establishment of referencing methods for fixing the relative positions of two vehicles in space; the development of accurate, lightweight target-acquisition equipment to enable the supply craft to locate the space station; the development of very accurate guidance and control systems to permit precisely determined flight paths; and the development of sources of controlled power.

• 1959 December 8 - Configurations for manned lunar landing by direct ascent - Program: Apollo.
  Several possible configurations for a manned lunar landing by direct ascent being studied at the Lewis Research Center were described to the Research Steering Committee by Seymour C. Himmel. A six-stage launch vehicle would be required, the first three stages to boost the spacecraft to orbital speed, the fourth to attain escape speed, the fifth for lunar landing, and the sixth for lunar escape with a 10,000-pound return vehicle. One representative configuration had an overall height of 320 feet. H. H. Koelle of the Army Ballistic Missile Agency argued that orbital assembly or refueling in orbit (earth orbit rendezvous) was more flexible, more straightforward, and easier than the direct ascent approach. Bruce T. Lundin of the Lewis Research Center felt that refueling in orbit presented formidable problems since handling liquid hydrogen on the ground was still not satisfactory. Lewis was working on handling cryogenic fuels in space.

• 1960 January 30 - Manned lunar landing and return (MALLAR) - Program: Apollo.
  The Chance Vought Corporation completed a company-funded, independent, classified study on manned lunar landing and return (MALLAR), under the supervision of Thomas E. Dolan. Booster limitations indicated that earth orbit rendezvous would be necessary. A variety of lunar missions were described, including a two-man, 14-day lunar landing and return. This mission called for an entry vehicle of 6,600 pounds, a mission module of 9,000 pounds, and a lunar landing module of 27,000 pounds. It incorporated the idea of lunar orbit rendezvous though not specifically by name.

• 1960 March 21 - Chance Vought study of the lunar orbit rendezvous method - Program: Apollo.
  Thomas E. Dolan of the Chance Vought Corporation prepared a company-funded design study of the lunar orbit rendezvous method for accomplishing the lunar landing mission.

• 1960 April 5 - Houbolt paper on rendezvous in space with minimum expenditure of fuel - Program: Apollo.
  John C. Houbolt of the Langley Research Center presented a paper at the National Aeronautical Meeting of the Society of Automotive Engineers in New York City in which the problems of rendezvous in space with the minimum expenditure of fuel were considered. Additional Details: Houbolt paper on rendezvous in space with minimum expenditure of fuel.

• 1960 April 30 - MIT Report on space guidance and control design - Program: Apollo.
  A study report was issued by the MIT Instrumentation Laboratory on guidance and control design for a variety of space missions. This report, approved by C. Stark Draper, Director of the Laboratory, showed that a vehicle, manned or unmanned, could have significant onboard navigation and guidance capability.

• 1960 May 5 - STG and Grumman discuss advanced spacecraft programs - Program: Apollo.
  Robcrt R. Gilruth, Paul E. Purser, James A. Chamberlin, Maxime A. Faget, and H. Kurt Strass of STG met with a group from the Grumman Aircraft Engineering Corporation to discuss advanced spacecraft programs. Grumman had been working on guidance requirements for circumlunar flights under the sponsorship of the Navy and presented Strass with a report of this work.

• 1960 October 17 - Formation of a working group on the manned lunar landing program - Program: Apollo.
  In a memorandum to Abe Silverstein, Director of NASA's Office of Space Flight Programs, George M. Low, Chief of Manned Space Flight, described the formation of a working group on the manned lunar landing program: "It has become increasingly apparent that a preliminary program for manned lunar landings should be formulated. This is necessary in order to provide a proper justification for Apollo, and to place Apollo schedules and technical plans on a firmer foundation.

  "In order to prepare such a program, I have formed a small working group, consisting of Eldon Hall, Oran Nicks, John Disher, and myself. This group will endeavor to establish ground rules for manned lunar landing missions; to determine reasonable spacecraft weights; to specify launch vehicle requirements; and to prepare an integrated development plan, including the spacecraft, lunar landing and takeoff system, and launch vehicles. This plan should include a time-phasing and funding picture, and should identify areas requiring early studies by field organizations."

• 1960 December 10 - Lunar orbit method of accomplishing the lunar landing mission - Program: Apollo.
  Representatives of the Langley Research Center briefed members of STG on the lunar orbit method of accomplishing the lunar landing mission.

• 1960 December 14 - Seamans briefed on the lunar orbit rendezvous method - Program: Apollo.
  Associate Administrator of NASA Robert C. Seamans, Jr., and his staff were briefed by Langley Research Center personnel on the rendezvous method as it related to the national space program. Clinton E. Brown presented an analysis made by himself and Ralph W. Stone, Jr., describing the general operational concept of lunar orbit rendezvous for the manned lunar landing. The advantages of this plan in contrast with the earth orbit rendezvous method, especially in reducing launch vehicle requirements, were illustrated. Others discussing the rendezvous were John C. Houbolt, John D. Bird, and Max C. Kurbjun.

• 1960 December 29 - Grumman began work on a lunar orbit rendezvous study - Program: Apollo.
  The Grumman Aircraft Engineering Corporation began work on a company- funded lunar orbit rendezvous feasibility study.

• 1961 January 5 - Manned lunar landing discussed with Space Exploration Program Council - Program: Apollo.
  During a meeting of the Space Exploration Program Council at NASA Headquarters, the subject of a manned lunar landing was discussed. Following presentations on earth orbit rendezvous (Wernher von Braun, Director of Marshall Space Flight Center), lunar orbit rendezvous (John C. Houbolt of Langley Research Center), and direct ascent (Melvyn Savage of NASA Headquarters), the Council decided that NASA should not follow any one of these specific approaches, but should proceed on a broad base to afford flexibility. Another outcome of the discussion was an agreement that NASA should have an orbital rendezvous program which could stand alone as well as being a part of the manned lunar program. A task group was named to define the elements of the program insofar as possible. Members of the group were George M. Low, Chairman, Eldon W. Hall, A. M. Mayo, Ernest O. Pearson, Jr., and Oran W. Nicks, all of NASA Headquarters; Maxime A. Faget of STG; and H. H. Koelle of Marshall Space Flight Center. This group became known as the Low Committee.

• 1961 January 10 - Conference on lunar orbit rendezvous for the Apollo program - Program: Apollo.
  A conference was held at the Langley Research Center between representatives of STG and Langley to discuss the feasibility of incorporating a lunar orbit rendezvous phase into the Apollo program. Attending the meeting for STG were Robert L. O'Neal, Owen E. Maynard, and H. Kurt Strass, and for the Langley Research Center, John C. Houbolt, Clinton E. Brown, Manuel J. Queijo, and Ralph W. Stone, Jr. The presentation by Houbolt centered on a performance analysis which showed the weight saving to be gained by the lunar rendezvous technique as opposed to the direct ascent mode. According to the analysis, a saving in weight of from 20 to 40 percent could be realized with the lunar orbit rendezvous technique.

• 1961 January 16 - Second meeting of the Low Committee - Program: Apollo.
  At the second meeting of the Manned Lunar Landing Task Group (Low Committee), a draft position paper was presented by George M. Low, Chairman. A series of reports on launch vehicle capabilities, spacecraft, and lunar program support were presented and considered for possible inclusion in the position paper.

• 1961 January 24 - Low Committee first draft report - Program: Apollo.
  The Manned Lunar Landing Task Group (Low Committee) submitted its first draft report to NASA Associate Administrator Robert C. Seamans, Jr. A section on detailed costs and schedules still was in preparation and a detailed itemized backup report was expected to be available in mid- February.

• 1961 February 27 - NASA Inter-Center meeting on space rendezvous - Program: Apollo.
  A NASA inter-Center meeting on space rendezvous was held in Washington, D.C. Air Force and NASA programs were discussed and the status of current studies was presented by NASA Centers. Members of the Langley Research Center outlined the basic concepts of the lunar orbit rendezvous method of accomplishing the lunar landing mission.

• 1961 March 1 - The midterm review of the Apollo feasibility studies was held at STG - Program: Apollo.
  The midterm review of the Apollo feasibility studies was held at STG. Oral status reports were made by officials of Convair Astronautics Division of the General Dynamics Corporation on March 1, The Martin Company on March 2, and the General Electric Company on March 3. The reports described the work accomplished, problems unsolved, and future plans. Representatives of all NASA Centers attended the meetings, including a majority of the members of the Apollo Technical Liaison Groups. Members of these Groups formed the nucleus of the mid-term review groups which met during the three-day period and compiled lists of comments on the presentations for later discussions with the contractors.

• 1961 April 19 - Manned Lunar Landing via Rendezvous report - Program: Apollo.
  A circular, "Manned Lunar Landing via Rendezvous," was prepared by John C. Houbolt from material supplied by himself, John D. Bird, Max C. Kurbjun, and Arthur W. Vogeley, who were members of the Langley Research Center space station subcommittee on rendezvous. Other members of the subcommittee at various times included W. Hewitt Phillips, John M. Eggleston, John A. Dodgen, and William D. Mace.

• 1961 April 19 - Apollo MORAD, ARP, and MALLIR recommendations - Program: Apollo.
  Recommendations on immediate steps to be taken so that the three key projects - MORAD (Manned Orbital Rendezvous and Docking), ARP (Apollo Rendezvous Phases), and MALLIR (Manned Lunar Landing Involving Rendezvous) - could get under way were:
  • Approve the MORAD project and let a study contract to consider general aspects of the Scout rendezvous vehicle design, definite planning and schedules, and tie down cost estimates more exactly.
  • Delegate responsibility to STG to give accelerated consideration to rendezvous aspects of Apollo, tailoring developments to fit directly into the MALLIR project.
  • Let a study contract to establish preliminary design, scheduling, and cost figures for the three projects.

• 1961 May 25 - Lundin Committee to assess Lunar landing mission - Program: Apollo.
  Robert C. Seamans, Jr., NASA's Associate Administrator, requested the Directors of the Office of Launch Vehicle Programs and the Office of Advanced Research Programs to bring together members of their staffs with other persons from NASA Headquarters to assess a wide variety of possible ways of accomplishing the lunar landing mission. This study was to supplement the one being done by the Ad Hoc Task Group for Manned Lunar Landing Study (Fleming Committee) but was to be separate from it. Additional Details: Lundin Committee to assess Lunar landing mission.

• 1961 May 31 - Lunar orbit rendezvous plan - Program: Apollo.
  Basic concepts of the lunar orbit rendezvous plan were presented to the Lundin Committee by John C. Houbolt of Langley Research Center.

• 1961 June 26 - Langley Research Center lunar landing paper - Program: Apollo.
  Maxime A. Faget, Paul E. Purser, and Charles J. Donlan of STG met with Arthur W. Vogeley, Clinton E. Brown, and Laurence K. Loftin, Jr., of Langley Research Center on a "lunar landing" paper. Faget's outline was to be used, with part of the information to be worked up by Vogeley.

• 1961 June 30 - Lunar orbit rendezvous briefing - Program: Apollo.
  Members of Langley Research Center briefed the Heaton Committee on the lunar orbit rendezvous method of accomplishing the manned lunar landing mission.

• 1961 July 31 - Langley simulated spacecraft flights in approaching the moon's surface - Program: Apollo.
  Langley Research Center simulated spacecraft flights at speeds of 8,200 to 8,700 feet per second in approaching the moon's surface. With instruments preset to miss the moon's surface by 40 to 80 miles, pilots with control of thrust and torques about all three axes of the craft learned to establish orbits 10 to 90 miles above the surface, using a graph of vehicle rate of descent and circumferential velocity, an altimeter, and vehicle attitude and rate meters, as reported by Manuel J. Queijo and Donald R. Riley of Langley.

• 1961 August 23 - Golovin Committee evaluates three rendezvous methods for manned lunar landing - Program: Apollo. Launch Vehicle: Saturn V.
  The Large Launch Vehicle Planning Group (Golovin Committee) notified the Marshal! Space Flight Center (MSFC), Langley Research Center, and the Jet Propulsion Laboratory (JPL) that the Group was planning to undertake a comparative evaluation of three types of rendezvous operations and direct flight for manned lunar landing. Rendezvous methods were earth orbit, lunar orbit, and lunar surface. MSFC was requested to study earth orbit rendezvous, Langley to study lunar orbit rendezvous, and JPL to study lunar surface rendezvous. The NASA Office of Launch Vehicle Programs would provide similar information on direct ascent. Additional Details: Golovin Committee evaluates three rendezvous methods for manned lunar landing.

• 1961 September 14 - Studies being done on rendezvous modes for accomplishing a manned lunar landing - Program: Apollo.
  In a memorandum to the Large Launch Vehicle Planning Group (LLVPG) staff, Harvey Hall of NASA described the studies being done by the Centers on rendezvous modes for accomplishing a manned lunar landing. These studies had been requested from Langley Research Center, Marshall Space Flight Center, and the Jet Propulsion Laboratory on August 23. STG was preparing separate documentation on the lunar orbit rendezvous mode. An LLVPG team to undertake a comparative evaluation of rendezvous and direct ascent techniques had been set up. Members of the team included Hall and Norman Rafel of NASA and H. Braham and L. M. Weeks of Aerospace Corporation.

  The evaluation would consider:

  • Effect of total flight time on specifications and reliability of equipment and on personnel.
  • Effect of vehicle system reliability in each case, including the number of engine starts and restarts.
  • Dependence on data, data-rate, and distance from ground station for control of assembly and refueling operations
  • Launch and injection windows
  • Effect of differences in the total weight propelled to earth escape velocity
  • Relative merits of lunar gravity and of a lunar base in general versus an orbital station for rendezvous and assembly purposes.
  Reliability estimates on vehicles would be based on LLVPG data; estimates on equipment would rely on experience with similar types in known applications.

• 1961 October 31 - Manned Lunar-Landing through use of Lunar-Orbit Rendezvous - Program: Apollo.
  Under the direction of John C. Houbolt of Langley Research Center, a two-volume work entitled "Manned Lunar-Landing through use of Lunar-Orbit Rendezvous" was presented to the Golovin Committee (organized on July 20). The study had been prepared by Houbolt, John D. Bird, Arthur W. Vogeley, Ralph W. Stone, Jr., Manuel J. Queijo, William H. Michael, Jr., Max C. Kurbjun, Roy F. Brissenden, John A. Dodgen, William D. Mace, and others of Langley. The Golovin Committee had requested a mission plan using the lunar orbit rendezvous concept. Bird, Michael, and Robert H. Tolson appeared before the Committee in Washington to explain certain matters of trajectory and lunar stay time not covered in the document.

• 1961 November 15 - Houbolt letter on lunar orbit rendezvous (LOR) plan - Program: Apollo.
  In a letter to NASA Associate Administrator Robert C. Seamans, Jr., John C. Houbolt of Langley Research Center presented the lunar orbit rendezvous (LOR) plan and outlined certain deficiencies in the national booster and manned rendezvous programs. This letter protested exclusion of the LOR plan from serious consideration by committees responsible for the definition of the national program for lunar exploration.

• 1962 January 1 - Grumman study on lunar orbit rendezvous - Program: Apollo.
  The Grumman Aircraft Engineering Corporation developed a detailed, company-funded study on the lunar orbit rendezvous technique: characteristics of the system (relative cost of direct ascent, earth orbit rendezvous, and lunar orbit rendezvous); developmental problems (communications, propulsion); and elements of the system (tracking facilities, etc.). Joseph M. Gavin was appointed in the spring to head the effort, and Robert E. Mullaney was designated program manager.

• 1962 February 6 - Langley presentation of lunar orbit rendezvous - Program: Apollo.
  John C. Houbolt of Langley Research Center and Charles W. Mathews of MSC made a presentation of lunar orbit rendezvous versus earth orbit rendezvous to the Manned Space Flight Management Council.

• 1962 February 9 - Ad Hoc Lunar Landing Module Working Group - Program: Apollo.
  Robert R. Gilruth, MSC Director, in a letter to NASA Headquarters, described the Ad Hoc Lunar Landing Module Working Group which was to be under the direction of the Apollo Spacecraft Project Office. The Group would determine what constraints on the design of the lunar landing module were applicable to the effort of the Lewis Research Center. Gilruth asked that Eldon W. Hall represent NASA Headquarters in this Working Group. (At this time, the lunar landing module was conceived as being that part of the spacecraft which would actually land on the moon and which would contain the propulsion system necessary for launch from the lunar surface and injection into transearth trajectory. Pending a decision on the lunar mission mode, the actual configuration of the module was not yet clearly defined.)

• 1962 March 1 - Chance Vought to study spacecraft rendezvous - Program: Apollo.
  NASA Headquarters selected the Chance Vought Corporation of Ling-Temco-Vought, Inc., as a contractor to study spacecraft rendezvous. A primary part of the contract would be a flight simulation study exploring the capability of an astronaut to control an Apollo-type spacecraft.

• 1962 March 29 - Chance Vought briefed on lunar orbit rendezvous - Program: Apollo.
  Members of Langley Research Center briefed representatives of the Chance Vought Corporation of Ling- Temco-Vought, Inc., on the lunar orbit rendezvous method of accomplishing the lunar landing mission. The briefing was made in connection with the study contract on spacecraft rendezvous awarded by NASA Headquarters to Chance Vought on March 1.

• 1962 March 30 - Preliminary Apollo program schedules - Program: Apollo. Launch Vehicle: Saturn I, Saturn V.
  A small group within the MSC Apollo Spacecraft Project Office developed a preliminary program schedule for three approaches to the lunar landing mission: earth orbit rendezvous, direct ascent, and lunar orbit rendezvous. The exercise established a number of ground rules :
  • Establish realistic schedules that would "second guess" failures but provide for exploitation of early success.
  • Schedule circumlunar, lunar orbit, and lunar landing missions at the earliest realistic dates.
  • Complete the flight development of spacecraft modules and operational techniques, using the Saturn C-1 and C-1B launch vehicles, prior to the time at which a "man-rated" C-5 launch vehicle would become available.
  • Develop the spacecraft operational techniques in "buildup" missions that would progress generally from the simple to the complex.
  • Use the spacecraft crew at the earliest time and to the maximum extent, commensurate with safety considerations, in the development of the spacecraft and its subsystems.
  The exercise also provided a basis for proceeding with the development of definitive schedules and a program plan.

• 1962 April 16 - Lunar orbit rendezvous technique - Program: Apollo.
  Representatives of MSC made a formal presentation at Marshall Space Flight Center on the lunar orbit rendezvous technique for accomplishing the lunar mission.

• 1962 April 24 - Rosen recommends Saturn C-5 design and lunar orbit rendezvous - Program: Apollo. Launch Vehicle: Saturn V.
  Milton W. Rosen, NASA Office of Manned Space Flight Director of Launch Vehicles and Propulsion, recommended that the S-IVB stage be designed specifically as the third stage of the Saturn C-5 and that the C-5 be designed specifically for the manned lunar landing using the lunar orbit rendezvous technique. The S-IVB stage would inject the spacecraft into a parking orbit and would be restarted in space to place the lunar mission payload into a translunar trajectory. Rosen also recommended that the S- IVB stage be used as a flight test vehicle to exercise the command module (CM), service module (SM), and lunar excursion module (LEM) (previously referred to as the lunar excursion vehicle (LEV)) in earth orbit missions. The Saturn C-1 vehicle, in combination with the CM, SM, LEM, and S-IVB stage, would be used on the most realistic mission simulation possible. This combination would also permit the most nearly complete operational mating of the CM, SM, LEM, and S-IVB prior to actual mission flight.

• 1962 April 24 - Indecision on the lunar mission mode causing delays in Apollo program - Program: Apollo.
  MSC Associate Director Walter C. William reported to the Manned Space Flight Management Council that the lack of a decision on the lunar mission mode was causing delays in various areas of the Apollo spacecraft program, especially the requirements for the portions of the spacecraft being furnished by NAA.

• 1962 April 30 - Advantages of lunar orbit rendezvous - Program: Apollo.
  John C. Houbolt of Langley Research Center, writing in the April issue of Astronautics, outlined the advantages of lunar orbit rendezvous for a manned lunar landing as opposed to direct flight from earth or earth orbit rendezvous. Under this concept, an Apollo-type spacecraft would fly directly to the moon, go into lunar orbit, detach a small landing craft which would land on the moon and then return to the mother craft, which would then return to earth. The advantages would be the much smaller craft performing the difficult lunar landing and takeoff, the possibility of optimizing the smaller craft for this one function, the safe return of the mother craft in event of a landing accident, and even the possibility of using two of the small craft to provide a rescue capability.

• 1962 May 3 - Presentation on the lunar orbit rendezvous technique - Program: Apollo.
  A presentation on the lunar orbit rendezvous technique was made to D. Brainerd Holmes, Director, NASA Office of Manned Space Flight, by representatives of the Apollo Spacecraft Project Office. A similar presentation to NASA Associate Administrator Robert C. Seamans, Jr., followed on May 31.

• 1962 May 6 - Preliminary Statement of Work for Apollo lunar excursion module - Program: Apollo.
  A preliminary Statement of Work for a proposed lunar excursion module was completed, although the mission mode had not yet been selected.

• 1962 May 29 - Schedule for contract for development of Apollo lunar excursion module - Program: Apollo.
  A schedule for the letting of a contract for the development of a lunar excursion module was presented to the Manned Space Flight Management Council by MSC Director Robert R. Gilruth in anticipation of a possible decision to employ the lunar rendezvous technique in the lunar landing mission.

• 1962 July 1 - Delta V requirements for the Apollo lunar landing mission were established - Program: Apollo.
  The delta V (rate of incremental change in velocity) requirements for the lunar landing mission were established and coordinated with NAA by the Apollo Spacecraft Project Office.

• 1962 July 10 - Report on a simulated lunar landing trainer - Program: Apollo.
  Charles W. Frick, MSC Apollo Project Office Manager, assigned MIT Instrumentation Laboratory to report on a simulated lunar landing trainer using guidance and navigation equipment and other displays as necessary or proposed.

• 1962 July 25 - Invitation to bid for the Apollo lunar excursion module - Program: Apollo.
  MSC invited 11 firms to submit research and development proposals for the lunar excursion module (LEM) for the manned lunar landing mission. The firms were Lockheed Aircraft Corporation, The Boeing Airplane Company, Northrop Corporation, Ling-Temco-Vought, Inc., Grumman Aircraft Engineering Corporation, Douglas Aircraft Company, General Dynamics Corporation, Republic Aviation Corporation, Martin- Marietta Company, North American Aviation, Inc., and McDonnell Aircraft Corporation. Additional Details: Invitation to bid for the Apollo lunar excursion module.

• 1962 July 30 - Conclusions on the selection of a lunar mission mode based on studies conducted in 1961 and 1962 - Program: Apollo. Launch Vehicle: Nova, Saturn V.
  The Office of Systems under NASA's Office of Manned Space Flight summarized its conclusions on the selection of a lunar mission mode based on NASA and industry studies conducted in 1961 and 1962:
  • There were no significant technical problems which would preclude the acceptance of any of the modes, if sufficient time and money were available. (The modes considered were the C-5 direct ascent, C-5 earth orbit rendezvous (EOR), C-5 lunar orbit rendezvous (LOR), Nova direct ascent, and solid-fuel Nova direct ascent.)
  • The C-5 direct ascent technique was characterized by high development risk and the least flexibility for further development.
  • The C-5 EOR mode had the lowest probability of mission success and the greatest development complexity.
  • The Nova direct ascent method would require the development of larger launch vehicles than the C-5. However, it would be the least complex from an operational and subsystem standpoint and had greater crew safety and initial mission capabilities than did LOR.
  • The solid-fuel Nova direct flight mode would necessitate a launch vehicle development parallel to the C-5. Such a development could not be financed under current budget allotments.
  • Only the LOR and EOR modes would make full use of the development of the C-5 launch vehicle and the command and service modules. Based on technical considerations, the LOR mode was distinctly preferable.
  • The Directors of MSC and Marshall Space Flight Center had both expressed strong preference for the LOR mode.
  On the basis of these conclusions, the LOR mode was recommended as most suitable for the manned lunar landing mission. (The studies summarized in this document were used by the Manned Space Flight Management Council in their mission mode decision on June 22.)

• 1962 July 31 - Preliminary design of the Apollo lunar landing radar - Program: Apollo.
  NAA selected the lunar landing radar and completed the block diagram for the spacecraft rendezvous radar. Preliminary design was in progress on both types of radar.

• 1962 August 11 - Eight companies to bid on Apollo lunar excursion module - Program: Apollo.
  Of the 11 companies invited to bid on the lunar excursion module on July 25, eight planned to respond. NAA had notified MSC that it would not bid on the contract. No information had been received from the McDonnell Aircraft Corporation and it was questionable whether the Northrop Corporation would respond.

• 1962 August 14 - LEM added to Apollo CSM Statement of Work - Program: Apollo.
  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: LEM added to Apollo CSM Statement of Work.

• 1962 September 4 - Nine industry proposals for the Apollo lunar excursion module received - Program: Apollo.
  Nine industry proposals for the lunar excursion module were received from The Boeing Company, Douglas Aircraft Company, General Dynamics Corporation, Grumman Aircraft Engineering Corporation, Ling-Temco-Vought, Inc., Lockheed Aircraft Corporation, Martin-Marietta Corporation, Northrop Corporation, and Republic Aviation Corporation. NASA evaluation began the next day. Additional Details: Nine industry proposals for the Apollo lunar excursion module received.

• 1962 September 5 - Study of Apollo docking and crew transfer - Program: Apollo.
  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 September 21 - Contract with Armour Research Foundation for investigation of conditions on the lunar surface - Program: Apollo.
  NASA contracted with the Armour Research Foundation for an investigation of conditions likely to be found on the lunar surface. Research would concentrate first on evaluating the effects of landing velocity, size of the landing area, and shape of the landing object with regard to properties of the lunar soils. Earlier studies by Armour had indicated that the lunar surface might be composed of very strong material. Amour reported its findings during the first week of November.

• 1962 September 30 - Apollo lunar excursion module systems - Program: Apollo.
  The lunar excursion module was defined as consisting of 12 principal systems: guidance and navigation, stabilization and control, propulsion, reaction control, lunar touchdown, structure including landing and docking systems, crew, environmental control, electrical power, communications, instrumentation, and experimental instrumentation. A consideration of prime importance to practically all systems was the possibility of using components from Project Mercury or those under development for Project Gemini.

• 1962 October 24 - Final manned lunar landing mode report - Program: Apollo.
  Faced by opposition of mode selection by Jerome Wiesner, Kennedy's science adviser, NASA let contracts to McDonnell and STL for direct two-man flight modes. Both concluded that it was feasible but would require LH2/LOX stages for descent and ascent from lunar surface, which NASA/STG adamantly opposed. This was also the last stab - for the time being - at 'lunar Gemini'.

  The Office of Systems under NASA's Office of Manned Space Flight completed a manned lunar landing mode comparison embodying the most recent studies by contractors and NASA Centers. The report was the outgrowth of the decision announced by NASA on July 11 to continue studies on lunar landing modes while basing planning and procurement primarily on the lunar orbit rendezvous (LOR) technique. Additional Details: Final manned lunar landing mode report.

• 1962 November 2 - Lunar surface might not be covered with dust layers - Program: Apollo.
  The Amour Research Foundation reported to NASA that the surface of the moon might not be covered with layers of dust. The first Armour studies showed that dust particles become harder and denser in a higher vacuum environment such as that of the moon, but the studies had not proved that particles eventually become bonded together in a rocket substance as the vacuum increases.

• 1962 November 7 - Selection of Grumman to build the Apollo lunar excursion module - Program: Apollo.
  NASA announced that the Grumman Aircraft Engineering Corporation had been selected to build the lunar excursion module of the three-man Apollo spacecraft under the direction of MSC. The contract, still to be negotiated, was expected to be worth about $350 million, with estimates as high as $1 billion by the time the project would be completed. Additional Details: Selection of Grumman to build the Apollo lunar excursion module.

• 1962 November 19 - Negotiations on the lunar excursion module (Apollo LEM) contract begin - Program: Apollo.
  About 100 Grumman Aircraft Engineering Corporation and MSC representatives began seven weeks of negotiations on the lunar excursion module (LEM) contract. After agreeing on the scope of work and on operating and coordination procedures, the two sides reached fiscal accord. Negotiations were completed on January 3, 1963. Eleven days later, NASA authorized Grumman to proceed with LEM development.

• 1962 November 26 - Inflight practice at orbital maneuvering said to be essential for lunar missions - Program: Apollo.
  At a news conference in Cleveland, Ohio, during the 10-day Space Science Fair there, NASA Deputy Administrator Hugh L. Dryden stated that inflight practice at orbital maneuvering was essential for lunar missions. He believed that landings would follow reconnaissance of the moon by circumlunar and near- lunar-surface flights.

• 1962 November 30 - Study of Apollo CSM-LEM transposition and docking - Program: Apollo.
  North American completed a study of CSM-LEM transposition and docking. During a lunar mission, after the spacecraft was fired into a trajectory toward the moon, the CSM would separate from the adapter section containing the LEM. It would then turn around, dock with the LEM, and pull the second vehicle free from the adapter. The contractor studied three methods of completing this maneuver: free fly-around, tethered fly- around, and mechanical repositioning. Of the three, the company recommended the free fly-around, based on NASA's criteria of minimum weight, simplicity of design, maximum docking reliability, minimum time of operation, and maximum visibility.

  Also investigated was crew transfer from the CM to the LEM, to determine the requirements for crew performance and, from this, to define human engineering needs. North American concluded that a separate LEM airlock was not needed but that the CSM oxygen supply system's capacity should be increased to effect LEM pressurization.

  On November 29, North American presented the results of docking simulations, which showed that the free flight docking mode was feasible and that the 45-kilogram (100-pound) service module (SM) reaction control system engines were adequate for the terminal phase of docking. The simulations also showed that overall performance of the maneuver was improved by providing the astronaut with an attitude display and some form of alignment aid, such as probe.

• 1962 December 10 - Selection of lunar orbit rendezvous for Apollo explained to Kennedy - Program: Apollo.
  NASA Administrator James E. Webb, in a letter to the President, explained the rationale behind the Agency's selection of lunar orbit rendezvous (rather than either direct ascent or earth orbit rendezvous) as the mode for landing Apollo astronauts on the moon. Arguments for and against any of the three modes could have been interminable: "We are dealing with a matter that cannot be conclusively proved before the fact," Webb said. "The decision on the mode . . . had to be made at this time in order to maintain our schedules, which aim at a landing attempt in late 1967."

• 1962 December 11 - Apollo LEM docking study authorized - Program: Apollo.
  NASA authorized North American's Columbus, Ohio, Division to proceed with a LEM docking study.

• 1962 December 20 - Apollo LEM's descent engine might create a dust storm on the lunar surface - Program: Apollo.
  MSC prognosticated that, during landing, exhaust from the LEM's descent engine would kick up dust on the moon's surface, creating a dust storm. Landings should be made where surface dust would be thinnest.

• 1962 December 31 - Project Apollo lunar landing mission design - Program: Apollo.
  MSC prepared the Project Apollo lunar landing mission design. This plan outlined ground rules, trajectory analyses, sequences of events, crew activities, and contingency operations. It also predicted possible planning changes in later Apollo flights.

• 1962 December 31 - Grumman agreed to use existing Apollo components and subsystems in the LEM - Program: Apollo.
  Grumman agreed to use existing Apollo components and subsystems, where practicable, in the LEM This promised to simplify checkout and maintenance of spacecraft systems.

• 1963 January 16 - Three Apollo operational procedures for the first phase of descent from lunar orbit analyzed - Program: Apollo.
  The MSC Flight Operations Division's Mission Analysis Branch analyzed three operational procedures for the first phase of descent from lunar orbit:
  1. The first was a LEM-only maneuver. The LEM would transfer to an orbit different from that of the CSM but with the same period and having a pericynthion of 15,240 meters (50,000 feet). After one orbit and reconnaissance of the landing site, the LEM would begin descent maneuvers.
  2. The second method required the entire spacecraft (CSM/LEM) to transfer from the initial circular orbit to an elliptical orbit with a pericynthion of 15,240 meters (50,000 feet).
  3. The third technique involved the LEM's changing from the original 147-kilometer (80-nautical-mile) circular orbit to an elliptic orbit having a pericynthion of 15,240 meters (50,000 feet). The CSM, in turn, would transfer to an elliptic orbit with a pericynthion of 65 kilometers (30 nautical miles). This would enable the CSM to keep the LEM under observation until the LEM began its descent to the lunar surface.
  Comparisons of velocity changes and fuel requirements for the three methods showed that the second technique would use much more fuel than the others and, therefore, was not recommended for further consideration.

  (Apocynthion and pericynthion are the high and low points, respectively, of an object in orbit around the moon (as, for example, a spacecraft sent from earth). Apolune and perilune also refer to these orbital parameters, but these latter two words apply specifically to an object launched from the moon itself.)

• 1963 January 28 - Conference on the Apollo LEM electrical power system (EPS) - Program: Apollo.
  Following a technical conference on the LEM electrical power system (EPS), Grumman began a study to define the EPS configuration. Included was an analysis of EPS requirements and of weight and reliability for fuel cells and batteries. Total energy required for the LEM mission, including the translunar phase, was estimated at 61.3 kilowatt-hours. Upon completion of this and a similar study by MSC, Grumman decided upon a three-cell arrangement with an auxiliary battery. Capacity would be determined when the EPS load analysis was completed.

• 1963 January 30 - Selection of four companies as major Apollo LEM subcontractors - Program: Apollo.
  Grumman and NASA announced the selection of four companies as major LEM subcontractors:
  1. Rocketdyne for the descent engine
  2. Bell Aerosystems Company for the ascent engine
  3. The Marquardt Corporation for the reaction control system
  4. Hamilton Standard for the environmental control system

• 1963 January 31 - Contract to Chance Vought for study of guidance of the Apollo LEM in a lunar landing abort - Program: Apollo.
  MSC awarded a contract to Chance Vought Corporation for a study of guidance system techniques for the LEM in an abort during lunar landing.

• 1963 February 13 - Discussions with Rocketdyne on a throttleable Apollo LEM descent engine - Program: Apollo.
  Grumman began discussions with Rocketdyne on the development of a throttleable LEM descent engine. Engine specifications (helium injected, 10:1 thrust variation) had been laid down by MSC.

• 1963 February 13 - Reorganization of Apollo SPO - Program: Apollo.
  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 25 - Talks with Bell on development of the Apollo LEM ascent engine - Program: Apollo.
  Grumman began initial talks with the Bell Aerosystems Company on development of the LEM ascent engine. Complete specifications were expected by March 2.

• 1963 February 26 - Orbital constraints on Apollo CSM - Program: Apollo.
  Two aerospace technologists at MSC, James A. Ferrando and Edgar C. Lineberry, Jr., analyzed orbital constraints on the CSM imposed by the abort capability of the LEM during the descent and hover phases of a lunar mission. Their study concerned the feasibility of rendezvous should an emergency demand an immediate return to the CSM.

  Ferrando and Lineberry found that, once abort factors are considered, there exist "very few" orbits that are acceptable from which to begin the descent. They reported that the most advantageous orbit for the CSM would be a 147-kilometer (80-nautical-mile) circular one.

• 1963 February 27 - Alternate Apollo LEM descent propulsion system - Program: Apollo.
  Aviation Daily reported an announcement by Frank Canning, Assistant LEM Project Manager at Grumman, that a Request for Proposals would be issued in about two weeks for the development of an alternate descent propulsion system. Because the descent stage presented what he called the LEM's "biggest development problem," Canning said that the parallel program was essential.

• 1963 February 27 - Apollo Mission Planning Panel - Program: Apollo.
  The Apollo Mission Planning Panel held its organizational meeting at MSC. The panel's function was to develop the lunar landing mission design, coordinate trajectory analyses for all Saturn missions, and develop contingency plans for all manned Apollo missions.

  Membership on the panel included representatives from MSC, MSFC, NASA Headquarters, North American, Grumman, and MIT, with other NASA Centers being called on when necessary. By outlining the most accurate mission plan possible, the panel would ensure that the spacecraft could satisfy Apollo's anticipated mission objectives. Most of the panel's influence on spacecraft design would relate to the LEM, which was at an earlier stage of development than the CSM. The panel was not given responsibility for preparing operational plans to be used on actual Apollo missions, however.

• 1963 February 28 - One-tenth scale model of the Apollo LEM for stage separation tests - Program: Apollo.
  Grumman began fabrication of a one-tenth scale model of the LEM for stage separation tests. In launching from the lunar surface, the LEM's ascent engine fires just after pyrotechnic severance of all connections between the two stages, a maneuver aptly called "fire in the hole."

  Also, Grumman advised that, from the standpoint of landing stability, a five-legged LEM was unsatisfactory. Under investigation were a number of landing gear configurations, including retractable legs.

• 1963 March 4 - Discussions with Hamilton Standard on Apollo LEM environmental control system - Program: Apollo.
  Grumman began initial discussions with Hamilton Standard on the development of the LEM environmental control system.

• 1963 March 7 - Report on power sources for the Apollo LEM - Program: Apollo.
  Grumman representatives presented their technical study report on power sources for the LEM. They recommended three fuel cells in the descent stage (one cell to meet emergency requirements), two sets of fluid tanks, and two batteries for peak power loads. For industrial competition to develop the power sources, Grumman suggested Pratt and Whitney Aircraft and GE for the fuel cells, and Eagle-Picher, Electrical Storage Battery, Yardney, Gulton, and Delco-Remy for the batteries.

• 1963 March 10 - Grumman presented its first monthly progress report on the Apollo LEM - Program: Apollo.
  Grumman presented its first monthly progress report on the LEM. In accordance with NASA's list of high-priority items, principal engineering work was concentrated on spacecraft and subsystem configuration studies, mission plans and test program investigations, common usage equipment surveys, and preparation for implementing subcontractor efforts.

• 1963 March 11 - Contract talks with Marquardt for Apollo LEM reaction control system - Program: Apollo.
  Grumman began early contract talks with the Marquardt Corporation for development of the LEM reaction control system.

• 1963 March 11 - First Apollo LM fire-in-the-hole model test - Program: Apollo.
  Grumman completed its first "fire-in-the-hole" model test. Even though preliminary data agreed with predicted values, they nonetheless planned to have a support contractor, the Martin Company, verify the findings.

• 1963 March 11 - Definitive contract formalized for the Apollo Lunar Excursion Module - Program: Apollo.
  NASA announced signing of the contract with Grumman for development of the LEM. Company officials had signed the document on January 21 and, following legal reviews, NASA Headquarters had formally approved the agreement on March 7. Under the fixed-fee contract (NAS 9-1100) ($362.5 million for costs and $25.4 million in fees) Grumman was authorized to design, fabricate, and deliver nine ground test and 11 flight vehicles. The contractor would also provide mission support for Apollo flights. MSC outlined a developmental approach, incorporated into the contract as "Exhibit B, Technical Approach," that became the "framework within which the initial design and operational modes" of the LEM were developed.

• 1963 March 14 - Bidders' conference for Apollo LEM mechanically throttled descent engine - Program: Apollo.
  A bidders' conference was held at Grumman for a LEM mechanically throttled descent engine to be developed concurrently with Rocketdyne's helium injection descent engine. Corporations represented were Space Technology Laboratories; United Technology Center, a division of United Aircraft Corporation; Reaction Motors Division, Thiokol Chemical Corporation; and Aerojet-General Corporation. Technical and cost proposals were due at Grumman on April 8.

• 1963 March 27 - Firm requirements for the lunar landing mission - Program: Apollo.
  The Apollo Mission Planning Panel set forth two firm requirements for the lunar landing mission. First, both LEM crewmen must be able to function on the lunar surface simultaneously. MSC contractors were directed to embody this requirement in the design and development of the Apollo spacecraft systems. Second, the panel established duration limits for lunar operations. These limits, based upon the 48-hour LEM operation requirement, were 24 hours on the lunar surface and 24 hours in flight on one extreme, and 45 surface hours and 3 flight hours on the other. Grumman was directed to design the LEM to perform throughout this range of mission profiles.

• 1963 March 31 - Study on ablative versus regenerative cooling for the Apollo LEM ascent engine - Program: Apollo.
  RCA completed a study on ablative versus regenerative cooling for the thrust chamber of the LEM ascent engine. Because of low cooling margins available with regenerative cooling, Grumman selected the ablative method, which permitted the use of either ablation or radiation cooling for the nozzle extension.

• 1963 March 31 - Preliminary design specifications for the Apollo LEM communications system - Program: Apollo.
  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 March 31 - MSC sent MIT and Grumman radar configuration requirements for the Apollo LEM - Program: Apollo.
  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 March 31 - Stowage of crew equipment in both the Apollo CM and LEM worked out - Program: Apollo.
  MSC reported that stowage of crew equipment, some of which would be used in both the CM and the LEM, had been worked out. Two portable life support systems and three pressure suits and thermal garments were to be stowed in the CM. Smaller equipment and consumables would be distributed between modules according to mission phase requirements.

• 1963 April 1 - Grumman began Lunar Hover and Landing Simulation IIIA tests - Program: Apollo.
  Grumman began "Lunar Hover and Landing Simulation IIIA," a series of tests simulating a LEM landing. Crew station configuration and instrument panel layout were representative of the actual vehicle.

  Through this simulation, Grumman sought primarily to evaluate the astronauts' ability to perform the landing maneuver manually, using semiautomatic as well as degraded attitude control modes. Other items evaluated included the flight control system parameters, the attitude and thrust controller configurations, the pressure suit's constraint during landing maneuvers, the handling qualities and operation of LEM test article 9 as a freeflight vehicle, and manual abort initiation during the terminal landing maneuver.

• 1963 April 17 - Preliminary configuration freeze for the Apollo LEM - Program: Apollo.
  At a mechanical systems meeting at MSC, customer and contractor achieved a preliminary configuration freeze for the LEM. Several features of the design of the two stages were agreed upon:

  Descent

  four cylindrical propellant tanks (two oxidizer and two fuel); four- legged deployable landing gear

  Ascent

  a cylindrical crew cabin (about 234 centimeters (92 inches) in diameter) and a cylindrical tunnel (pressurized) for equipment stowage; an external equipment bay.

  Additional Details: Preliminary configuration freeze for the Apollo LEM.

• 1963 April 30 - Apollo LEM reaction control system (RCS) to be equipped with dual interconnected tanks - Program: Apollo.
  Grumman recommended that the LEM reaction control system (RCS) be equipped with dual interconnected tanks, separately pressurized and employing positive expulsion bladders. The design would provide for an emergency supply of propellants from the main ascent propulsion tanks. The RCS oxidizer to fuel ratio would be changed from 2.0:1 to 1.6:1. MSC approved both of these changes.

• 1963 April 30 - Grumman studies on common usage of Apollo CSM/LM communications - Program: Apollo.
  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 1 - Rocketdyne gvien go ahead for Apollo LEM descent engine - Program: Apollo.
  Grumman reported that it had advised North American's Rocketdyne Division to go ahead with the lunar excursion module descent engine development program. Negotiations were complete and the contract was being prepared for MSC's review and approval. The go-ahead was formally issued on May 2.

• 1963 May 2 - CM television camera made compatible with that in the Apollo LEM - Program: Apollo.
  NASA, North American, Grumman, and RCA representatives determined the alterations needed to make the CM television camera compatible with that in the LEM: an additional oscillator to provide synchronization, conversion of operating voltage from 115 AC to 28 DC, and reduction of the lines per frame from 400 to 320.

• 1963 May 6 - Apollo LEM manual control simulated - Program: Apollo.
  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 7 - Reorganization of Apollo SPO - Program: Apollo.
  MSC announced a reorganization of ASPO:

  Acting Manager:

  Robert O. Piland

  Deputy Manager, Spacecraft:

  Robert O. Piland

  Assistant Deputy Manager for CSM:

  Caldwell C. Johnson

  Deputy Manager for System Integration:

  Alfred D. Mardel

  Deputy Manager LEM:

  James L. Decker

  Manager, Spacecraft Systems Office:

  David W. Gilbert

  Manager, Project Integration Office:

  J. Thomas Markley

• 1963 May 10 - The first meeting of the Apollo LEM Flight Technology Systems Panel was held at MSC - Program: Apollo.
  The first meeting of the LEM Flight Technology Systems Panel was held at MSC. The panel was formed to coordinate discussions on all problems involving weight control, engineering simulation, and environment. The meeting was devoted to a review of the status of LEM engineering programs.

• 1963 May 11 - STL to build the mechanically throttled descent engine for the Apollo LEM - Program: Apollo.
  Grumman selected Space Technology Laboratories (STL) to develop and fabricate a mechanically throttled descent engine for the LEM, paralleling Rocketdyne's effort. Following NASA and MSC concurrence, Grumman began negotiations with STL on June 1.

• 1963 May 14 - Quality Control Program Plan for the Apollo LEM - Program: Apollo.
  Grumman submitted to NASA a Quality Control Program Plan for the LEM, detailing efforts in management, documentation, training, procurement, and fabrication.

• 1963 May 20 - Status report on the Apollo LEM landing gear design and Apollo LEM stowage height - Program: Apollo. Launch Vehicle: Saturn V.
  At a meeting on mechanical systems at MSC, Grumman presented a status report on the LEM landing gear design and LEM stowage height. On May 9, NASA had directed the contractor to consider a more favorable lunar surface than that described in the original Statement of Work. Accordingly, Grumman recommended an envelope of LEM S-IVB clearance of 152.4 centimeters (40 inches) for a landing gear radius of 457 centimeters (180 inches). Beyond this radius, a different gear scheme was considered more suitable but would require greater clearances. The landing gear envelope study was extended for one month to establish a stowed height of the LEM above the S-IVB for adapter design.

• 1963 May 22 - Grumman representatives met with the Apollo ASPO Electrical Systems Panel (ESP) - Program: Apollo.
  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-space suit interface problems - Program: Apollo.
  Meeting in Bethpage, N. Y., officials from MSC, Grumman, Hamilton Standard, International Latex, and North American examined LEM-space suit interface problems. This session resulted in several significant decisions:
  • Suit evaluation would include a vehicle mockup in an aircraft flying zero and one-sixth g trajectories.
  • The suit assembly emergency oxygen supply would serve also as the backup pressurization and oxygen supply during crew transfer from the CM to the LEM.
  • The four-hour operating requirement for the portable life support system (PLSS) should not be considered for normal operation.
  • Pending final design of a waste management system, Grumman would retain provisions for stowage of human wastes.
  • The thermal garment would not normally be worn inside the LEM.
  • The PLSS battery would be charged before earth launch.
  • Prototype Apollo space suits were to be delivered to Grumman as soon as possible for evaluation and vehicle design.

• 1963 May 23 - Apollo LEM and CSM to incorporate phase-coherent S-band transponders - Program: Apollo.
  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 May 23 - Major redesign of the Apollo guidance computer - Program: Apollo.
  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 May 29 - Grumman presented its Apollo LEM engineering and simulation plans - Program: Apollo.
  Grumman presented its LEM engineering and simulation plans to MSC, stating that their existing facilities and contracted facilities at North American in Columbus, Ohio, and at LTV would be used throughout 1963. Two part-task LEM simulators would be operational at Grumman early in 1964, with a complete mission simulator available in 1965. MSC had approved the contractor's procurement of two visual display systems for use in the simulators.

• 1963 May 30 - Apollo LEM descent engine development program - Program: Apollo.
  Rocketdyne reported to Grumman on the LEM descent stage engine development program. Revised measurements for the engine were: diameter, 137 centimeters (54 inches); length, 221 centimeters (87 inches) (30.5 centimeters (twelve inches) more than the original constraint that Grumman had imposed on Rocketdyne).

• 1963 May 31 - First estimates of reliability for the Apollo LEM - Program: Apollo.
  In its first estimates of reliability for the LEM, Grumman reported a 0.90 probability for mission success and 0.994 for crew safety. (The probabilities required by NASA were 0.984 and 0.9995, respectively.)

• 1963 May 31 - Titanium selected for the propellant tanks for the Apollo LEM descent stage - Program: Apollo.
  After a detailed comparison of titanium and aluminum propellant tanks for the LEM descent stage, Grumman selected the lighter titanium.

• 1963 May 31 - Grumman studied use of the PLSS lithium hydroxide cartridges in the Apollo LEM ECS - Program: Apollo.
  Grumman studied the possibility of using the portable life support system lithium hydroxide cartridges in the LEM environmental control system, and determined that such common usage was feasible. This analysis would be verified by tests at Hamilton Standard.

• 1963 May 31 - Grumman completed the Apollo LEM M-1 mockup - Program: Apollo.
  Grumman completed the LEM M-1 mockup and began installing equipment in the vehicle. Also, the contractor began revising cabin front design to permit comparisons of visibility.

• 1963 June 3 - Length of the spacecraft-Saturn V adapter had been increased from 8.077 meters to 8.89 meters - Program: Apollo. Launch Vehicle: Saturn V.
  MSC informed MSFC that the length of the spacecraft-Saturn V adapter had been increased from 807.7 centimeters to 889 centimeters (318 inches to 350 inches). The LEM would be supported in the adapter from a fixed structure on the landing gear.

• 1963 June 16 - MSC and Grumman assessed crew visibility requirements for the Apollo LEM - Program: Apollo.
  MSC and Grumman assessed crew visibility requirements for the LEM. The study included a series of helicopter flights in which simulated earthshine lighting conditions and LEM window configurations were combined with helicopter landings along representative LEM trajectories. These flights simulated the LEM's attitude, velocity, range, and dive angle in the final approach trajectory.

• 1963 June 16 - Apollo LEM crew to stand - Program: Apollo.
  MSC reported that crew systems engineers at the Center were assessing feasibility of having the LEM crew stand rather than sit. MSC requested Grumman also to look into having the crew fly the vehicle from a standing position. The concept was formally proposed at the August 27 crew systems meeting and was approved at the NASA-Grumman review of the LEM M-1 mockup on September 16-18.

• 1963 June 21 - Apollo LEM guidance and navigation system coordination meeting - Program: Apollo.
  MSC met with those contractors participating in the development of the LEM guidance and navigation system. Statements of Work for the LEM design concept were agreed upon. (Technical directives covering most of the work had been received earlier by the contractors.)

• 1963 June 25 - Apollo LEM landing gear design freeze - Program: Apollo. Launch Vehicle: Saturn V.
  MSC Director Robert R. Gilruth reported to the MSF Management Council that the LEM landing gear design freeze was now scheduled for August 31. Grumman had originally proposed a LEM configuration with five fixed legs, but LEM changes had made this concept impractical. The weight and overall height of the LEM had increased, the center of gravity had been moved upward, the LEM stability analysis had expanded to cover a wider range of landing conditions, the cruciform descent stage had been selected, and the interpretation of the lunar model had been revised. These changes necessitated a larger gear diameter than at first proposed. This, in turn, required deployable rather than fixed legs so the larger gear could be stored in the Saturn V adapter. MSC had therefore adopted a four-legged deployable gear, which was lighter and more reliable than the five-legged configuration.

• 1963 June 28 - RCA named as subcontractor for Apollo LEM electronics subsystems and for engineering support - Program: Apollo.
  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 June 30 - Apollo LTV abort simulation negotiations with Grumman completed - Program: Apollo.
  Planning and final details of LTV abort simulation negotiations with Grumman were completed. The abort experiments, to be conducted at LTV's aerospace simulation facility in Dallas, Tex., were scheduled to begin in October.

• 1963 June 30 - Two portable life support systems to be stowed in the Apollo LEM and one in the CM - Program: Apollo.
  MSC reported that two portable life support systems would be stowed in the LEM and one in the CM. Resupplying water, oxygen, and lithium hydroxide could be done in a matter of minutes; however, battery recharging took considerably longer, and detailed design of a charger was continuing.

• 1963 June 30 - Grumman completed the Apollo LEM circuit design for suit and cabin pressure control systems - Program: Apollo.
  Grumman completed the LEM circuit design for suit and cabin pressure control systems. Also the contractor formulated a detailed plan for the evaluation of red and white cockpit lighting; equipment for the test had already been received.

• 1963 July 3 - STL go-ahead to develop a parallel descent engine for the Apollo LEM - Program: Apollo.
  Space Technology Laboratories received Grumman's go-ahead to develop the parallel descent engine for the LEM. At the same time, Grumman ordered Bell Aerosystems Company to proceed with the LEM ascent engine. The contracts were estimated at $18,742,820 and $11,205,415, respectively.

• 1963 July 16 - Extendable boom for Apollo docking - Program: Apollo.
  MSC directed North American to concentrate on the extendable boom concept for CSM docking with the LEM. The original impact type of docking had been modified:
  1. The primary mode employed an extendable probe. It would establish initial contact and docking at a separation distance sufficient to prevent dangerous impact as a result of pilot error.
  2. The backup mode consisted of free-flying the two modules together. Mean relative impact velocities established during free-flying docking simulation studies would be used as the design impact velocities.
  North American and Grumman began a hardware testing and flight simulation program in late September to evaluate the feasibility of several types of extendable probe tether systems. The two companies were to determine the stiffness required of the docking structure for compatibility with the stabilization and control system.

• 1963 July 16 - Study on Apollo LEM visibility - Program: Apollo.
  Grumman presented the results of a study on LEM visibility. A front-face configuration with triangular windows was tentatively accepted by MSC for the ascent stage. Further investigation would be directed toward eliminating the "dead spots" to improve the configuration's visibility.

• 1963 July 18 - Pratt and Whitney to develop fuel cells for the Apollo LEM - Program: Apollo.
  Grumman selected Pratt and Whitney to develop fuel cells for the LEM. Current LEM design called for three cells, supplemented by a battery for power during peak consumption beyond what the cells could deliver. Grumman and Pratt and Whitney completed contract negotiations on August 27, and MSC issued a letter go-ahead on September 5. Including fees and royalties, the contract was worth $9.411 million.

• 1963 July 18 - Apollo portable life support system (PLSS) to have three attaching points for stowage - Program: Apollo.
  North American, Grumman, and Hamilton Standard, meeting at MSC with Crew Systems Division engineers, agreed that the portable life support system (PLSS) would have three attaching points for stowage in the spacecraft. In addition, it was agreed that the PLSS should not be used for shoulder restraint in the LEM.

• 1963 July 19 - Marquardt begins development of the Apollo LEM reaction control thrusters - Program: Apollo.
  Grumman directed the Marquardt Corporation to begin development of the LEM reaction control system thrusters. Negotiations had begun on March 11 on the definitive subcontract, a cost-plus-incentive-fee type with a total estimated cost of $10,871,186.

• 1963 July 23 - Hamilton Standard began development of the ECS for the Apollo LEM - Program: Apollo.
  Grumman authorized Hamilton Standard to begin development of the environmental control system (ECS) for the LEM. The cost-plus-incentive-fee contract was valued at $8,371,465. The parts of the ECS to be supplied by Hamilton Standard were specified by Grumman.

• 1963 July 28 - Grumman to design identical connectors for both ends of the space suit hoses in the Apollo LEM - Program: Apollo.
  ASPO ordered Grumman to design identical connectors for both ends of the space suit hoses in the LEM. This arrangement, called the "buddy concept," would permit one portable life support system to support two crewmen and thus would eliminate the need for a special suit-to-suit hose.

• 1963 July 30 - Installation of the inertial measurement unit and optical telescope in the Apollo LEM discussed - Program: Apollo.
  MIT and Grumman representatives discussed installing the inertial measurement unit and the optical telescope in the LEM. Of several possible locations, the top centerline of the cabin seemed most promising. Grumman agreed to provide a preliminary structural arrangement of the guidance components so that MIT could study problems of installation and integration.

• 1963 August 1 - Three methods of Apollo descent from lunar parking orbit reviewed - Program: Apollo.
  North American, NASA, and Grumman representatives discussed three methods of descent from lunar parking orbit:
  1. descent of the LEM only (the minimum energy Hohmann transfer),
  2. the combined descent of both spacecraft, and
  3. the synchronous equal period method.
  While neither contractor felt that weight factors should be of primary concern, Grumman favored the Hohmann transfer and North American the combined descent, which represented the extremes of energy requirements. After considering reliability, fuel consumption, and operational flexibility, NASA chose the synchronous method as the prime mission mode but recommended continued investigation of the other two techniques.

• 1963 August 2 - Grumman to design the LEM to have a thrusting capability with the Apollo CSM attached - Program: Apollo. Launch Vehicle: Saturn V.
  North American asked MSC if Grumman was designing the LEM to have a thrusting capability with the CSM attached and, if not, did NASA intend to require the additional effort by Grumman to provide this capability. North American had been proceeding on the assumption that, should the service propulsion system (SPS) fail during translunar flight, the LEM would make any course corrections needed to ensure a safe return trajectory. Additional Details: Grumman to design the LEM to have a thrusting capability with the Apollo CSM attached.

• 1963 August 15 - Increased Apollo LEM mission energy requirement - Program: Apollo.
  At a meeting on the LEM electrical power system, Grumman presented its latest load analysis, which placed the LEM's mission energy requirements at 76.53 kilowatt-hours. The control energy level for the complete LEM mission had been set at 54 kilowatt-hours and the target energy level at 47.12 kilowatt-hours. Grumman and MSC were jointly establishing ground rules for an electrical power reduction program.

• 1963 August 22 - Ad Hoc Rendezvous Working Group formed - Program: Apollo.
  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 August 26 - MSC received proposals for the visual displays for the Apollo LEM simulator - Program: Apollo.
  MSC received proposals for the visual displays for the LEM simulator. Because of the changed shape of that vehicle's windows, however, Grumman had to return those proposals to the original bidders, sending revised proposals to MSC in December. Farrand Optical Company was selected to develop the display, and the Center approved Grumman's choice. Negotiations between Grumman and Farrand were completed during March 1964.

• 1963 August 27 - Apollo LEM crew systems meeting - Program: Apollo.
  A LEM crew systems meeting was held at Grumman. The standing arrangement proposed for the crew promised to reduce the weight of the LEM by as much as 27.2 kilograms (60 pounds), and would improve crew mobility, visibility, control accessibility, and ingress-egress. Pending more comprehensive analysis, crew systems designers also favored the revised front-face configuration.

• 1963 August 31 - Full-scale cardboard model of the Apollo LEM - Program: Apollo.
  Grumman built a full-scale cardboard model of the LEM to aid in studying problems of cockpit geometry, specifically the arrangement of display panels. This mockup was reviewed by MSC astronauts and the layout of the cockpit was revised according to some of their suggestions.

  Also Grumman reported that a preliminary analysis showed the reaction control system plume heating of the LEM landing gear was not a severe problem. (This difficulty had been greatly alleviated by the change from five to four landing legs on the vehicle.

• 1963 August 31 - Apollo LEM test articles LTA-8 and LTA-9 - Program: Apollo.
  At a meeting at MSC, Grumman representatives submitted the cost proposal for LEM test articles LTA-8 and LTA-9, and suggested a testing program for the two vehicles: LTA-8 should be used for restrained integrated systems testing in the altitude propulsion test facilities at the Atlantic Missile Range; LTA-9 should be used for manned atmospheric tethered operation tests. The contractor also recommended an early flight demonstration program to verify the helicopter tether operation potential, which promised greatly increased mission test capability over fixed-base tether facilities. The tether method (helicopter or fixed- base) should be determined after the verification. LTA-8 should be considered as a constraint to LEM-5, and LTA-9 as a constraint to the lunar landing mission.

• 1963 September 5 - Study to define the stability limits of a 4.57 m radius Apollo LEM gear configuration - Program: Apollo.
  MSC began a study to define the stability limits of a 457-centimeter (180inch) radius LEM gear configuration. The study, in two phases, sought to examine factors affecting stability (such as lunar slope, touchdown velocity and direction, and the effects of soil mechanics) in direct support of the one-sixth model and full-scale drop test programs and to complete definition of landing capabilities of the LEM.

• 1963 September 16 - Inspection of first Apollo LEM ascent stage mockup - Program: Apollo.
  NASA representatives held a formal review of Grumman's LEM M-1 mockup, a full-scale representation of the LEM's crew compartment. MSC decided that (1) the window shape (triangular) and visibility were satisfactory; (2) a standing position for the crew was approved, although, in general, it was believed that restraints restricted crew mobility; (3) the controllers were positioned too low and lacked suitable arm support for fine control; and (4) crew station arrangement was generally acceptable, although specific details required further study.

• 1963 September 17 - LTV presented the preliminary results of a manual rendezvous simulation study - Program: Apollo.
  LTV presented the preliminary results of a manual rendezvous simulation study. Their studies indicated that a pilot trained in the technique could accomplish lunar launch and rendezvous while using only two to three percent more fuel than the automatic system.

• 1963 September 19 - Apollo space suit umbilical disconnects redesigned for interchangeability - Program: Apollo.
  The space suit umbilical disconnects were being redesigned to the "buddy concept" and for interchangeability between the CM and the LEM. MSC was reviewing methods for a crewman to return to the LEM following space suit failure on the lunar surface.

• 1963 September 19 - Ablative nozzle primary design for Apollo LEM's ascent engine - Program: Apollo.
  Grumman directed Bell Aerosystems Company to establish the ablative nozzle extension as the primary design for the LEM's ascent stage engine. The radiation-cooled nozzle design, a weight-saving alternative, must be approved by NASA.

• 1963 September 25 - Program reviewed for thermal testing for the Apollo LEM - Program: Apollo.
  MSC representatives reviewed Grumman's program for thermal testing for the LEM, to be conducted with the test model 2 (TM-2) vehicle. Because the vehicle's configuration had changed so extensively, the Center canceled the currently planned TM-2 ascent stage and ordered another stage to be substituted. TM-2's descent stage needed only small design changes to make it suitable for the program.

• 1963 September 26 - Apollo LEM electrical power system changes recommended - Program: Apollo.
  At a meeting at MSC, Grumman representatives presented 18 configurations of the LEM electrical power system, recommending a change from three to two fuel cells, still supplemented by an auxiliary battery system, with continued study on tankage design. On December 10, ASPO authorized the contractor to proceed with this configuration.

• 1963 September 26 - Apollo mission plans - Program: Apollo. Launch Vehicle: Saturn I.
  OMSF, MSC, and Bellcomm representatives, meeting in Washington, D.C., discussed Apollo mission plans: OMSF introduced a requirement that the first manned flight in the Saturn IB program include a LEM. ASPO had planned this flight as a CSM maximum duration mission only.
  • Bellcomm was asked to develop an Apollo mission assignment program without a Saturn I.
  • MSFC had been asking OMSF concurrence in including a restart capability in the S-IVB (second) stage during the Saturn IB program.
  ASPO would agree to this, but only if the H-1 engine were uprated from 85,275 to 90,718 kilograms (188,000 to 200,000 pounds) of thrust, resulting in a 907-kilogram (2,000-pound) payload gain.

• 1963 September 26 - Evaluation of the Apollo space suit integration into the LEM - Program: Apollo.
  MSC representatives visited Grumman for a preliminary evaluation of the Apollo space suit integration into the LEM. A suit failure ended the exercise prematurely. Nonetheless, leg and foot mobility was good, but the upper torso and shoulder needed improvement.

  On October 11, MSC Crew Systems Division (CSD) tested the suit's mobility with the portable life support system (PLSS). CSD researchers found that the PLSS did not restrict the wearer's movement because the suit supported the weight of the PLSS. Shifts in the center of gravity appeared insignificant. The PLSS controls, because of their location, were difficult to operate, which demanded further investigation.

• 1963 September 26 - Portable life support system in the Apollo CM be deleted - Program: Apollo.
  North American recommended that the portable life support system in the CM be deleted. Current planning placed two units in the LEM and one in the CM.

• 1963 September 30 - Interrelationships between all major Apollo LEM test vehicles clarified - Program: Apollo.
  The interrelationships between all major LEM test vehicles, including all test constraints and documentation requirements, were developed. This logic study, prepared by Grumman and forwarded to MSC, stressed the feasibility of alterations in the LEM test program as needed.

• 1963 October 2 - Preliminary configuration freeze for the Apollo LEM-adapter arrangement - Program: Apollo. Launch Vehicle: Saturn V.
  At a LEM Mechanical Systems Meeting in Houston, Grumman and MSC agreed upon a preliminary configuration freeze for the LEM-adapter arrangement. The adapter would be a truncated cone, 876 centimeters (345 inches) long. The LEM would be mounted inside the adapter by means of the outrigger trusses on the spacecraft's landing gear. This configuration provided ample clearance for the spacecraft, both top and bottom (i.e., between the service propulsion engine bell and the instrument unit of the S-IVB).

  At this same meeting, Grumman presented a comparison of radially and laterally folded landing gears (both of 457-centimeter (180-inch) radius). The radial-fold configuration, MSC reported, promised a weight savings of 22-2 kilograms (49 pounds). MSC approved the concept, with an 876-centimeter (345-inch) adapter. Further, an adapter of that length would accommodate a larger, lateral fold gear (508 centimeters (200 inches)), if necessary. During the next several weeks, Grumman studied a variety of gear arrangements (sizes, means of deployment, stability, and even a "bending" gear). At a subsequent LEM Mechanical Systems Meeting, on November 10, Grumman presented data (design, performance, and weight) on several other four-legged gear arrangements - a 457-centimeter (180-inch), radial fold "tripod" gear (i.e., attached to the vehicle by three struts), and 406.4-centimeter (160-inch) and 457-centimeter (180-inch) cantilevered gears. As it turned out, the 406.4-centimeter (160-inch) cantilevered gear, while still meeting requirements demanded in the work statement, in several respects was more stable than the larger tripod gear. In addition to being considerably lighter, the cantilevered design offered several added advantages:

  • A reduced stowed height for the LEM from 336.5 to 313.7 centimeters (132.5 to 123.5 inches).
  • A shorter landing stroke (50.8 instead of 101.6 centimeters) (20 instead of 40 inches).
  • Better protection from irregularities (protuberances) on the surface.
  • An alleviation of the gear heating problem (caused by the descent engine's exhaust plume).
  • Simpler locking mechanisms.
  • A better capability to handle various load patterns on the landing pads.
  Because of these significant (and persuasive) factors, MSC approved Grumman's change to the 406.4- centimeter (160-inch) cantilevered arrangement as the design for the LEM's landing gear. By mid- November, MSC reported to OMSF that Grumman was pursuing the 406.4-centimeter (160-inch) cantilevered gear. Although analyses would not be completed for some weeks, the design was "shown . . . to be the lightest gear available to date. . . . Tentative estimates indicate a gear stowed height reduction of about 9" (22.9 centimeters), which will still accommodate the 180" (45.7 centimeter) cantilever or 200" (508-centimeter) lateral fold gear as growth potential." Grumman's effort continued at "firming up" the design, including folding and docking mechanisms.

• 1963 October 8 - Tethered docking of the LEM and Apollo CSM - Program: Apollo.
  At MSC, the Spacecraft Technology Division reported to ASPO the results of a study on tethered docking of the LEM and CSM. The technology people found that a cable did not reduce the impact velocities below those that a pilot could achieve during free flyaround, nor was fuel consumption reduced. In fact, when direct control of the spacecraft was attempted, the tether proved a hindrance and actually increased the amount of fuel required.

• 1963 October 10 - Results of tests performed by astronauts in the Manned Space Flight Mission Simulator - Program: Apollo.
  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 16 - Commonality of displays and controls between Apollo CSM and LEM - Program: Apollo.
  MSC discussed commonality of displays and controls with its two principal spacecraft contractors. A review of panel components suggested that Grumman might use the same vendors as North American for such items as switches, potentiometers, and indicators.

• 1963 October 18 - Selection of five organizations for Apollo LEM guidance and navigation equipment - Program: Apollo.
  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.)

• 1963 October 23 - Systems and ground rules outlined for the Apollo lunar landing mission - Program: Apollo.
  MSC Flight Operations Division defined systems and outlined ground rules for the lunar landing mission. System definitions were: (1) primary, most efficient or economic; (2) alternate, either redundant (identical to but independent of the primary) or backup (not identical but would perform the same function); (3) critical (failure would jeopardize crew safety); (4) repairable (for which tools and spares were carried and which the crew could service in flight); and (5) operational, which must be working to carry out a mission.

  Mission rules established crew safety as the major consideration in all mission decisions and detailed actions to be taken in the event of a failure in any system or subsystem.

• 1963 October 23 - Contract to Hughes for a study of backup high gain antenna for Apollo LEM lunar surface equipment - Program: Apollo.
  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 October 24 - Apollo LEM landing site selection studied - Program: Apollo.
  Because OMSF had requested OSSA to provide lunar surface microrelief and bearing strength data to support LEM landing site selection and to permit LEM landing-gear design validation, the Ad Hoc Working Group on Follow-On Surveyor Instrumentation met at NASA Headquarters. Attending were Chairman Verne C. Fryklund, Clark Goodman, Martin Swetnick, and Paul Brockman of the NASA Office of Space Sciences and Applications; Harry Hess and George Derbyshire of the National Acadamy of Sciences; Dennis James of Bellcomm (for OMSF); and Milton Beilock of the Jet Propulsion Laboratory (JPL). The group proposed "a fresh look at the problem of instrumenting payloads of Surveyor spacecraft that may follow the currently approved developmental and operational flights, so that these spacecraft will be able to determine that a particular lunar site is suitable for an Apollo landing." The study was assigned to JPL.

• 1963 October 25 - Apollo LEM manned environmental control system development tests scheduled - Program: Apollo.
  MSC directed Grumman to schedule manned environmental control system (ECS) development tests, using a welded-shell cabin boilerplate and air lock. At about the same time, the company was also requested to quote cost and delivery schedule for a second boilerplate vessel, complete with prototype ECS. Although this vessel would be used by the MSC Crew Systems Division for in-house investigation and evaluation of ECS development problems, its major purpose was to serve as a tool for trouble-shooting during the operational phase.

• 1963 November 1 - Major reorganization of NASA - Program: Apollo. Launch Vehicle: Saturn I, Saturn V.
  NASA Associate Administrator for Manned Space Flight George E. Mueller notified the Directors of MSC, MSFC, and LOC that he intended to plan a flight schedule which would have a good chance of being met or exceeded. To this end, he directed that "all-up" spacecraft and launch vehicle tests be started as soon as possible; all Saturn IB flights would carry CSM and CSM LEM configurations; and two successful unmanned flights would be flown before a manned mission on either the Saturn IB or Saturn V.

  On November 18, Mueller further defined the flight schedule planning. Early Saturn IB flights might not be able to include the LEM, but every effort must be made to phase the LEM into the picture as early as possible. Launch vehicle payload capability must be reached as quickly as practicable. Subsystems for the early flights should be the same as those intended for lunar missions. To conserve funds, the first Saturn V vehicle would be used to obtain reentry data early in the Saturn test program.

  By December 31 the official schedule showed:

  Final Saturn I flight (SA-10):

  June 1965

  First Saturn IB flight (SA-201):

  first quarter, 1966

  First manned Saturn IB flight:

  either SA-203, third quarter of 1966, or SA-207, third quarter of 1967

  First Saturn V flight (SA-501):

  first quarter, 1967

  First manned Saturn V flight:

  either SA-503, third quarter of 1967, or SA-507, second quarter of 1968.

• 1963 November 8 - Go-ahead to RCA to develop the Apollo LEM radar - Program: Apollo.
  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.

• 1963 November 12 - Evaluation of propellant feed systems for the Apollo LEM ascent stage - Program: Apollo.
  ASPO reviewed Grumman's evaluation of series and parallel propellant feed systems for the LEM ascent stage. Because of the complications involved in minimizing propellant residuals in a parallel system, a series feed appeared preferable, despite an increase in LEM structural weight. Further study of the vehicle showed the feasibility of a two-tank configuration which would be lighter and have about the same propellant residual as the four-tank series-feed arrangement.

• 1963 November 13 - Means for reducing the weight of the Apollo LEM - Program: Apollo.
  After careful study, Grumman proposed to MSC 15 possible means for reducing the weight of the LEM. These involved eliminating a number of hardware items in the spacecraft; two propellant tanks in the vehicle's ascent stage and consequent changes in the feed system; two rather than three fuel cells; and reducing reaction control system propellants and, consequently, velocity budgets for the spacecraft. If all these proposed changes were made, Grumman advised, the LEM could be lightened significantly, perhaps by as much as 454 kilograms (1000 pounds).

• 1963 November 21 - Apollo subcontract with Rocketdyne for the LEM descent engine - Program: Apollo.
  MSC approved Grumman's $19,383,822 cost-plus-fixed-fee subcontract with Rocketdyne for the LEM descent engine development program.

• 1963 November 22 - 10 lunar landing areas recommended for the Apollo program - Program: Apollo.
  MSC's Space Environment Division (SED) recommended (subject to reconnaissance verification) 10 lunar landing areas for the Apollo program:
  1. 36 degrees 55' E. 1 degree 45' N.
  2. 31 degrees E. 0 degrees N.
  3. 28 degrees 22' E. 1 degree 10' N.
  4. 24 degrees 10' E. 0 degrees 10' N.
  5. 12 degrees 50' E. 0 degrees 20' N.
  6. 1 degree 28'W. 0 degrees 30' S.
  7. 13 degrees 15' W. 2 degrees 45' N.
  8. 28 degrees 15' W. 2 degrees 45' N.
  9. 31 degrees 30' W. 1 degree 05' S.
  10. 41 degrees 30'W. 1 degree 10' S.
  SED chose these sites on the basis of regional slopes, surface texture and strength, landmarks, isolated features, and the size, shape, and position of the various areas. The list included several sites that the Division had designated earlier in the year.

• 1963 November 27 - Velocity budgets for the Apollo spacecraft reduced - Program: Apollo.
  ASPO Manager Joseph F. Shea asked NASA Headquarters to revise velocity budgets for the Apollo spacecraft. (Studies had indicated that those budgets could be reduced without degrading performance.) He proposed that the 10 percent safety margin applied to the original budget be eliminated in favor of specific allowances for each identifiable uncertainty and contingency; but, to provide for maneuvers which might be desired on later Apollo missions, the LEM's propellant tanks should be oversized.

  The ASPO Manager's proposal resulted from experience that had arisen because of unfortunate terminology used to designate the extra fuel. Originally the fuel budget for various phases of the mission had been analyzed and a 10 percent allowance had been made to cover - at that time, unspecified - contingencies, dispersions, and uncertainties. Mistakenly this fuel addition became known as a "10% reserve"! John P. Mayer and his men in the Mission Planning and Analysis Division worried because engineers at North American, Grumman, and NASA had "been freely 'eating' off the so-called 'reserve'" before studies had been completed to define what some of the contingencies might be and to apportion some fuel for that specific situation. Mayer wanted the item labeled a "10% uncertainty."

  Shea recommended also that the capacity of the LEM descent tanks be sufficient to achieve an equiperiod orbit, should this become desirable. However, the spacecraft should carry only enough propellant for a Hohmann transfer. This was believed adequate, because the ascent engine was available for abort maneuvers if the descent engine failed and because a low altitude pass over the landing site was no longer considered necessary. By restricting lunar landing sites to the area between ±5 degrees latitude and by limiting the lunar stay time to less than 48 hours, a one-half-degree, rather than two-degree, plane change was sufficient.

  In the meantime, Shea reported, his office was investigating how much weight could be saved by these propellant reductions.

• 1963 November 29 - Apollo mission plan development study - Program: Apollo.
  After a meeting with Grumman officials on November 27, ASPO directed the contractor to begin a Grumman-directed Apollo mission plan development study.

• 1963 November 30 - Apollo LEM tethered flight vehicle considered - Program: Apollo.
  MSC directed Grumman to halt work on LEM test article 9, pending determination of its status as a tethered flight vehicle. As a result, the proposed flight demonstration of the tether coupler, using an S-64A Skycrane helicopter, was canceled.

• 1963 December 2 - AiResearch to supply cryogenic storage tanks for the Apollo LEM electrical power system - Program: Apollo.
  Grumman selected AiResearch Manufacturing Company to supply cryogenic storage tanks for the LEM electrical power system. Final negotiations on the cost-plus-incentive-fee contract were held in June 1964.

  On this same date, Grumman concluded negotiations with Allison Division of General Motors Corporation for design and fabrication of the LEM descent engine propellant storage tanks (at a cost of $5,479,560).

• 1963 December 10 - Apollo LEM Little Joe II configuration aerodynamically unstable - Program: Apollo. Launch Vehicle: Little Joe II.
  As a result of wind tunnel tests, Langley Research Center researchers found the LEM Little Joe II configuration to be aerodynamically unstable. To achieve stability, larger booster fins were needed. However, bigger fins caused more drag, shortening the length of the flight. MSC was investigating the possibility of using more powerful rocket engines to overcome this performance degradation.

• 1963 December 16 - Redundant gimbal actuation system in the Apollo LEM's descent engine deleted - Program: Apollo.
  ASPO concurred in Grumman's recommendation to delete the redundant gimbal actuation system in the LEM's descent engine. A nonredundant configuration would normally require mission abort in case of actuator failure. Consequently, in making this change, Grumman must ensure that mission abort and the associated staging operation would not compromise crew survival and mission reliability.

• 1963 December 17 - Grumman proposed a two-tank ascent stage configuration for the Apollo LEM - Program: Apollo.
  Grumman proposed a two-tank ascent stage configuration for the LEM. On January 17, 1964, ASPO formally concurred and authorized Grumman to go ahead with the design. The change was expected to reduce spacecraft weight by about 45 kilograms (100 pounds) and would make for a simpler, more reliable ascent propulsion system. ASPO also concurred in the selection of titanium for the two propellant tanks.

• 1963 December 20 - Hamilton Standard contract for Apollo LEM environmental control system - Program: Apollo.
  MSC announced that Grumman and Hamilton Standard had signed an $8,371,465 definitive contract for the LEM environmental control system. A go-ahead had been issued to Hamilton Standard on July 23.

• 1963 December 21 - MSC defined the Apollo LEM terminal rendezvous maneuvers - Program: Apollo.
  MSC defined the LEM terminal rendezvous maneuvers. That phase of the mission would begin at a range of 9.3 kilometers (five nautical miles) from the CSM and terminate at a range of 152.4 meters (500 feet). Before rendezvous initiation, closing velocity should be reduced to 61 meters (200 feet) per second by use of the ascent engine. The reaction control system should be used exclusively thereafter.

• 1963 December 31 - Apollo television cameras for the LEM to be government-furnished - Program: Apollo.
  MSC decided to supply television cameras for the LEM as government-furnished items. Grumman was ordered to cease its effort on this component.

  Resizing of the LEM propulsion tanks was completed by Grumman. The cylindrical section of the descent tank was extended 34.04 millimeters (1.34 inches), for a total of 36.27 centimeters (14.28 inches) between the spherical end bells. The ascent tanks (two-tank series) were 1240.54 centimeters (48.84 inches) in diameter.

• 1963 December 31 - Ryan selected for Apollo landing radar - Program: Apollo.
  RCA, contractor to Grumman for the LEM rendezvous and landing radars, chose Ryan Aeronautical Company as vendor for the landing radar. The contract was signed March 16, 1964.

• 1964 January 3 - Apollo contractors joint report on spacecraft test plan - Program: Apollo.
  North American, Grumman, and MIT Instrumentation Laboratory summarized results of a six-week study, conducted at ASPO's request, on requirements for a Spacecraft Development Program. Purpose of the study was to define joint contractor recommendations for an overall development test plan within resource constraints set down by NASA. ASPO required that the plan define individual ground test and mission objectives, mission descriptions, hardware requirements (including ground support equipment), test milestones, and individual subsystem test histories.

  Intermediate objectives for the Apollo program were outlined: the qualification of a manned CSM capable of earth reentry at parabolic velocities after an extended space mission; qualification of a manned LEM both physically and functionally compatible with the CSM; and demonstration of manned operations in deep space, including lunar orbit. The most significant basic test plan objective formulated during the study was the need for flexibility to capitalize on unusual success or to compensate for unexpected difficulties with minimum impact on the program.

  Only one major issue in the test plan remained unresolved - lunar descent radar performance and actual lunar touchdown. Two possible solutions were suggested:

  1. Landing of an unmanned spacecraft. If this failed, however, there would be little or no gain, since there was not yet a satisfactory method for instrumenting the unmanned vehicle for necessary failure data. If the landing were successful, it would prove only that the LEM was capable of landing at that particular location.
  2. Designing the LEM for a reasonably smooth surface. This would avoid placing too stringent a requirement on the landing criteria to accommodate all lunar surface unknowns. A block change to the LEM design could then be planned for about mid-1966. By that time, additional lunar data from Ranger, Surveyor, and Lunar Orbiter flights would be available. The group agreed the second solution was more desirable.
  The contractors recommended:
  1. ASPO concur with the proposed plan as a planning basis for implementation;
  2. ASPO issue a Development Test Plan to all three contractors (preferably within 30 to 60-days);
  3. each contractor analyze the effect of the plan upon spacecraft, facility, and equipment contracts; and
  4. ASPO and the contractors conduct periodic reviews of the plan once it was formalized.
  In addition, the test plan should be coordinated with the lunar landing mission study, as well as development testing and systems engineering for the complete Apollo program.

  The complete findings of this joint study were contained in a five-volume report issued by North American and submitted to MSC early in February 1964. (This document became known informally as the "Project Christmas Present Report.")

• 1964 January 7 - Grumman to implement changes to space suit oxygen umbilical hoses - Program: Apollo.
  ASPO directed Grumman to implement a number of recommendations on space suit oxygen umbilical hoses discussed at a joint Grumman/North American meeting and forwarded to ASPO on December 4, 1963:
  1. adopt a design that would permit use of CM hose sets in the LEM after crew transfer;
  2. place connectors on short hoses permanently attached to the suit, because suit vision and arm mobility did not permit use of on-suit connectors;
  3. determine exact placement and hose angles to route the suit portable life support system umbilicals between the legs of the suit;
  4. build the "buddy concept" into the umbilical design by ensuring that one of the LEM hoses had valve and safety provisions; and
  5. design the CM and LEM oxygen hose umbilicals to be interchangeable. (MSC would select a contractor for the connectors.)

• 1964 January 8 - Apollo LEM translation and descent engine thrust controllers - Program: Apollo.
  MSC directed Grumman to integrate LEM translation and descent engine thrust controllers. The integrated controller would be lighter and easier to install; also it would permit simultaneous reaction control system translation and descent engine control. Grumman had predicted that such a capability might be required for touchdown.

• 1964 January 10 - Apollo LEM extravehicular suit telemetry and communications system review - Program: Apollo.
  The Flight Data Systems Branch of the Engineering and Development Directorate provided ASPO's Lunar Mission Planning Branch with information about the LEM extravehicular suit telemetry and communications system. No line of sight (LOS) communications were possible, and there would be no ground wave propagation and no atmospheric reflection. The link between astronaut and LEM would be limited to LOS of the two antennas, and surface activities by an extravehicular astronaut must be planned accordingly.

• 1964 January 14 - Criteria for redundancy of controls and d