A meeting to review the lunar orbit rendezvous (LOR) technique as a possible mission mode for Project Apollo was held at NASA Headquarters. Representatives from various NASA offices attended: Joseph F. Shea, Eldon W. Hall, William A. Lee, Douglas R. Lord, James E. O'Neill, James Turnock, Richard J. Hayes, Richard C. Henry, and Melvyn Savage of NASA Headquarters; Friedrich O. Vonbun of Goddard Space Flight Center (GSFC); Harris M. Schurmeier of Jet Propulsion Laboratory; Arthur V. Zimmeman of Lewis Research Center; Jack Funk, Charles W. Mathews, Owen E. Maynard, and William F. Rector of MSC; Paul J. DeFries, Ernst D. Geissler, and Helmut J. Horn of Marshall Space Flight Center (MSFC); Clinton E. Brown, John C. Houbolt, and William H. Michael, Jr., of Langley Research Center; and Merrill H. Mead of Ames Research Center. Each phase of the LOR mission was discussed separately.
The launch vehicle required was a single Saturn C-5, consisting of the S-IC, S-II, and S-IVB stages. To provide a maximum launch window, a low earth parking orbit was recommended. For greater reliability, the two-stage-to-orbit technique was recommended rather than requiring reignition of the S-IVB to escape from parking orbit.
The current concepts of the Apollo command and service modules would not be altered. The lunar excursion vehicle (LEV), under intensive study in 1961, would be aft of the service module and in front of the S-IVB stage. For crew safety, an escape tower would be used during launch. Access to the LEV would be provided while the entire vehicle was on the launch pad.
Both Apollo and Saturn guidance and control systems would be operating during the launch phase. The Saturn guidance and control system in the S-IVB would be "primary" for injection into the earth parking orbit and from earth orbit to escape. Provisions for takeover of the Saturn guidance and control system should be provided in the command module. Ground tracking was necessary during launch and establishment of the parking orbit, MSFC and GSFC would study the altitude and type of low earth orbit.
The LEV would be moved in front of the command module "early" in the translunar trajectory. After the S-IVB was staged off the spacecraft following injection into the translunar trajectory, the service module would be used for midcourse corrections. Current plans were for five such corrections. If possible, a symmetric configuration along the vertical center line of the vehicle would be considered for the LEV. Ingress to the LEV from the command module should be possible during the translunar phase. The LEV would have a pressurized cabin capability during the translunar phase. A "hard dock" mechanism was considered, possibly using the support structure needed for the launch escape tower. The mechanism for relocation of the LEV to the top of the command module required further study. Two possibilities were discussed: mechanical linkage and rotating the command module by use of the attitude control system. The S-IVB could be used to stabilize the LEV during this maneuver.
The service module propulsion would be used to decelerate the spacecraft into a lunar orbit. Selection of the altitude and type of lunar orbit needed more study, although a 100-nautical-mile orbit seemed desirable for abort considerations.
The LEV would have a "point" landing (±½ mile) capability. The landing site, selected before liftoff, would previously have been examined by unmanned instrumented spacecraft. It was agreed that the LEV would have redundant guidance and control capability for each phase of the lunar maneuvers. Two types of LEV guidance and control systems were recommended for further analysis. These were an automatic system employing an inertial platform plus radio aids and a manually controlled system which could be used if the automatic system failed or as a primary system.
The service module would provide the prime propulsion for establishing the entire spacecraft in lunar orbit and for escape from the lunar orbit to earth trajectory. The LEV propulsion system was discussed and the general consensus was that this area would require further study. It was agreed that the propulsion system should have a hover capability near the lunar surface but that this requirement also needed more study.
It was recommended that two men be in the LEV, which would descend to the lunar surface, and that both men should be able to leave the LEV at the same time. It was agreed that the LEV should have a pressurized cabin which would have the capability for one week's operation, even though a normal LOR mission would be 24 hours. The question of lunar stay time was discussed and it was agreed that Langley should continue to analyze the situation. Requirements for sterilization procedures were discussed and referred for further study. The time for lunar landing was not resolved.
In the discussion of rendezvous requirements, it was agreed that two systems be studied, one automatic and one providing for a degree of manual capability. A line of sight between the LEV and the orbiting spacecraft should exist before lunar takeoff. A question about hard-docking or soft-docking technique brought up the possibility of keeping the LEV attached to the spacecraft during the transearth phase. This procedure would provide some command module subsystem redundancy.
Direct link communications from earth to the LEV and from earth to the spacecraft, except when it was in the shadow of the moon, was recommended. Voice communications should be provided from the earth to the lunar surface and the possibility of television coverage would be considered.
A number of problems associated with the proposed mission plan were outlined for NASA Center investigation. Work on most of the problems was already under way and the needed information was expected to be compiled in about one month.
(This meeting, like the one held February 13-15, was part of a continuing effort to select the lunar mission mode).
Deletion of non-critical equipment and improvement of existing systems reduced the weight of the command and service modules by 1,239 pounds, with a target reduction of 1,500 pounds.
Among the items deleted from the command module (CM) were exercise and recreation equipment, personal parachutes and parachute containers located in the couches, individual survival kits, solar radiation garments, and eight-ball displays. A telescope, cameras and magazines considered scientific equipment, and a television monitor were deleted from the CM instrumentation system.
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.
MSC advised North American that the television camera in the CM was being modified so that ground personnel could observe the astronauts and flight operations. Television images would be transmitted directly to earth via the Deep Space Instrumentation Facility.
MSC conducted a week-long salt spray test on the CM television camera's magnesium housing. This was necessitated by similar tests on the Leach data storage structure, which had disclosed the inadequacy of that equipment's nickel plating. The television camera, with its protective coating (AMS 2478, Dow 17 treatment), withstood the ordeal quite well. MSC therefore decided that the magnesium housing was acceptable.
NASA announced plans to install Apollo Unified S-Band System equipment at its Corpus Christi, Tex., tracking station. The Unified S-Band equipment included a 9-m (30-ft) diameter parabolic antenna and would enable handling of seven different types of communications with two different vehicles, the CM and the LEM. The communications would: track the spacecraft; command its operations and confirm that the command had been executed; provide two-way voice conversation with three astronauts; keep a continuous check on the astronauts' health; make continuous checks on the spacecraft and its functions; supply a continuous flow of information from the Apollo onboard experiments; and transmit television of the astronauts and the exploration of the moon.
In response to the March 30 memo from NASA Deputy Administrator Robert C. Seamans, Jr., regarding potential uses of TV on Apollo, Associate Administrator for Manned Space Flight George E. Mueller replied that ". . . we have been making a progressive review of the Apollo electronic systems. Performance and application of the Apollo TV system are being looked at as part of the review." He added that he expected to be in position by mid-May to discuss plans with Seamans in some detail.
Apollo Program Director Phillips wrote MSC ASPO Manager George Low, that "based on the excellent results of the color TV coverage on the Apollo 10 mission . . . I concur with your plan to carry and utilize a color TV camera in the Command Module for Apollo 11 and subsequent missions. . . ."