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The Falmouth conference of 1965 made the first concerted effort to define a systematic 10-year program of lunar exploration, giving primary emphasis to manned exploration. Working groups were established in the disciplines of geodesy/cartography, geology, geophysics, bioscience, geochemistry (mineralogy and petrology), particles and fields, lunar atmosphere measurements, and astronomy. At the conclusion of the conference each disciplinary working group prepared a report, from which a summary was prepared by a coordinating committee. Following are excerpts from the summary, which set forth the major requirements for the program.*
*NASA 1965 Summer Conference on Lunar Exploration and Science, NASA SP-88 (Washington, 1965).
In this chapter the major recommendations of the Working Groups are arranged by missions or programs. The suggested priorities, instrument allocations, and mission characteristics for various vehicles are indicated briefly. . . .
Although there was some overlap, most of the recommendations could be divided into these missions: Apollo, Lunar Orbiter, Apollo Extension System-Manned Lunar Orbiter (AES-MLO), Apollo Extension System-Manned Lunar Surface (AES-MLS) and Post-AES.... As the scientific instruments and space vehicle characteristics and availability become more clearly defined, the assignment of experiments will become clearer.
The plans and recommendations of the 1965 Lunar Exploration Summer Conference are based on a 10-year program of exploration, beginning with the first manned lunar landing in the Apollo program. The recommendations of this conference are limited to the 10-year period following the first Apollo lunar landings because a decade seems to be the approximate maximum time for which developments can be meaningfully forecast. In addition, the long lead times involved in the development of equipment for use in space flight require that recommendations be made to cover this period of time. In carrying out these recommendations, it will be necessary for the National Aeronautics and Space Administration to conduct its programs in a way that permits a maximum degree of flexibility to meet changing requirements.
The need for flexibility is also important for determining the rate at which missions should be conducted during this ten-year period. It is clearly desirable to schedule flight missions to provide adequate time between missions to react to the findings of one mission by modifying experiments for a later mission. One method of accomplishing this is through the modular construction of individual experiments. It is also desirable to program certain types of experiments so that the time of the operation of the devices used on one mission will overlap with the operating time of devices operated on a subsequent mission. This will provide not only scientific continuity in the experiments, but also simultaneous data from a multiplicity of lunar locations.
In addition, overall program planning considerations dictate the scheduling of missions at relatively close intervals. It is clearly desirable to maintain a certain degree of program momentum, both for psychological reasons and to make certain that the project personnel analyzing the results are provided with definite goals over a relatively long period of time.
On consideration of all of these factors, it was the feeling of the Working Groups that the National Aeronautics and Space Administration should schedule lunar surface missions at a minimum rate of one per year or possibly two through 1974. Lunar orbital missions should be conducted at the rate of one per year. Since many of the lunar surface missions will require two flights each, three to five Apollo/Saturn V vehicles are required annually.
Present indications are that lunar exploration should continue at the same rate in the latter half of the 1970s. However, there seems to be no need now to plan the flight mission assignment schedule for that period of time.
It is assumed that at least the first missions, with durations limited to a day or two and with exploration limited to an area close to the point of landing, will be dominated by operational considerations. Since the highest mission priority is assigned to the safety of the astronauts, the bulk of their time and attention will be devoted to perfecting the procedures of flight. In the relatively short duration of these early missions, the time assigned to scientific lunar exploration as such will be limited.
All experiments should be designed to conserve the astronauts' time, the most valuable scientific commodity on the early missions.
As flight procedures and techniques are perfected, and as improved flight equipment becomes available, plans should be made to gradually increase the duration of stays on the Moon, the distance traveled from the point of landing, and the proportion of the astronauts' time devoted to lunar exploration. A judicious use of "manned" and "unmanned" spacecraft will be required to obtain maximum coverage. Recommendations were made by some groups concerning the specific instrumentation to be carried on each of the first three landings.
Training of the astronauts in sampling techniques and field geology is of the utmost importance to insure the intelligent collection of samples. To assure collection of sterile samples, training is required for the astronauts in the nature of contamination, transfer of contaminants, aseptic transfer procedures, and chemical cleanliness.
The highest priority activity for the early Apollo landings is to return the greatest number and variety of samples as is feasible. It is desirable that all samples be kept sterile and free of chemical contaminants from such sources as the LEM fuels, the LEM atmosphere or the outgassing or leakage of the astronaut's suit. A variety of easily obtainable samples should be collected, ranging from dust to rock sizes. These samples should be taken as far from the LEM as possible. Both surface and subsurface samples are required. In the event of a semiaborted or shortened stay on the lunar surface, the astronaut's first scientific duty is the collection of as many samples as possible, without regard to sterility.
The second priority for the Early Apollo is the emplacement of the Lunar Surface Experiment Package (LSEP) by the astronauts. This should be emplaced to attain optimum operating conditions. Next in priority are the lunar geological traverses by the astronauts. If feasible, these should be accurately controlled with automatic procedures and monitoring. The description of topographic and geologic relations along the traverse lines should be supplemented by stereoscopic photographs.
The working groups were asked to consider equipment priority beginning with the most important. Weights assigned are the absolute minimum needed to accomplish the task. In some cases (i.e., sample tools), added weight and complexity would be desirable if weight and space were available. This priority list is as follows:
Studies and tests should be started immediately to determine the amounts and effects of the outgassing of the astronauts' suits and the escape of the atmosphere from the LEM. Sterilization of the escaping atmosphere from the LEM should be considered. Analyses of the possible contaminants in the LEM fuel and the effects on sample collection should be undertaken.
Upon return of the lunar samples to Earth, they will be prepared at a Lunar Sample Receiving Laboratory (LSRL) for distribution. Here they will be logged in, cataloged, checked for outgassing, measured for low level radiation, and examined for pathogenic agents. Only those tests that must be done immediately will be conducted at the LSRL. The portion of samples to be distributed will be packaged and initial distribution to the selected scientific investigators will be made.
In the period before the end of the decade two classes of missions are scheduled.
These missions will begin in the period of 1966-1967. The primary function for the approved missions is site selection, and hence, low altitude orbiters are desirable. However, should particles and field experiments be included on later flights, altitudes of 150 to 2000 km are required. Following are some specific recommendations for inclusion on these flights:
Consideration should be given to the inclusion of simple diagnostic experiments to be conducted from the orbiting Command/Service Module (CSM) in conjunction with Apollo experiments on the lunar surface.
Since less than 1 percent of the lunar surface will be visited in the near future, a major source of scientific knowledge will come from orbiting spacecraft. Extensive information can be easily obtained for the following reasons:
For complete photographic coverage of the lunar surface the lunar Orbital Camera System should include the following camera subsystems:
Imaging sensors will provide information about surface structure and composition from depths of microns to a few meters. Imaging instruments, including UV [ultraviolet] imagers, IR [infrared] imagers, and high-resolution radars have proven value for surface and near-surface structure and composition studies and for the study of thermal anomalies. Coverage of the entire Moon with these instruments is recommended at an early date. Nonimaging remote sensors, such as the passive microwave, radar scatterometer, IR, X-ray. gamma-ray, and alpha-particle emission are recommended for inclusion in lunar orbital payloads pending the results of current remote sensor feasibility studies.
Atmospheric and ionospheric variability surveys should be conducted. The recommended characteristics of the ion and neutral mass spectrometers are described in the Group Report. Ion traps, solar wind detectors, and pressure gauges can be adapted from the unmanned programs.
Other experiments include the determination of the cosmic-ray albedo, the study of solar and lower-energy galactic cosmic rays (particle telescope), and the search for water using a neutron instrument to defect the hydrogen content of the surface.
There are three orbital instruments that have the potential of obtaining valuable data from depths of kilometers and beyond. The first of these is a magnetometer, which will yield important information on the geology of the lunar crust. Second is a gravity gradiometer yielding details of the variations in the lunar gravitational field. The third is the electromagnetic pulse probe, which has the potential for probing to depth and differentiating the various layers present.
The AES-MLS is essentially a continuation of the early Apollo missions characterized by longer stay time and larger scientific payloads.
It is suggested that this program can be usefully exploited in five or six missions, extending through 1974. The scientific requirements of this series include stay times up to 14 days and traverses up to 15 km from point of landing.
The longer stay time will probably permit the collection of more material than can be returned to Earth. Hence aids to the selection of samples in the field or prior to return should be provided by analytical equipment that will also measure sample characteristics that may be altered by return or packaging. Sample return is still the most significant achievement in these missions. Local mapping should also have a high priority so that sample location is accurately tied to the local geology.
The capability to off load several LSEP's during each AES mission is also an important aspect. In this way, a small array of stations (LSEP's) could be set into operation, giving important information for revealing the internal properties of the Moon.
The Moon should provide a unique base for astronomers because of its useful environmental characteristics, the most important being the lack of an appreciable atmosphere. However, exhaustive studies of the complete lunar environment are necessary before engineering design can be started.
The primary objective of analytical devices used on the lunar surface should be to extend the power of the observer to differentiate materials that have similar characteristics. The optimum sample return capability would be between 200 and 250 kg (450-600 lb.) per mission. The following basic types of equipment are required for this phase of lunar exploration:
To obtain maximum output of scientific information from these experiments, astronauts should be given scientific training in specific rather than general areas. The greatest need is for trained geologists; however, specialized training will be required in physics, meteorology, chemistry, and in other fields.
The AES should be followed by a program including long-distance travel, up to 800 km and fixed-site investigation from 2 months to 1 year. These missions should commence about 1975 and proceed at a rate of one per year through 1980. Additional orbital flights also appear desirable during this period so as to conduct simultaneous orbital and surface missions. A long-range laboratory vehicle for geological and geophysical exploration is required to permit the collection of data to form a broad regional integrated picture of the surface geology and crustal structure. These data will also be essential as a basis for interpretation of the imagery and measurements obtained from the remote sensing orbital vehicle and also to substantiate other investigations. A series of traverses along the geological belt is suggested, requiring a vehicle with the following characteristics:
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