Radioactive rare gases and tritium in lunar rocks and in the sample return container
Radioactive rare gases and tritium in Apollo 12 lunar rocks and in sample return container, noting relationship to solar flare event
Davis, R., Jr.↗
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Averaged pulse-shape measurements of radar sea return at near-vertical incidence
Airborne radar sea return averaged pulse shape measurements over various water surfaces, noting clear distinction between specular and scattered reflection components
Levanon, N.↗
Isotopic studies in returned lunar samples
Analysis of lunar soil samples returned by Apollo 11 and 12 flights are discussed. Isotopic studies of the rare gases from Apollo 11 flight lunar samples are presented. The lunar soil analyses indicated the following: (1) high concentrations of solar wind rare gases, (2) isotopic match between solar wind gases and gas components in gas-rich meteorites, and (3) rare gases attributable to spallation reactions induced in heavier nuclides by cosmic ray particles.
Alexander, E. C., Jr.↗
Asteroid (Flora and Eros) sample-return missions via solar electric propulsion
The characteristics and capabilities of solar electric propulsion for performing sample-return missions to the asteroids Flora and Eros are considered. Trajectory/payload analysis and mission design tradeoff options are emphasized.
Friedlander, A. L.↗
Characterization of dust on clear filter from returned Surveyor 3 television camera
Surveyor 3 landed on the moon in April 1967. Part of the spacecraft was returned to earth in November 1969 by the Apollo 12 astronauts. A stripping film containing dust removed from the camera light filter was received for study. The study involved the characterization of the dust; the results of the study are presented.
Robertson, D. M.↗
A study of system requirements for Phobos/Diemos missions. Volume 3: Phase 2 results, satellite sample return missions and satellite mobility concepts
The scientific objectives were considered for a Phobos/Deimos mission. The payloads for a minimum useful instrument complement were developed. The rationale for a sample return mission is discussed, along with the scientific constraints and requirements for the acquisition of samples.
Source record↗
The extrapolation of laboratory and aircraft radar sea return data to spacecraft altitudes
Laboratory measurements show that the spectra of capillary waves grow with wind speed over six orders of magnitude. The scatter in the data can be partially understood and predicted from a combination of turbulence theory, radar theory, and the small sample theory of statistical inference. When these results are applied to a prediction of the sea return values to be obtained by S193 on Skylab, it can be shown that the size of the illuminated patch effectively averages out the horizontal scales of gustiness, so that the measurement will correspond to the synoptic scale wind.
Pierson, W. J.↗
Performance evaluation of the two-inch return-beam vidicon three-camera subsystem.
A very-high resolution multispectral television camera system is being developed for NASA for use on the Earth Resources Technology Satellite (ERTS) program. There are three cameras in the system, each viewing the same area but operating in the blue-green, red and near-infrared spectral bands. In the laboratory the cameras' limiting resolution is 4500 TV lines over the 25 x 25-mm image format of the Return Beam Vidicon (RBV). Analysis of typical ERTS scenes shows that actual contrast ratios will be much lower than those of laboratory test targets. A model was developed to predict the resolving power performance of the RBV camera under realistic conditions. The methods used are applicable to all types of imaging systems. To verify the model, tests were conducted using the RBV camera, a laser-beam image reproducer and a series of AF tribar test patterns of known values of contrast. As a more graphic demonstration, simulated multispectral images were generated using color-IR photographs from Apollo 9.
Miller, B. P.↗
Chemical evidence relating to the origin of the returned lunar material.
The material returned on the Apollo 11 mission can be separated into four types on chemical as well as structural grounds. Two distinct crystalline rock types can be identified, which may have been formed during two separate magmatic events. The lunar soil and breccias (which are apparently impacted soil material) can be thought of as being composed of a crystalline rock component similar in composition to, but differing in detail from, the two types of Apollo 11 crystalline rocks, and anorthositic component amounting to about 20% in the lunar soil, and a meteoritic component resembling carbonaceous chondrites in composition. Data on Ga, Ge, In, Ir, and Au in Apollo 11 rocks reflect the high temperature history of the lunar surface material, and the presence of a meteoritic component in the soil and breccias.
Baedecker, P. A.↗
Terrestrial quarantine considerations for unmanned sample return missions
For the purpose of understanding some of the possible implications of a terrestrial quarantine constraint on a mission and for developing a basic approach which can be used to demonstrate compliance beyond that developed for Apollo, a terrestrial quarantine study was performed. It is shown that some of the basic tools developed and used by the planetary quarantine community have applicability to terrestrial quarantine analysis. By using these tools, it is concluded that: (1) the method of biasing the earth aiming point when returning from the planet is necessary but, by itself, may not satisfy terrestrial quarantine constraints; and (2) spacecraft and container design significantly influence contamination transfer.
Hoffman, A. R.↗
Two-inch Return Beam Vidicon (RBV) multispectral three camera subsystem
A return beam vidicon multispectral three camera subsystem was developed and built as one of the two principal sensor payloads for the ERTS-A and -B missions. The performance of the cameras on ERTS-1 has been excellent, meeting or exceeding all expectations, especially in the area of geometric fidelity and stability. The three cameras are coaligned in the spacecraft to view the same square ground scene but in different spectral bands. When the separate images are processed and superimposed in their respective colors, they provide a single false color image containing the radiometric and cartographic information required for the ERTS system. The three spectral regions covered by the RBV subsystem are the blue-green red, and the near infrared. The three cameras are exposed simultaneously to facilitate registration of the three separate images into the final color composite.
Weinstein, O.↗
Returned lunar sample analysis
Studies on returned lunar samples are reported that emphasize the origin of the various lunar rocks. A heterogeneous accretion model and an igneous differention model are formulated and considered for the following three types of rocks: the iron rich basalts filling the mare basins; the KREEP basalts in Mare Imbrium and Oceanus Procellarum; and the anorthositic suite of the highlands.
Philpotts, J. A.↗
Sedimentology of clastic rocks returned from the moon by Apollo 15.
A petrographic study of eleven samples of clastic rock returned from the moon by Apollo 15 suggests that two lithologies are present. The distinction between the two lithologies is based on the glass content of the rock matrices and the morphology of the detrital particles. Group I rocks have abundant, glass-rich, porous matrices and glass particles with morphologies comparable to those of glass particles in the lunar soil. The group I rocks were probably formed by welding or sintering of surficial soil deposits by impact-generated base surges of limited extent. Group II rocks have an essentially mineralic matrix and have an abundance of rounded mineral grains. Sample 15455 is the only Apollo 15 sample assigned to this group. In its general textural features, sample 15455 is comparable with the group II rocks from the Fra Mauro Formation at the Apollo 14 site. Textural features such as shock modification and rounding of mineral grains suggest that this sample is the product of a large-scale impact-generated base surge which possibly resulted from the Imbrian event.
Lindsay, J. F.↗
Analyses of the returned lunar surface fines for porphyrins.
Apollo 11, 12, and 14 lunar surface fines were examined for the presence of porphyrins by a sensitive fluorescent technique. The returned lunar samples studied were of bulk fines collected from the Sea of Tranquillity by Apollo 11, from the Ocean of Storms by Apollo 12, and from the nonmare Fra Mauro formation by Apollo 14. It was found that no porphyrins are present in lunar surface fines which have been extensively irradiated and sorted.
Rho, J. H.↗
Airline return-on-investment model for technology evaluation
This report presents the derivation, description, and operating instructions for a computer program (TEKVAL) which measures the economic value of advanced technology features applied to long range commercial passenger aircraft. The program consists of three modules; and airplane sizing routine, a direct operating cost routine, and an airline return-on-investment routine. These modules are linked such that they may be operated sequentially or individually, with one routine generating the input for the next or with the option of externally specifying the input for either of the economic routines. A very simple airplane sizing technique was previously developed, based on the Brequet range equation. For this program, that sizing technique has been greatly expanded and combined with the formerly separate DOC and ROI programs to produce TEKVAL.
Source record↗
Radar signal return from near-shore surface and shallow subsurface features, Darien Province, Panama
The AN/APQ-97 radar imagery over eastern Panama is analyzed. The imagery was directed toward extraction of geologic and engineering data and the establishment of operational parameters. Subsequent investigations emphasized landform identification and vegetation distribution. The parameters affecting the observed return signal strength from such features are considered. Near-shore ocean phenomena were analyzed. Tidal zone features such as mud flats and reefs were identified in the near range, but were not detectable in the far range. Surface roughness dictated the nature of reflected energy (specular or diffuse). In surf zones, changes in wave train orientation relative to look direction, the slope of the surface, and the physical character of the wave must be considered. It is concluded that the establishment of the areal extent of the tidal flats, distributary channels, and reefs is practical only in the near to intermediate range under minimal low tide conditions.
Hanson, B. C.↗
Electric radiation fields of lightning return strokes in three isolated Florida thunderstorms
Peak value and risetime distributions for the electric radiation fields produced by lightning strokes to ground in three isolated Florida thunderstorms are presented. The storm at 195 km produced about 1000 return strokes having an average peak radiation field (normalized to 100 km) of about 5.5 V/m, the storm at 110 km produced about 700 strokes having 2.0 V/m, and the storm within 10 km produced about 100 strokes having 15.0 V/m. For each storm the average peak radiation field for first strokes was only slightly greater than the average peak field for subsequent strokes. For the sample of three storms the average peak radiation field in a given storm was proportional to the number of subsequent strokes per flash in that storm. The field risetimes for the two distant storms have statistical properties which are essentially identical to those reported for distant storms in Pennsylvania, whereas the close Florida storm exhibited significantly faster risetimes.
Lin, Y. T.↗
Preliminary data on lunar surface material returned by Luna 16 automatic station
Results of preliminary investigations of a sample of lunar surface material returned by Luna 16 automatic station are reported. Information on the granulometric characteristics of regolith, its optical properties, types of its constituent rocks, and its mineral composition is given. The chemical composition of major and trace elements for different sections of the core and for the lunar basalt was determined. Isotopic composition of inert gases and of several elements was studied. The Rb/Sr age was determined at 4.85 to 4.25 billion years.
Vinogradov, A. P.↗