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Photographic analysis of track and secondary impact craters from blocks and boulders to determine lunar surface mechanical properties
Estimates were made of the accuracy of reference point grids using the technique of calculating the errors from theoretical analysis. Factors taken into consideration were: telescope accuracy, number of photographs, and libration amplitude. To solve the problem, formulas were used for the relationship between the coordinates of lunar surface points and their images on the photograph.
Among the hazards that must be negotiated by lunar-landing spacecraft are blocks on the surface of the Moon. Unfortunately, few data exist that can be used to evaluate the threat posed by such blocks to landing spacecraft. Perhaps the best information is that obtained from Surveyor photographs, but those data do not extend to the dimensions of the large blocks that would pose the greatest hazards. Block distributions in the vicinities of the Surveyor 1, 3, 6, and 7 sites have been determined from Lunar Orbiter photography and are presented here. Only large (i.e., greater than or equal to 2.5 m) blocks are measurable in these pictures, resulting in a size gap between the Surveyor and Lunar Orbiter distributions. Nevertheless, the orbital data are self-consistent, a claim supported by the similarity in behavior between the subsets of data from the Surveyor 1, 3, and 6 sites and by the good agreement in position (if not slopes) between the data obtained from the Surveyor 3 photography and those derived from the Lunar Orbiter photographs. Confidence in the results is also justified by the well-behaved distribution of large blocks at the surveyor site. Comparisons between the Surveyor distributions and those derived from the orbital photography permit these observations: (1) in all cases but that for Surveyor 3, the density of large blocks is overestimated by extrapolation of the Surveyor-derived trends; (2) the slopes of the Surveyor-derived distributions are consistently lower than those determined for the large blocks; and (3) these apparent disagreements could be mitigated if the overall shapes of the cumulative lunar block populations were nonlinear, allowing for different slopes over different size intervals. The relatively large gaps between the Surveyor-derived and Orbiter-derived data sets, however, do not permit a determination of those shapes.
Tracking data for Lunar Orbiter I producing first estimate of overall gravitational field of Moon, noting spacecraft will not impact on Moon before completing photographic mission
Depth of lunar dust estimated by comparison with laboratory craters overlain by various thicknesses of sand, including Ranger VII photographs
Size-frequency and spatial distributions of small craters on moon from Ranger Block III PHOTOGRAPHS
Astrogeologic studies - lunar and planetary research
Improved rapid processing methods for handling large amounts of photoclinometric data, and maximizing ratio of work done by computer relative to manual reduction
Lunar Orbiter 2 spacecraft high resolution photographs used to study rolling boulders on moon, noting tracks on crater walls
Lunar geology based on Apollo 14 photographs and soil and rock samples
Surveyor 3 spacecraft attitude change on lunar surface, examining Apollo 12 mission photographs
The Apollo 16 flight is described. The objectives, lunar surface activites, lunar orbital experiments, service module orbital photographic tasks, and command module photographic tasks are discussed.
An index is provided to representative photographs and transparencies available from NASA. Subjects include spacecraft, astronauts, lunar surface, planets and outer space phenomena, earth observations, and aviation. High altitude aircraft infrared photographs are included along with artists' conceptions of space shuttle and space colonies.
Young lunar impact structures were investigated by using lunar orbiter, Apollo Metric and panorama photographs. Measurements on particularly homogeneous areas low in secondary craters made possible an expansion of primary crater distribution to small diameters. This is now sure for a range between 20m or = D or = 20km and this indicates that the size and velocity distribution of the impacting bodies in the last 3 billion years has been constant. A numerical approximation in the form of a 7th degree polynomial was obtained for the distribution.
The history of the NASA space program is traced, and future plans are outlined. Projects discussed include Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz, science-applications spacecraft (Ranger, Surveyor, Mariner, Pioneer, and Voyager), the Space Shuttle, the planned Space Station, orbital maneuvering vehicles, lunar bases, and planetary exploration. Numerous photographs and drawings are provided.
The current status of major NASA programs and planning efforts is surveyed. Consideration is given to space-sciences programs (IRAS, SIRTF, Space Telescope, and planetary probes), applications programs (terrestrial remote sensing, communication, and meteorology), manned spacecraft, the STS, the Space Station, space commercialization efforts (materials processing and bioprocessing), and the feasibility of permanent lunar bases and manned Mars expeditions. Photographs and drawings are included.
The eruptive history of mare basalts in the Orientale Basin has been studied, using Lunar Orbiter 4 high-resolution photographs, Zond 8 photographs, and recently acquired Galileo EM-1 multispectral images. This work represents a refined set of compositional data incorporating the use of a linear mixing model for mare compositions, crater count data, and a comprehensive morphologic analysis of Orientale Basin mare deposits. Evidence for multiple eruptive episodes has been found, with compositions ranging from medium- to high-Ti basalt (less than 4 to greater than 6 wt. percent TiO2). Eruptive styles included flood, rille-forming, and shield-forming eruptions. Impact crater densities of mare units in the Orientale Basin enable determination of the ages of these deposits, using the method of Neukum et al. Earliest eruptions of mare basalt in the basin occurred at greater than or equal to 3.80 Ga and the latest eruptions occurred at about 2.3-2.5 Ga. Hence, mare volcanism occurred over a period of nearly 1.5 Ga.
Strength of overlay of granular material on Moon estimated from Ranger VII photographs, showing fairly steep slopes covered with dust