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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Surveyor Project Final Report: Part 1 - Project Description and Performance, Volume 2

The Surveyor Project planned and conducted seven unmanned lunar missions for which spacecraft were launched between May 1966 and January 1968. Each of the spacecraft was successfully launched with the then newly developed Atlas/Centaur vehicle which utilized for the first time a high-specific-impulse, liquid hydrogen/liquid oxygen fueled stage. Five of the spacecraft successfully soft-landed and returned a great quantity of engineering and scientific data on extensive postlanding operations, accomplishing all mission and project objectives. Four of the spacecraft soft-landed at selected mare sites to provide data which were required to support the Apollo Program. The final spacecraft was then successfully used for scientific investigation of a contrasting site in the rugged lunar highlands. Surveyor was a fully attitude-stabilized spacecraft designed to receive and execute a wide variety of earth commands, as well as to perform certain automatic functions including the critical terminal-descent and soft-landing sequences. Significant new and advanced subsystems that were developed and/or used in combination to enable Surveyor to execute the complex terminal phase of flight were: (1) a solid-propellant main retro motor, (2) throttlable liquid-propellant vernier engines (also used for midcourse velocity correction), (3) highly sensitive velocity- and altitude-sensing radars, and (4) an automatic closed-loop guidance and control system. The first Surveyor spacecraft carried a survey television camera which, together with other engineering instrumentation, obtained in-flight and postlanding data. The complement of instruments carried on later missions included various combinations of the following additional devices: (1) a soil mechanics/surface sampler instrument for picking, digging, and handling lunar surface material; (2) an alpha scattering instrument for performing a chemical analysis of the lunar surface material; and (3) magnets attached to the spacecraft for determining magnetic properties of the soil.

Jet Propulsion Laboratory↗
NASA NTRS1969

Surveyor results.

Surveyor lunar scientific payload and results, discussing TV camera, soil mechanics and surface sampler, alpha scattering instrument, small magnets and surface analysis

Hibbs, A. R.↗
NASA NTRS1969

Sampling.

Bulk, selective particulate and hard rock samplers for landed extraterrestrial geological and biological instruments performing on-site analysis

Hotz, G. M.↗
NASA NTRS1967

Surveyor 3 Preliminary Science Results

Surveyor III soft-landed on the Moon at 00:04 GMT on April 20, 1967. Data obtained have significantly increased our knowledge of the Moon. The Surveyor III spacecraft was similar to Surveyor I; the only major change in scientific instrumentation was the addition of a soil mechanics surface sampler. Surveyor III results at this preliminary evaluation of data give valuable information about the relation between the surface skin of under-dense material responsible for the photometric properties and the deeper layers of material whose properties resemble those of ordinary terrestrial soils. In addition, they provide new insight into the relation between the general lunar surface as seen by Surveyor I and the interior of a large subdued crater. The new results have also contributed to our understanding of the mechanism of downhill transport. Many critical questions cannot, however, be answered until final reduction of experimental data.

Source record↗
NASA NTRS1972

Services provided in support of the planetary quarantine requirements

Results are presented of laboratory experiments conducted on the thermal resistance of naturally occurring airborne spores and microbiological examinations of space hardware using long-term slit samplers and rodac plate and swab-rinse methods of sampling environmental surfaces.

Favero, M. S.↗
NASA NTRS1972

Evaluation of mechanisms returned from Surveyor 3

The mechanisms of the TV camera and surface sampler retrieved from the Surveyor 3 spacecraft during the Apollo 12 mission are discussed. Data are presented showing the performance of these mechanisms before and after operation for one lunar day and storage for 2-1/2 years on the surface of the moon. An analysis of the critical component materials is also given.

Jones, J. R.↗
NASA NTRS1972

Lunar surface: Changes in 31 months and micrometeoroid flux

A preliminary comparison of Surveyor 3 and Apollo 12 photographs of areas disturbed by the Surveyor is described. About 60 Surveyor pictures taken in April and May 1967 and 20 Apollo photographs including stereo pairs were examined in detail. Only one definite change in the surface, other than those produced by astronauts, was noted. This is a particle about 2 mm in diameter which appears in the Apollo photographs of a Surveyor footpad imprint but which does not appear in the Surveyor photographs. The walls made by Surveyor footpads and surface sampler were still in place, and surface areas darkened by ejected fines during the Surveyor landing still appeared dark. The absence of detectable craters in the footpad imprint implies a very low micrometeorite flux on the lunar surface.

Jaffe, L. D.↗
NASA NTRS1972

Solar and galactic cosmic ray exposure of Surveyor 3 as determined from cosmogenic radionuclide measurements

The proton-produced Na-22 content of samples of Surveyor 3 TV camera, surface sampler scoop, and other components was determined by nondestructive gamma ray spectrometry. The contributions of the nine most prominent solar flares to Na-22 production were calculated to be 18 dpm/kg. The observed activity in the Surveyor 3 samples was 62 + or - dpm/kg. This indicates a galactic proton contribution of about 44 dpm/kg, which adjusted for spallation of Al gives a value of 42 dpm/kg. This is compared to measurements of 88 dpm/kg in the Lost City meteorite which had an orbit extending to 2.35 AU, with a 4 pi bombardment as compared to the 2 pi bombardment of the samples on the lunar surface. The agreement between Na-22 production in Surveyor 3 and the Lost City meteorite offers evidence that the galactic cosmic ray flux is almost the same at 1 Au and at 2.35 AU.

Rancitelli, L. A.↗
NASA NTRS1971

Frequency domain stability criteria for distributed nonlinear sampled-data systems.

Popov-type sufficient conditions are presented for the absolute stability of a class of closed loop sampled-data systems. The closed loop system consists of a linear distributed element, a feedback controller (linear or nonlinear), a sampler, and possibly a zero-order hold circuit. The distributed element is assumed to be finite Hankel transformable, and such that its dynamics can be represented by a transfer function which is the ratio of the multiple (Laplace and finite Hankel) transforms of output and input. The input is assumed to be distributed. The stability criterion presented here parallels the criterion for distributed systems that are finite Fourier transformable. An example is given to illustrate the applications of the stability criterion.

Nagarajan, N.↗
NASA NTRS1971

Bearing strength of lunar soil.

Bearing load vs penetration curves have been measured on a 1.3 g sample of lunar soil from the scoop of the Surveyor 3 soil mechanics surface sampler, using a circular indentor 2 mm in diameter. Measurements were made in an Earth laboratory, in air. This sample provided a unique opportunity to evaluate earlier, remotely controlled, in-situ measurements of lunar surface bearing properties. Bearing capacity, measured at a penetration equal to the indentor diameter, varied from 0.02-0.04 N/sq cm at bulk densities of 1.15 g/cu cm to 30-100 N/sq cm at 1.9 g/cu cm. Deformation was by compression directly below the indentor at bulk densities below 1.61 g/cu cm, by outward displacement at bulk densities over 1.62 g/cu cm. Preliminary comparison of in-situ remote measurements with those on returned material indicates good agreement if the lunar regolith at Surveyor 3 has a bulk density of 1.6 g/cu cm at 2.5 cm depth.

Jaffe, L. D.↗
NASA NTRS1973

Design Modification of Electrophoretic Equipment

The improved design of a zone electrophoretic sampler is reported that can be used in mass screening for hemoglobin S, the cause of sickle cell anemia. Considered is a high voltage multicell cellulose acetate device that requires 5 to 6 minutes electrophoresis periods; cells may be activitated individually or simultaneously. A multisample hemoglobin applicator standardizes the amount of sample applied and transfers the homolysate to the electrical wires.

Reddick, J. M.↗
NASA NTRS1972

FCC in Viking articulated boom

The application requirements and manufacturing techniques for the flat conductor cable used in the Viking Lander Articulated Boom Unit are described. The Viking Boom is a 3-axis device utilized to position a soil sampler and provide digging forces. This application imposed severe restrictions on size, weight, materials, and choice of manufacturing processes. The final cable assembly design resulted in a combination of collated cable and flexible circuits assembled by resistance welding techniques.

Hawkins, E. S.↗