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All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Data collection procedures for the Software Engineering Laboratory (SEL) database

This document is a guidebook to collecting software engineering data on software development and maintenance efforts, as practiced in the Software Engineering Laboratory (SEL). It supersedes the document entitled Data Collection Procedures for the Rehosted SEL Database, number SEL-87-008 in the SEL series, which was published in October 1987. It presents procedures to be followed on software development and maintenance projects in the Flight Dynamics Division (FDD) of Goddard Space Flight Center (GSFC) for collecting data in support of SEL software engineering research activities. These procedures include detailed instructions for the completion and submission of SEL data collection forms.

Heller, Gerard↗
NASA NTRS1995

Application of the ionscan for the detection of methamphetamine and ephedrine in abondoned clandestine laboratories

Clandestine methamphetamine laboratories are prevalent in southern California. The most common encountered synthesis results in vapor release, and drug residue being left behind. The suspected manufacturing area can be vacuumed and/or methanol wiped and screened immediately at the lab site using the Ionscan. Positive results are confirmed by obtaining vacuum sweep samples with subsequent analysis at the DEA Laboratory. This procedure has been utilized successfully for identifying methamphetamine and ephedrine from clandestine laboratories that have been abandoned and/or remodeled.

Brown, Patricia A.↗
NASA NTRS1969

Apollo 11 impact on the occupational medicine program, NASA Manned Spacecraft Center

Requirements and development of standards for occupational medicine support of personnel in the Lunar Receiving Laboratory (LRL) are outlined. Considered are proper personnel performance and exclusion of people prone to develop a serious illness within the quarantine area. Occupational medicine report for the LRL consists of examination procedures covering laboratory work, periodic examinations, immunizations, health maintenance, preventive practices, medical standards, and waiver authority.

Wright, P. E.↗
NASA NTRS1988

Alignment verification procedures

In alignment verification procedures each laboratory is required to align its test machines and gripping fixtures to produce a nearly uniform tensile stress field on an un-notched sheet specimen. The blank specimens (50 mm w X 305 mm l X 2.3 mm th) supplied by the coordinators were strain gauged. Strain gauge readings were taken at all gauges (n = 1 through 10). The alignment verification procedures are as follows: (1) zero all strain gauges while specimen is in a free-supported condition; (2) put strain-gauged specimen in the test machine so that specimen front face (face 1) is in contact with reference jaw (standard position of specimen), tighten grips, and at zero load measure strains on all gauges. (epsilon sub nS0 is strain at gauge n, standard position, zero load); (3) with specimen in machine and at a tensile load of 10 kN measure strains (specimen in standard position). (Strain = epsilon sub nS10); (4) remove specimen from machine. Put specimen in machine so that specimen back face (face 2) is in contact with reference jaw (reverse position of specimen), tighten grips, and at zero load measure strains on all gauges. (Strain - epsilon sub nR0); and (5) with specimen in machine and at tensile load of 10 kN measure strains (specimen in reverse position). (epsilon sub nR10 is strain at gauge n, reverse position, 10 kN load).

Edwards, P. R.↗
NASA NTRS2014

Astromaterials Acquisition and Curation Office (KT) Overview

The Astromaterials Acquisition and Curation Office has the unique responsibility to curate NASA's extraterrestrial samples - from past and forthcoming missions - into the indefinite future. Currently, curation includes documentation, preservation, physical security, preparation, and distribution of samples from the Moon, asteroids, comets, the solar wind, and the planet Mars. Each of these sample sets has a unique history and comes from a unique environment. The curation laboratories and procedures developed over 40 years have proven both necessary and sufficient to serve the evolving needs of a worldwide research community. A new generation of sample return missions to destinations across the solar system is being planned and proposed. The curators are developing the tools and techniques to meet the challenges of these new samples. Extraterrestrial samples pose unique curation requirements. These samples were formed and exist under conditions strikingly different from those on the Earth's surface. Terrestrial contamination would destroy much of the scientific significance of extraterrestrial materials. To preserve the research value of these precious samples, contamination must be minimized, understood, and documented. In addition, the samples must be preserved - as far as possible - from physical and chemical alteration. The elaborate curation facilities at JSC were designed and constructed, and have been operated for many years, to keep sample contamination and alteration to a minimum. Currently, JSC curates seven collections of extraterrestrial samples: (a)) Lunar rocks and soils collected by the Apollo astronauts, (b) Meteorites collected on dedicated expeditions to Antarctica, (c) Cosmic dust collected by high-altitude NASA aircraft,t (d) Solar wind atoms collected by the Genesis spacecraft, (e) Comet particles collected by the Stardust spacecraft, (f) Interstellar dust particles collected by the Stardust spacecraft, and (g) Asteroid soil particles collected by the Japan Aerospace Exploration Agency (JAXA) Hayabusa spacecraft Each of these sample sets has a unique history and comes from a unique environment. We have developed specialized laboratories and practices over many years to preserve and protect the samples, not only for current research but for studies that may be carried out in the indefinite future.

Allen, Carlton↗
NASA NTRS1975

A sounding rocket spectroheliometer for photometric studies at extreme ultraviolet wavelengths

Construction and mode of operation are described for a sounding rocket spectroheliometer used to establish the sensitivity of the EUV spectroheliometer on the Skylab Apollo Telescope Mount (ATM). The sounding rocket instrument was calibrated immediately before and after two flights and the calibration was transferred when the rocket and ATM instruments simultaneously measured the average intensity emitted by a quiet area of the solar disk. Descriptions are presented for the payload assembly and flight sequence, the optical system (telescope, spectrometer, and pointing reference camera), the vacuum pumping system, and the instrument electronics. Results obtained from the two flights in August and December 1973 are discussed, which included unambiguous determinations of the absolute intensity emitted by a region of the quiet solar disk over the wavelength range from 1350 to 300 A on two separate occasions and the establishment of photometric accuracy to that of laboratory calibration procedures.

Timothy, J. G.↗
NASA NTRS1980

Buckling and postbuckling research on flat and curved composite panels

Progress in the development of verified design technology for generic advanced-composite structural components loaded in compression is reported. Generic structural configurations material systems and load ranges of interest for a given application were investigated using structural procedures, structural analysis procedures, and laboratory testing of structural specimens. Both flat and curved composite compression panels that are designed either to be buckling resistant or to have postbuckling strength depending on the expected application of the panels were considered.

Starnes, J. H., Jr.↗
NASA NTRS1980

P78-2 engineering overview

Data from the P78-2 spacecraft are being used in verifying and validating analytical tools being developed for the design of spacecraft, such as NASCAP, for updating Military Standard 1541, for investigation of materials contamination, and for a study of the physics of charging. The analysis of this data has already resulted in changes in laboratory testing procedures, in a better understanding of some properties of materials exposed to the space environment, and in some insight into the EMI caused by discharges on spacecraft in a plasma environment. Some examples of early results from the engineering experiments are presented.

Vampola, A. L.↗
NASA NTRS1985

Prediction of stable crack growth and instability using the V sub R-curve method

A methodology is presented for predicting stable crack growth and instability of cracked structural components from results of laboratory tests on metallic materials under plane-stress conditions. The methodology is based on the displacement V sub R at the tip of a stably tearing crack. Basically, the V sub R-curve method is a resistance curve approach, such as K sub R and J sub R, except that the 'crack drive' is written in terms of crack-tip displacement instead of K or J. The relationship between crack-tip-opening displacement, crack length, specimen type, and tensile properties is derived from the Dugdale model for the cracked structure of interest. This report describes the laboratory test procedure and calculations used to obtain the V sub R resistance curve from fracture tests of compact or of middle-crack tension (formally center-crack) specimens. The analysis procedure used to predict stable crack growth and instability of any through-the-thickness crack configuration made of the same material and thickness, and tested under the same environmental conditions, is presented. The various limitations of the present V sub R curve method are given. Four example calculations and predictions are shown.

Newman, J. C., Jr.↗
NASA NTRS1993

Comment on 'Summary and implications of reported amino acid concentrations in the Murchison meteorite' by E. L. Shock and M. D. Schulte

A criticism of the claim by Shock and Schulte (1990) that there is a correlation between the amino acid abundances (relative to glycine) in the Murchison meteorite and their aqueous solubilities is presented. Their suggestion that 'the same factors which control the aqueous solubility of many amino acids also control their relative abundances in the Murchison meteorite is argued to be incorrect. It is proposed that even though the water/meteorite ratio would have been less during meteorite aqueous alteration than that in the 100-C laboratory extraction procedure, amino acids are simply too soluble. The distribution of other meteorite organic components such as PAHs may have been affected by alteration because they are only slightly soluble in water and can be easily separated by geochromatographic processes. In their reply Shock and Schulte contend that the critics argue against a point not made in their paper and that their argument was supported with several unsubstantiated assertions, including an unfounded claim that the temperature dependence of amino acid solubilities are 'not greatly different', a misrepresentation of isopiestic studies on concentration solutions as equilibrium solubility measurements.

Miller, Stanley L.↗
NASA NTRS1939

Aircraft rate-of-climb indicators

The theory of the rate-of-climb indicator is developed in a form adapted for application to the instrument in its present-day form. Compensations for altitude, temperature, and rate of change of temperature are discussed from the designer's standpoint on the basis of this theory. Certain dynamic effects, including instrument lag, and the use of the rate-of-climb indicator as a statoscope are also considered. Modern instruments are described. A laboratory test procedure is outlined and test results are given.

Johnson, Daniel P↗
NASA NTRS1993

Identification of cometary and asteroidal particles in stratospheric IDP collections

He release temperature curves were determined for a specially processed set of 5 microns to 15 microns stratospheric IDP's whose masses, densities, and compositions were accurately measured. The He release temperature in combination with atmospheric entry calculations yields a most probable entry velocity for each particle and association with either an asteroidal (low velocity) or cometary (high velocity) origin. It was found that over half of the 5-15 microns IDP's have entry velocities consistent with asteroidal origin and that at least 20 percent have cometary origins. A few of the asteroidal particles are porous aggregates and it appears that there may be close material similarities among some primitive asteroids and comets. In the processing of individual 5 microns IDP's and determination of entry velocities, a few dozen microtome slices that can be used for a variety of detailed TEM, IR, and ion probe studies were preserved. These procedures provide laboratory samples that can be generically associated with asteroids and comets and are in a sense a limited sample return mission from these primitive bodies.

Brownlee, D. E.↗
NASA NTRS2001

Improved Spacecraft Materials for Radiation Protection

Methods by which radiation shielding is optimized need to be developed and materials of improved shielding characteristics identified and validated. The galactic cosmic rays (GCR) are very penetrating and the energy absorbed by the astronaut behind the shield is nearly independent of shield composition and even the shield thickness. However, the mix of particles in the transmitted beam changes rapidly with shield material composition and thickness. This results in part from the breakup of the high-energy heavy ions of the GCR which make contributions to biological effects out of proportion to their deposited energy. So the mixture of particles in the radiation field changes with shielding and the control of risk contributions from dominant particle types is critical to reducing the hazard to the astronaut. The risk of biological injury for a given particle type depends on the type of biological effect and is specific to cell or tissue type. Thus, one is faced with choosing materials which may protect a given tissue against a given effect but leave unchanged or even increase the risk of other effects in the same tissue or increase the risks to other adjacent tissues of a different type in the same individual. The optimization of shield composition will then be tied to a specific tissue and risk to that tissue. Such peculiarities arise from the complicated mixture of particles, the nature of their biological response, and the details of their interaction with material constituents. Aside from the understanding of the biological response to specific components, one also needs an accurate understanding of the radiation emerging from the shield material. This latter subject has been a principal element of this project. In the past ten years our understanding of space radiation interactions with materials has changed radically, with a large impact on shield design. For example, the NCRP estimated that only 2 g/sq cm. of aluminum would be required to meet the annual 500 mSv limit for the exposure of the blood forming organs (this limit is strictly for LEO but can be used as a guideline for the Mars mission analysis). The current estimates require aluminum shield thicknesses above 50 g/sq cm., which is impractical. In such a heavily shielded vehicle, the neutrons produced throughout the vehicle also contribute significantly to the exposure and this demands greater care in describing the angular dependence of secondary particle production processes. As such the continued testing of databases and transport procedures in laboratory and spaceflight experiments has continued. This has been the focus of much of the last year's activity and has resulted in improved neutron prediction capability. These new methods have also improved our understanding of the surface environment of Mars. The Mars 2003 NRA HEDS related surface science requirements were driven by the need to validate predictions on the upward flux of neutrons produced in the Martian regolith and bedrock made by the codes developed under this project. The codes used in the surface environment definition are also being used to look at in situ resources for the development of construction material for Martian surface facilities. For example, synthesis of polyimides and polyethylene as binders of regolith for developing basic structural elements has been studied and targets built for accelerator beam testing of radiation shielding properties. Preliminary mechanical tests have also been promising. Improved spacecraft materials have been identified (using the criteria reported by this project at the last conference) as potentially important for future shielding materials. These are liquid hydrogen, hydrogenated nanofibers, liquid methane, LiH, Polyethylene, Polysulfone, and Polyetherimide (in order of decreasing shield performance). Some of the materials are multifunctional and are required for other onboard systems. We are currently preparing software for trade studies with these materials relative to the Mars Reference Mission as required in the project's final year.

Wilson, John W.↗
NASA NTRS2004

Low Earth Orbital Atomic Oxygen Interactions With Materials

Atomic oxygen is formed in the low Earth orbital environment (LEO) by photo dissociation of diatomic oxygen by short wavelength (< 243 nm) solar radiation which has sufficient energy to break the 5.12 eV O2 diatomic bond in an environment where the mean free path is sufficiently long (~ 108 meters) that the probability of reassociation or the formation of ozone (O3) is small. As a consequence, between the altitudes of 180 and 650 km, atomic oxygen is the most abundant species. Spacecraft impact the atomic oxygen resident in LEO with sufficient energy to break hydrocarbon polymer bonds, causing oxidation and thinning of the polymers due to loss of volatile oxidation products. Mitigation techniques, such as the development of materials with improved durability to atomic oxygen attack, as well as atomic oxygen protective coatings, have been employed with varying degrees of success to improve durability of polymers in the LEO environment. Atomic oxygen can also oxidize silicones and silicone contamination to produce non-volatile silica deposits. Such contaminants are present on most LEO missions and can be a threat to performance of optical surfaces. The LEO atomic oxygen environment, its interactions with materials, results of space testing, computational modeling, mitigation techniques, and ground laboratory simulation procedures and issues are presented.

Banks, Bruce A.↗