Download or read book LDEF 69 Months in Space First Post Retrieval Symposium Part 1 written by and published by . This book was released on 1992 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: LDEF was carried into orbit in April 1984 by the Space Shuttle Challenger. The 11-ton satellite contained 57 experiments to assess the effects of the space environment, i.e., ionizing radiation, meteoroids, cosmic dust, and high altitude atomic oxygen on materials and mechanical, electronic, optical, and living systems. In January 1990, after 69 months in low Earth orbit, LDEF was retrieved by the Space Shuttle Columbia and returned to Earth. The retrieval occurred 57 months after it was originally planned, due in part to the Challenger tragedy. The 69 months in space provided experimenters the unique opportunity to sample and measure the space environment over a longer time period than originally planned. The 57 LDEF experiments were returned to the Principal Investigators and their science teams for analyses and interpretation. In June 1991, over 400 LDEF researchers and data users met in Kissimmee, Florida for the First LDEF Post-Retrieval Symposium. The papers presented contained important new information about space environments and their impact on materials, systems, and biology.
Download or read book LDEF 69 Months in Space Part 1 Second Post Retrieval Symposium written by and published by . This book was released on 1993 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Orbiting Eyes written by Don Nardo and published by Capstone. This book was released on 2009 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: When you look up at the night sky, do you ever wonder why some stars seem to move? These moving lights are not stars. They are artificial satellites, machines put into space to help us communicate or gather information here on Earth. From the launch of the first artificial satellite in 1957 to the space telescopes making headlines today, these orbiting eyes have helped us study the heavens, survey the earth, stay in touch, and protect our homelands. Headline Science uses news stories and everyday applications to explain the science behind artificial satellites.
Download or read book LDEF A Bibliography with Abstracts written by and published by . This book was released on 1992 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book LDEF 69 Months in Space Third Post Retrieval Symposium Part 1 written by and published by . This book was released on 1995 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book LDEF 69 Months in Space First Post Retrieval Symposium Part 3 written by and published by . This book was released on 1991 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Orbital Debris written by National Research Council and published by National Academies Press. This book was released on 1995-07-07 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the beginning of space flight, the collision hazard in Earth orbit has increased as the number of artificial objects orbiting the Earth has grown. Spacecraft performing communications, navigation, scientific, and other missions now share Earth orbit with spent rocket bodies, nonfunctional spacecraft, fragments from spacecraft breakups, and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft. Potential methods to protect spacecraft are explored. The report also takes a close look at the projected future growth in the debris population and evaluates approaches to reducing that growth. Orbital Debris offers clear recommendations for targeted research on the debris population, for methods to improve the protection of spacecraft, on methods to reduce the creation of debris in the future, and much more.
Download or read book LDEF 69 Months in Space written by Arlene S. Levine and published by . This book was released on 1991 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selfies from Space written by Tamra B. Orr and published by Capstone Press. This book was released on 2019 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Describes how scientists are using satellites to tackle some of our world's most challenging problems"--
Download or read book Composite Materials in Space Results from the LDEF Satellite written by Roderick Clarence Tennyson and published by . This book was released on 1991 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geometry and Mass Model of Ionizing Radiation Experiments on the Ldef Satellite written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive measurements related to ionizing radiation environments and effects were made on the LDEF satellite during its mission lifetime of almost 6 years. These data, together with the opportunity they provide for evaluating predictive models and analysis methods, should allow more accurate assessments of the space radiation environment and related effects for future missions in low Earth orbit. The LDEF radiation dosimetry data is influenced to varying degrees by material shielding effects due to the dosimeter itself, nearby components and experiments, and the spacecraft structure. A geometry and mass model is generated of LDEF, incorporating sufficient detail that it can be applied in determining the influence of material shielding on ionizing radiation measurements and predictions. This model can be used as an aid in data interpretation by unfolding shielding effects from the LDEF radiation dosimeter responses. Use of the LDEF geometry/mass model, in conjunction with predictions and comparisons with LDEF dosimetry data currently underway, will also allow more definitive evaluations of current radiation models for future mission applications. Colborn, B. L. and Armstrong, T. W. Unspecified Center NAS8-39121...
Download or read book Partial Analysis of Ldef Experiment A 0114 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the contract period, work concentrated on four main components. Data from the UAH silver pin hole camera was analyzed for determination of the mean Long Duration Exposure Facility (LDEF) satellite attitude and stability in orbit, to include pitch and yaw. Chemical testing performed on the AO-114 hot plate determined the form and locus of absorption of cosmogenic beryllium-7. Reaction rates of atomic oxygen with Kapton and other polymeric solids integrated over the whole LDEF orbital lifetime were analyzed. These rates were compared with the JSC estimated values for Space Station exposures. Metal and polymer films exposed on A0114 (C-9 and C-3 plates) were also analyzed. Gregory, John C. Unspecified Center NAS8-36645...
Download or read book Analysis Review and Documentation of the Activation Data from Ldef Material written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Samples removed from Long Duration Exposure Facility (LDEF-1) are being studied at various laboratories to determine the specific activity(pCi/kg) produced in orbit by exposure to protons and neutrons in near-Earth orbit. These activities are being corrected for efficiency, self-attenuation, and background. The activities and associated gamma-ray spectra are being collected, analyzed, documented and reviewed by faculty and graduate students at Eastern Kentucky University. The currently available activation results have been tabulated and reviewed in this report. Approximately 500 spectra have been accumulated for future archival and analysis. The effect of the changing satellite orbit on the activation is reported herein and was calculated using more recent estimates of the flux of Van Allen belt protons. Laird, C. E. Unspecified Center...
Download or read book An Interim Overview of Ldef Materials Findings written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. In general, the LDEF data is remarkably consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8 years; other 'space qualified' materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom. Stein, Brad A. Langley Research Center...
Download or read book Scoping Estimates of the Ldef Satellite Induced Radioactivity written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-16 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Long Duration Exposure Facility (LDEF) satellite was recovered after almost six years in space. It was well-instrumented with ionizing radiation dosimeters, including thermoluminescent dosimeters, plastic nuclear track detectors, and a variety of metal foil samples for measuring nuclear activation products. The extensive LDEF radiation measurements provide the type of radiation environments and effects data needed to evaluate and help resolve uncertainties in present radiation models and calculational methods. A calculational program was established to aid in LDEF data interpretation and to utilize LDEF data for assessing the accuracy of current models. A summary of the calculational approach is presented. The purpose of the reported calculations is to obtain a general indication of: (1) the importance of different space radiation sources (trapped, galactic, and albedo protons, and albedo neutrons); (2) the importance of secondary particles; and (3) the spatial dependence of the radiation environments and effects expected within the spacecraft. The calculational method uses the High Energy Transport Code (HETC) to estimate the importance of different sources and secondary particles in terms of fluence, absorbed dose in tissue and silicon, and induced radioactivity as a function of depth in aluminum. Armstrong, Tony W. and Colborn, B. L. Unspecified Center...
Download or read book The Space Environment written by Alan C. Tribble and published by Princeton University Press. This book was released on 2020-05-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The breakup of the Space Shuttle Columbia as it reentered Earth's atmosphere on February 1, 2003, reminded the public--and NASA--of the grave risks posed to spacecraft by everything from insulating foam to space debris. Here, Alan Tribble presents a singular, up-to-date account of a wide range of less conspicuous but no less consequential environmental effects that can damage or cause poor performance of orbiting spacecraft. Conveying a wealth of insight into the nature of the space environment and how spacecraft interact with it, he covers design modifications aimed at eliminating or reducing such environmental effects as solar absorptance increases caused by self-contamination, materials erosion by atomic oxygen, electrical discharges due to spacecraft charging, degradation of electrical circuits by radiation, and bombardment by micrometeorites. This book is unique in that it bridges the gap between studies of the space environment as performed by space physicists and spacecraft design engineering as practiced by aerospace engineers.
