Download or read book Atomic Oxygen Interaction with Spacecraft Materials Relationship Between Orbital and Ground based Testing for Materials Certification written by Jon B. Cross and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Oxygen Interaction with Spacecraft Materials written by and published by . This book was released on 1991 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of atomic oxygen on boron nitride, silicon nitride, solar cell interconnects used on the Intelsat 6 satellite, organic polymers, and MoS2 and WS2 dry lubricant have been studied in low Earth orbit (LEO) flight experiments and in our ground-based simulation facility at Los Alamos National Laboratory. Both the in-flight and ground-based experiments employed in situ electrical resistance measurements to detect penetration of atomic oxygen through materials and ESCA analysis to measure chemical composition changes. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN overcoated on thin silver was observed. No permeation of atomic oxygen through Si3N4 was observed. Test results on the Intelsat 6 satellite interconnects used on its photovoltaic array indicate that more than 60--80% of the original thickness of silver should remain after completion of the proposed Space Shuttle rescue/reboost mission. Gas phase reaction products produced by the interaction of high kinetic energy atomic oxygen (AO) with Kapton were found to be H2, H2O, CO, and CO2 with NO being a possible secondary product. Hydrogen abstraction at high AO kinetic energy is postulated to be the key reaction controlling the erosion rate of Kapton. An Arrhenius-like expression having an activation barrier of 0.4 eV can be fit to the data, which suggests that the rate limiting step in the AO/Kapton reaction mechanism can be overcome by translational energy. Oxidation of MoS2 and WS2 dry lubricants in both ground-based and orbital exposures indicated the formation of MoO3 and WO3 respectively. A protective oxide layer is formed (almost equal to)30 monolayers thick which has a high initial friction coefficient until the layer is worn off.
Download or read book Low Earth Orbital Atomic Oxygen Interactions with Spacecraft Materials written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic oxygen, formed in Earth s thermosphere, interacts readily with many materials on spacecraft flying in low Earth orbit (LEO). All hydrocarbon based polymers and graphite are easily oxidized upon the impact of approx.4.5 eV atomic oxygen as the spacecraft ram into the residual atmosphere. The resulting interactions can change the morphology and reduce the thickness of these materials. Directed atomic oxygen erosion will result in the development of textured surfaces on all materials with volatile oxidation products. Examples from space flight samples are provided. As a result of the erosive properties of atomic oxygen on polymers and composites, protective coatings have been developed and are used to increase the functional life of polymer films and composites that are exposed to the LEO environment. The atomic oxygen erosion yields for actual and predicted LEO exposure of numerous materials are presented. Results of in-space exposure of vacuum deposited aluminum protective coatings on polyimide Kapton indicate high rates of degradation are associated with aluminum coatings on both surfaces of the Kapton. Computational modeling predictions indicate that less trapping of the atomic oxygen occurs, with less resulting damage, if only the space-exposed surface is coated with vapor deposited aluminum rather than having both surfaces coated. Banks, Bruce A. and deGroh, Kim K. and Miller, Sharon K. Glenn Research Center NASA/TM-2004-213400, E-14905
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1991 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1993 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1986 with total page 1362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Oxygen Effects on Spacecraft Materials written by and published by . This book was released on 2003 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Protection of Materials and Structures From the Space Environment written by Jacob Kleiman and published by Springer Science & Business Media. This book was released on 2012-09-22 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goals of the 10th International Space Conference on “Protection of Materials and Structures from Space Environment” ICPMSE-10J, since its inception in 1992, have been to facilitate exchanges between members of the various engineering and science disciplines involved in the development of space materials, including aspects of LEO, GEO and Deep Space environments, ground-based qualification, and in-flight experiments and lessons learned from operational vehicles that are closely interrelated to disciplines of the atmospheric sciences, solar-terrestrial interactions and space life sciences. The knowledge of environmental conditions on and around the Moon, Mars, Venus and the low Earth orbit as well as other possible candidates for landing such as asteroids have become an important issue, and protecting both hardware and human life from the effects of space environments has taken on a new meaning in light of the increased interest in space travel and colonization of other planets. And while many material experiments have been carried out on the ground and in open space in the last 50 years (LDEF, MEEP, SARE, MISSE, AOP, DSPSE, ESEM, EURECA, HST, MDIM, MIS, MPID, MPAC and SEED), many questions regarding the environmental impact of space on materials remain either poorly understood or unanswered. The coming generations of scientists will have to continue this work and tackle new challenges, continuing to build the level of confidence humans will need to continue the colonization of space. It is hoped that the proceedings of the ICPMSE-10J presented in this book will constitute a small contribution to doing so.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 1470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Space Structures and Systems in the Space Station Era A Bibliography with Indexes supplement 05 written by and published by . This book was released on 1993 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Consequences of Atomic Oxygen Interaction With Silicone and Silicone Contamination on Surfaces in Low Earth Orbit written by and published by . This book was released on 1999 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1963 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of Ground Laboratory to In Space Effective Atomic Oxygen Fluence for DC 93 500 Silicone written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to calibrate the ground-to-space effective atomic oxygen fluence for DC 93-500 silicone in a thermal energy electron cyclotron resonance (ECR) oxygen plasma facility. Silicones, commonly used spacecraft materials, do not chemically erode with atomic oxygen attack like other organic materials but form an oxidized hardened silicate surface layer. Therefore, the effective atomic oxygen fluence in a ground test facility should not be determined based on mass loss measurements, as they are with organic polymers. A technique has been developed at the Glenn Research Center to determine the equivalent amount of atomic oxygen exposure in an ECR ground test facility to produce the same degree of atomic oxygen damage as in space. The approach used was to compare changes in the surface hardness of ground test (ECR) exposed DC 93-500 silicone with DC 93-500 exposed to low Earth orbit (LEO) atomic oxygen as part of a shuttle flight experiment. The ground to in-space effective atomic oxygen fluence correlation was determined based on the fluence in the ECR source that produced the same hardness for the fluence in-space. Nanomechanical hardness versus contact depth measurements were obtained for five ECR exposed DC 93-500 samples (ECR exposed for 18 to 40 hrs, corresponding to Kapton effective fluences of 4.2 x 10(exp 20) to 9.4 x 10(exp 20) atoms/sq cm, respectively) and for space exposed DC 93-500 from the Evaluation of Oxygen Interactions with Materials III (EOIM III) shuttle flight experiment, exposed to LEO atomic oxygen for 2.3 x 10(exp 20) atoms/sq cm. Pristine controls were also evaluated. A ground-to-space correlation value was determined based on correlation values for four contact depths (150, 200, 250, and 300 nm), which represent the near surface depth data. The results indicate that the Kapton effective atomic oxygen fluence in the ECR facility needs to be 2.64 times higher than in LEO to replicate equivalent exposure damage in the g
Download or read book Chemical Dynamics in Extreme Environments written by Rainer A. Dressler and published by World Scientific. This book was released on 2001 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: As computing power increases, a growing number of macroscopic phenomena are modeled at the molecular level. Consequently, new requirements are generated for the understanding of molecular dynamics in exotic conditions. This book illustrates the importance of detailed chemical dynamics and the role it plays in the phenomenology of a number of extreme environments. Each chapter addresses one or more extreme environments, outlines the associated chemical mechanisms of relevance, and then covers the leading edge science that elucidates the chemical coupling. The chapters exhibit a balance between theory and experiment, gas phase, solid state, and surface dynamics, and geophysical and technical environments.
Download or read book Oxygen Atom Reaction with Shuttle Materials at Orbital Altitudes written by and published by . This book was released on 1982 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Oxygen Protection of Materials in Low Earth Orbit written by and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
