International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper details the interaction of a small satellite with a space network and estimates the number of contacts and duration of contacts between the small, spin-stabilized satellite and a TDRS satellite. The simulations were performed using Satellite Tool Kit (STK) version 3.0, an orbital analysis software program. STK was configured for the four vehicles representing the spin-stabilized satellite and three TDRS satellites, TDRS East, West, and TDRS Zone of Exclusion. A set of simulations were run in which the spinstabilized satellite was given orbital elements corresponding to an orbital altitude between 600 km and 1200 km. The orbital inclination angle for the set of simulations was also varied from 20° through 100° along with the antenna cone angle of 10° through 40° to account for the effective beamwidths. In each of the simulations, the access to each TDRS satellite in the SN constellation was examined as a function of orbital altitude, orbital inclination angle, and antenna cone angle.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / With explosive growth in the satellite communication market. there is an increasing need for the satellite network service providers to support many satellites with a common Telemetry, Tracking, and Commanding (TT&C) assets. The open bus technology, and Commercial Off The Shelf (COTS) Hardware and Software components, provides an opportunity to build a common IF and baseband systems that will support many satellites with different frequencies and protocols. However, the high frequency front end components of the ground station such as antenna or HPA can not be common due to different gain and polarization requirements of the various communication bands and frequencies. The system architecture presented in this paper offers such system that is interoperable and reconfigurable in near real-time to support multiple frequency and multiple communication protocols.

Le contexte de recherche de cette thèse est le développement d'outils informatiques dans un cadre interculturel. La thèse prend comme cas d'étude le peuple nasa, aborigène de Colombie conservant d'importantes caractéristiques culturelles. La problématique de recherche est née à partir des différences culturelles entre ce peuple rural et la société productrice des dispositifs informatiques. Les processus d'adaptation culturelle se concentrent en général sur la traduction textuelle et sur des éléments faciles à étudier. Cependant, la culture est implicite dans une large gamme d'aspects de la conception et utilisation d'un système informatique. Par exemple, la métaphore du bureau est basée sur des éléments typiques d'un environnement de travail urbain. Toutefois, les dossiers, fichiers et autres composants de l'interface sont moins courants dans le contexte nasa. Cette thèse réalise deux contributions majeures. Premièrement, un modèle culturel qui aide à l'étude de caractéristiques socioculturelles importantes dans le développement d'outils informatiques (la langue, l'environnement et la technologie, l'organisation sociale, la structuration de l'espace, et les signes non-linguistiques). Deuxièmement, une méthode de description de conception intégrant les caractéristiques culturelles à des patrons de conception. Ceux-ci rendent possible la représentation de l'influence de la culture sur la production d'un outil. Ces contributions ont été appliquées dans le contexte nasa et deux outils ont été mis en oeuvre dans deux écoles en suivant une méthode de conception participative. Un catalogue initial de patrons décrit la résolution de différents problèmes de conception.

Approved for public release; distribution in unlimited. / The International Space Station (ISS) must be able to withstand the hypervelocity impacts of micrometeoroids and orbital debris that strike its many surfaces. In order to design and implement shielding which will prevent hull penetration or other operational losses, NASA must first model the orbital debris and micrometeoroid environment. Based upon this environment, special multi-stage shields called Whipple and Enhanced Stuffed Whipple Shields are developed and implemented to protect ISS surfaces. Ballistic limit curves that establish shield failure criteria are determined via ground testing. These curves are functions of material strength, shield spacing, projectile size, shape and density, as well as a number of other variables. The combination of debris model and ballistic limit equations allows NASA to model risk to ISS using a hydro-code called BUMPER. This thesis modifies and refines existing ballistic limit equations for U.S. Laboratory Module shields to account for the effects of projectile (debris/ micro-meteoroid) densities. Using these refined ballistic limit equations this thesis also examines alternative shielding materials and configurations to optimize shield design for minimum mass and maximum stopping potential, proposing alternate shield designs for future NASA ground testing. A final goal of this thesis is to provide the Department of Defense a background in satellite shield theory and design in order to improve protection against micrometeoroid and orbital debris impacts on future spacebased national systems. / Lieutenant, United States Navy

O grau de exigência da sociedade no atendimento das suas necessidades vem aumentando progressivamente, bem como a complexidade tecnológica dos bens e serviços oferecidos. Para se atender a essa acelerada evolução, o processo de inovação tecnológica precisa atingir um nível de eficiência e eficácia que articule todos os atores do processo de inovação em redes de cooperação, pois já não há mais lugar para o trabalho organizacional solitário. No novo cenário, há necessidade de parcerias para que novos produtos e processos atinjam a sua verdadeira utilidade, que é a melhoria da qualidade de vida da humanidade. Nesse contexto, o setor espacial tem um papel de destaque, seja por meio da monitoração climática ou até de equipamentos de medicina preventiva, desenvolvidos a partir de tecnologias espaciais. Assim, o Brasil tem utilizado o programa de parceria Uniespaço, sob coordenação da Agência Espacial Brasileira (AEB), para transferir tecnologias para o seu setor espacial. Com base na experiência internacional dos programas espaciais e do levantamento da literatura, este estudo parte do pressuposto de que a eficácia da transferência de tecnologia (TT) nos programas de parceria pode ser alcançada mediante a superação de barreiras existentes no processo, por intermédio de elementos facilitadores. Desta forma, a pesquisa teve por objetivo identificar os fatores críticos entre atores no processo de TT, a partir de estudos de 05 projetos de parceria do programa Uniespaço. As organizações geradoras da tecnologia foram três instituições de ensino superior e quatro institutos de Pesquisa & Desenvolvimento (P&D), tendo como usuários o Instituto Nacional de Pesquisas Espaciais (INPE) e o Instituto de Aeronática e Espaço (IAE). Além desse programa, foi estudado o programa de parceria inovativa (PPI) da NASA, identificando o arranjo organizacional e os fatores que fomentam a TT entre os atores do sistema setorial de inovação e produção espacial dos EUA. O presente trabalho teve como resultado principal a elaboração de dois modelos conceituais; o primeiro focando a TT entre gerador e usuário em termos dos fatores críticos obtidos na pesquisa, dentre eles o nível de maturidade tecnológica, adaptação da nova tecnologia versus a cultura tecnológica do usuário, e capacitações de absorção tecnológica e inovativa, e o segundo modelo como resultado da formação de parcerias e do impacto dos demais atores sociais envolvidos nos processos de TT. / The level of requirement of the society in order to satisfy its needs has been increasing progressively, as well as, the technology complexity of goods and services offered. In order to follow this evolution, the technology innovation process needs to achieve a certain level of efficiency and effectiveness, which is able to articulate all players of the innovation process in the network cooperation, in other words, there is no place for solitary organizational work. Partnerships are required to produce new products and processes to achieve its goals and promote a better quality of life. The space sector has an important role, such as the earth climate monitoring and preventive medicine equipments that were developed from technologies used for space applications. Therefore, similarly to other countries, Brazil has transferred technologies to its space sector, through partnership programs, though, sometimes with no success. The assumption of this study was the effectiveness of technology transfer in the partnership programs can be achieved by overcoming the barriers in the process through specific facilitators, and it was based on the international experience of space programs and literature review. The aim of this dissertation was to identify critical factors between players in the technology transference process on the brazilian space sector. The methodology used was based on case studies of five partnership projects and involved both three universities and four R&D institutes in the brazilian partnership program called Uniespaço, which is coordinated by the Brazilian Space Agency (AEB). The NASAs innovative partnership program was also studied, in order to know the organizational arrangement and the technology transfer facilitators between players in the US space sector system of innovation and production. The main results of this dissertation were two new conceptual models; the first was based on critical factors of TT between technology generators and users, such as, technology maturity level, adaptation of new technology versus users technological culture, and the ability of absorbing technology and innovation; the second model was the result of the dynamic of partnership formation and the impact of social players involved in the TT process.

In the spring of 1999 NASA will launch the scatterometer SeaWinds, beginning a 3 year mission to measure the ocean winds. SeaWinds is different from previous spaceborne scatterometers in that it employs a rotating pencil-beam antenna as opposed to fixed fan-beam antennas. The scanning beam provides greater coverage but causes the wind retrieval accuracy to vary across the swath. This thesis develops a filed-wise wind retrieval algorithm to improve the overall wind retrieval accuracy for use with SeaWinds data. In order to test the field-wise wind retrieval algorithm, methods for simulating wind fields are developed. A realistic approach interpolates the NASA Scatterometer (NSCAT) estimates to fill a SeaWinds swath using optimal interpolation along with linear wind filed models. The two stages of the field-wise wind retrieval algorithm are filed-wise estimation and field-wise ambiguity selection. Field-wise estimation is implemented using a 22 parameter Karhunen-Loeve (KL) wind field model in conjunction with a maximum likelihood objective function. An augmented multi-start global optimization is developed which uses information from the point-wise estimates to aid in a global search of the objective function. The local minima in the objective function are located using the augmented multi-start search techniques and are stored as field-wise ambiguities. The ambiguity selection algorithm uses a field-wise median filter to select the field-wise ambiguity closest to the true wind in each region. Point-wise nudging is used to further improve the filed-wise estimate using information from the point-wise estimates. Combined, these two techniques select a good estimate of the wind 95% of the time. The overall performance of the field-wise wind retrieval algorithm is compared with the performance of the current point-wise techniques. Field-wise estimation techniques are shown to be potentially better than point-wise techniques. The field-wise estimates are also shown to be very useful tools in point-wise ambiguity selection since 95.8%-96.6% of the point-wise estimates closest to the field-wise estimates are the correct aliases.

In order to fully understand the role methane (CH₄) plays in the microwave emission spectra of the deep atmospheres of the outer planets, over 280 laboratory measurements of the opacity of ammonia in a methane environment have been made in the 5-20 cm wavelength range. All opacity measurements were made with either 100 or 200 mbars of ammonia and with 1 to 3 bars of added methane in the 330-450K temperature range. A formalism for the absorptivity of ammonia broadened by methane has now been developed and had been applied to the Hanley et al. (Icarus, v. 202, 2009) model for the opacity of ammonia. Due to methane's relatively low abundance at Jupiter (~0.2% by volume), its effect on the microwave spectrum which will be observed by the Juno MWR (Microwave Radiometer) will be minimal. However, these experimental results will significantly improve the understanding of the microwave emission spectrum of Uranus and Neptune where methane plays a more dominant role.

Aufgrund des Mißerfolges der Mars Observer Mission 1992 und allgemeiner sinkender Raumfahrtetats, entwickelte NASA 1995 die „Faster Better Cheaper“ (FBC) Philosophie. Diese sah vor, daß planetare Missionen innerhalb eines kurzen Zeitraumes und mit begrenzten Budgets geplant, gebaut, getestet und gestartet werden sollten. Dabei sollten neue Technologien und neue Betriebsmethoden zum Einsatz kommen. Mögliche Fehlschläge durch unerprobte Instrumente oder Prozesse wurden dabei nicht ausgeschlossen. Der Mißerfolg der Mars-Missionen im Jahr 1999 und weiterer Projekte zwangen jedoch zu einem Umdenken der „Faster Better Cheaper“ Philosophie. Eine Vielzahl von Abhandlungen und Untersuchungen wurden daraufhin veröffentlicht, die Fehler der FBC Philosophie aufzeigten, ohne dabei jedoch auf mögliche Verbesserungen einzugehen. Das Ziel dieser Arbeit besteht in der Ermittlung effektiver Maßnahmen, so daß Ressourcen während des Lebenszyklus eines Projektes optimal eingesetzt werden können. Aus der Analyse der fehlgeschlagenen Missionen und einer Erläuterung der Funktionen verschiedener planetarer Missionskonzepte, werden mögliche Maßnahmen zur Verringerung der Kosten ermittelt. Die Effektivität dieser Maßnahmen wird anhand eines Bewertungskataloges im Rahmen einer Simulation zu verschiedenen Zeitpunkten einer Mission bestimmt. Es wird dabei eine Handlungshilfe erstellt, mit der ein Projektmanager die Verteilung von Ressourcen optimieren kann. Die Systemtechnik bietet hierzu eine Vielzahl von Analyse- und Simulationsmethoden, mit der die hier gemachten Angaben bewertet und überprüft werden können. / Due to the failure of the Mars Observer Mission in 1992 and decreasing budgets, NASA developed a new philosophy for the development, design and operations called „Faster Better Cheaper“ (FBC). New technologies and new management methods were deployed to reduce lift cycle costs. Possible mission failures were expected. After the losses of the Mars Missions in 1999 and other missions, NASA was forced to rethink its FBC approach. Numerous papers have been published in the meantime which identified the mistakes of the missions and of FBC, but none have identified potential improvements. The objective of this paper is the development of potential measurements for the design of the operations of unmanned space missions that should be applied during its life cycles. A new tool in form of an EXCEL spreadsheet will be developed based on historical missions, which can be used a program manager who can allocate resources in optimal way. Systems Engineering Techniques will be used in various ways to identify problems and to measure potential improvements.

The aerospace industry has been concerned with propeller noise levels for years. This interest is two-fold: government regulation and comfort in cabin. This report attempts to create a simulation mechanism needed to evaluate the far-field noise generation levels. However, in order to do that, the tandem cylinder case was evaluated first as a validation step before the SR-7A propeller case was performed. Both cases use STAR-CCM+, a commercial software, to perform the simulations.

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2626" Daniel Bryan Gazda. 12/19/2004. Report is also available in paper and microfiche from NTIS.