International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / A real-time telemetry simulator of the IUS spacecraft has recently entered operation to train Flight Control Teams for the 1aunch of the AXAF telescope from the Shuttle. The simulator has proven to be a successful higher fidelity implementation of its predecessor, while affirming the rapid development methodology used in its design. Although composed of COTS hardware and software, the system simulates the full breadth of the mission: Launch, Pre-Deployment-Checkout, Burn Sequence, and AXAF/IUS separation. Realism is increased through patching the system into the operations facility to simulate IUS telemetry, Shuttle telemetry, and the Tracking Station link (commands and status message).

The objective of this diploma thesis is to perform a conceptual lay-out of a small launcher. Re- quirements have been defined in order to realize this first preliminary study and design of a small launcher. In that frame, a MATLAB code has been written in order to simulate the rocket tra- jectories. An optimization program on launcher staging has been written as well. To validate this code, the VEGA and Ariane 5 launchers have been used. Then from studies on existing launchers, simulations have been performed in order to find an optimum small launcher and later on to design more precisely the small launcher. As a requirement an upper stage has been newly designed for the purpose of the study. At the end, two small launchers have been considered: a three-stage launcher using the Zefiro 23 as a first stage, the Zefiro 9 as a second stage, and an upper stage using a 3kN thrust engine; a two-stage launcher using the Zenit booster engine in the first stage, and an upper stage using a 22kN thrust engine.

<div><div><div><p>The exponential growth of space debris poses a significant threat to humankind’s activities in orbit. It is thus worthwhile to investigate debris-generating events and uncover their causes, consequently informing debris-mitigation guidelines and safer spacecraft design. This work sets out to examine three fragmentation events pertaining to Centaur upper stages which have yet to be fully understood. Critical breakup characteristics such as breakup epoch, fragment velocities, and angular distributions for the Centaur events, as well as select historic fragmentation events are presented. Subsequently, hypotheses regarding the causes of the events are postulated. The Centaur fragmentations stray from breakup patterns exhibited by ’typical’ upper stage fragmentations such as those of the historic explosive Delta upper stage events. Only one of the three events, 2018-079B, appears to have fragmented due to the combustion of leftover propellant. 2009-047B, on the other hand, likely endured a structural failure – inferred from clustered fragments and low fragment spreading speeds. A torus-shaped fragment distribution is observed for the 2014-055B event, suggesting a collision with a small piece of debris may have taken place.</p></div></div></div>

På grund av mångfalden i dagens svenska skolor kan inte alltid traditionellt arbetssätt i matematikundervisning främja elever att utveckla sina förmågor såsom analys- och resonemangsförmåga. Läroboksstyrda lektioner ger inte elever möjligheter att komma till tals, lyssna på andras resonemang, tänka kritiskt och analysera andras tankesätt. Därför som matematiklärare blir det intressant att undersöka hur lärarna på alla stadier (låg-, mellan- respektive högstadiet) använder sig av dialogisk undervisning och vilken form av dialogisk undervisning som dominerar i respektive stadie. Därför genomfördes en fallstudie av dialogisk undervisning inom ramen för detta självständiga arbete. Datainsamlinggenomfördes genom observation samt ljudinspelning, i en lågstadie-, i en mellanstadie- och i en högstadieklass, sammanlagt nio lektioner. För att kunna analysera data har Robin Alexanders välkända ramverk för dialogisk undervisning använts (presenterat bl.a. i artikeln Developing dialogic teaching, 2018). I ramverket kategoriseras undervisningen utifrån repertoarer och principer som belyser olika aspekter av dialoger i klassrummet. Fallstudien visade att lektioner präglade av dialog förekom mest på låg- och mellanstadiet och i mindre utsträckning på högstadiet. Lärarnas främsta teaching talk bestod av recitation (initiera-respons-feedback) men kompletterat med hur och varför i hög grad i låg- och mellanstadielektioner med syfte att föra samtalet vidare vilket i sin tur möjliggjorde för att eleverna att komma till tals för att förklara och motivera sitt tänkande till skillnad från på högstadielektionerna där elevernas främsta learning talk bestod av korta svar. / Due to the diversity in today's Swedish schools, traditional methods in mathematics teaching can’t always promote students to develop their abilities such as analytical and reasoning skills. Textbook-guided lessons don’t give students opportunities to speak, listen to others thoughts, think critically and analyze the thinking of others. Therefore, as a mathematics teacher, it will be interesting to investigate how teachers at all stages (primary, intermediate, and upper-secondary) use dialogic teaching and which form of dialogic teaching dominates in each stage. Therefore, a case study of dialogic teaching was conducted within the framework of this independent work. Data collection was carried out through observation and sound recording, in an elementary school, in an intermediate school and in a high school class, a total of nine lessons. In order to be able to analyze data, Robin Alexander's well-known framework for dialogic teaching has been used (presented in the article Developing dialogic teaching, 2018). The framework categorizes teaching on the basis of repertoires and principles that illuminate various aspects of dialogues in the classroom. The case study showed that lessons characterized by dialogue occurred mostly in primary and middle school and to a lesser extent in high school. The teachers' main teaching talk consisted of recitation (initiate-response-feedback) but supplemented with how and why to a large extent in the primary and intermediate stage with the aim of passing on the conversation, which in turn made it possible for the students to speak to explain and motivate their thinking unlike in high school where the students' main learning talk consisted of short answers.

A need to find better achievement has always been required in the space industrythrough time. Advanced technologies are provided to accomplish goals for humanityfor space explorer and space missions, to apprehend answers and widen knowledges. These are the goals of improvement, and in this thesis, is to strive and demandto understand and improve the mass of a space nozzle, utilized in an upperstage of space mission, with an expander cycle engine. The study is carried out by creating design of experiment using Latin HypercubeSampling (LHS) with a consideration to number of design and simulation expense.A surrogate model based optimization with Multidisciplinary Design Optimization(MDO) method for two different approaches, Analytical Target Cascading (ATC) and Multidisciplinary Feasible (MDF) are used for comparison and emend the conclusion. In the optimization, three different limitations are being investigated, designspace limit, industrial limit and industrial limit with tolerance. Optimized results have shown an incompatibility between two optimization approaches, ATC and MDF which are expected to be similar, but for the two limitations, design space limit and industrial limit appear to be less agreeable. The ATC formalist in this case dictates by the main objective, where the children/subproblems only focus to find a solution that satisfies the main objective and its constraint. For the MDF, the main objective function is described as a single function and solved subject to all the constraints. Furthermore, the problem is not divided into subproblems as in the ATC. Surrogate model based optimization, its solution influences by the accuracy ofthe model, and this is being investigated with another DoE. A DoE of the full factorial analysis is created and selected to study in a region near the optimal solution.In such region, the result has evidently shown to be quite accurate for almost allthe surrogate models, except for max temperature, damage and strain at the hottestregion, with the largest common impact on inner wall thickness of the space nozzle. Results of the new structure of the space nozzle have shown an improvement of mass by ≈ 50%, ≈ 15% and ≈ -4%, for the three different limitations, design spacelimit, industrial limit and industrial limit with tolerance, relative to a reference value,and ≈ 10%, ≈ 35% and ≈ 25% cheaper to manufacture accordingly to the defined producibility model.