577 research outputs found
Development of low cost double probe plasma measurement system for a lean satellite HORYU-IV
No full textA lean satellite is equivalent to a small/micro/nano/pico satellite that utilizes untraditional risk-taking development approaches to achieve low-cost and fast-delivery. Lean satellites have demonstrated great ability to be used for the study of space plasma and Earth’s ionosphere which has helped in the prediction of many astrophysical phenomena and forecasting of geophysical changes on ground. Several methods have been employed in the measurement of space plasma parameters over the years using the Langmuir Probe. These methods employed different techniques using single probes or double probes. Single probe requires a well-defined reference which is difficult in small spacecraft. Moreover, high current flow in the saturation mode may destroy the probe and on-board circuitry. A low cost double Langmuir probe made of gold with its measurement circuit has been designed and tested inside RF generated Argon plasma in the pressure of 1.4×10-2 Pa that confirms the electron density from 1010 to 1012 m-3. Important design considerations such as operability of the designed system in low earth orbit grade plasma, mitigation of probe contamination and sputtering of the electrode surface were analysed in the paper to ensure that the developed system can provide high fidelity plasma measurement data throughout the life span of HORYU-IV (Arc Event Generator and Investigator Satellite) which is a 13 kg, 40 cm cubic lean satellite under development at the Kyushu Institute of Technology
Mejora de la Fuerza de Arrastre por Colisión de Iones en el Panel Conductivo de Alta Tensión en un Cubesat
No full textHoy en día, hay una gran explosión para lanzar los nanosatélites a la órbita terrestre baja (LEO) ya que pueden ser fabricados fácilmente por universidades o empresas. No es asi requerido tanto dinero para probar y hacer experimentos en el espacio con fines científicos que muchas universidades están muy interesadas en construir nanosatélites para probar y probar nuevos científicos equipo. Sin embargo, esta relativa accesibilidad abierta para poner en órbita cualquier nanosatélites tenía aumento de los desechos espaciales que ahora se considera un gran problema para futuras misiones al espacio.
Las agencias de la Organización y del Espacio intentaron mitigar este efecto irreversible haciendo algunos requisitos y especificaciones para que los nanosatélites los conviertan en desorbitado más rápido y disminuyan la basura en el espacio.
El propósito de esta tesis es proporcionar otra fuerza de arrastre, que en realidad está actuando en todos satélites, para hacerlos decaer más rápido en la Tierra. Los satélites en el espacio están en plasma medio ambiente, que son básicamente iones y electrones que se mueven aleatoriamente en el espacio. Los la interacción entre satélite y plasma se basa en iones, que son mucho más pesados que electrón. Cuando los iones colisionan en la superficie del satélite, producen cierta fuerza debido a la cambio de impulso, sin embargo, este valor de intercambio de momento es demasiado pequeño y es considérelo como una fuerza despreciable para calcular el tiempo de deorbitación. Esta tesis se centra principalmente en polarizando una superficie conductora en la nave espacial, mejorará la fuerza del plasma y hará satélites decaer más rápido en la Tierra.Tesi
Comparison of Thermal Design of Horyu-Series and Results of Thermal Vacuum Testing
No full textJapanViet NamKyushu Institute of TechnologyVNSC107ICES107: Thermal Design of Microsatellites, Nanosatellites, and PicosatellitesVienna, AustriaHirokazu Masui, Kyushu Institute of Technology, JapanThe 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.Mengu Cho, Kyushu Institute of Technology, JapanTakashi Yamasaki, Kyushu Institute of Technology, JapanThin Tang Long, Vietnam National Space Center (VNSC), VietnamThis paper describes the thermal design and testing of Horyu-4 to be launched in 2016. Kyushu Institute of Technology (KIT) has been developing nano-satellite since 2006. 2 nano-satellites (Horyu-2) and Shinen-2)) have been launched so far. In 2016, Horyu-4 will be launched by JAXA H2A rocket. Horyu-4 satellite project was started from 2013 and a basic design of Horyu-4 is based on that of Horyu-2 launched in 2012. Horyu-4 is 30cm-cube satellite and its weight is 12 kg. A main mission of Horyu-4 is observation of discharge phenomena on solar cell in space. Main changes from Horyu-2 are (1) increasing in weight with increasing mounted mission components, (2) changing of orbit inclination from 98.1˚ to 51.6˚, and (3) changing of orbit altitude from 680 km to 575 km. The different point in a thermal design of Horyu-2 and 4 from a conventional nano and micro-satellite is a wide temperature fluctuation due to low density. Horyu-4 adopts a passive thermal control. Surface properties of external panels and insulation between internal circuit boards and structure frames were adjusted to ensure acceptable temperature ranges including margin for internal circuit boards. To verify the thermal design and operation of bas system and components, thermal vacuum tests were conducted in each development phase.
This paper will explain the detail of Horyu-4’s thermal design comparing with Horyu-2’s design and on-orbit data. In addition, results and testing method for thermal vacuum testing will be reported. Finally, flight prediction data and on-orbit data will be compared
The Alliance between Mengu-Timur and Abaga: The Problem of Sources Interpretation and Translation of Persian and Turkic Terms in Arabic Texts (on the example of “Collection of Materials Relating to the Golden Horde History. Volume I. Excerpts from the Arabic Writings” composed by V.G. Tiesenhausen) »
No full textThe article deals with the problem of translation of Persian and Turkic lexical units in Arabic texts written between the 13th and 16th centuries. Author examines as an example an excerpt from the work of Ibn Khaldun (732/1332 – 808/1406) translated by V.G. Tiesenhausen. The author provides comments to the given translation and presents his own translation.
The author also presents original analysis of the source both about the relations between Golden Horde and Constantinople and on the battle of Homs in 680 AH between Mangu Timur, son of Hulagu, and the Mamluk sultan al-Mansur. The author tries to prove that Mengu-Timur, son of Togan, did not participate in that war.
This article also presents new sources of such authors as Yunini Kutb ad-din Musa ibn Muhammad (640/1242 – 726/1326), Yafi’I Abdulla ibn As’ad (698 – 768 AH) and bibliographic collection of al-Markisi Taki ad-din (died in 845 AH)
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