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Arenas de Iguña, Spain

Brosch N.,Tel Aviv University | Barstow M.,University of Leicester | Chirivella J.,Sener Ingenieria y Sistemas | Chirivella J.,Complutense University of Madrid
Astrophysics and Space Science | Year: 2014

This paper summarizes 17 talks presented during the Technological sessions at the “Challenges in UV Astronomy” conference. It is based on summaries submitted by the presenters, on the slides of their talks, on notes written by the authors, and on additional material kindly submitted to the lead author. In many instances the summaries were written by the presenters themselves and are included as-submitted to the authors with just minor editorial interference. In other cases one of the editors wrote the summary based on their notes and on the files of the actual presentations. The contributions are placed in the general context of the current knowledge in the field. The sessions were devoted to: [a] detectors, [b] optics, [c] integration and verification procedures for vacuum UV instruments and [d] calibration and archival research. A cautionary note: this is not a regular article in these proceedings presenting one idea, an experiment, of a result. It is rather a distillation of what was presented at the NUVA/ESO/IAG meeting at the sessions deemed technological, therefore it will lack an overall coherence although the individual sections and subsections should be logically connected. © 2014, Springer Science+Business Media Dordrecht. Source

Branco J.,GMV Inc | Barrena V.,GMV Inc | Olmos D.E.,GMV Inc | Castellani L.T.,Sener Ingenieria y Sistemas | Cropp A.,European Space Agency
Annual Review of Earth and Planetary Sciences | Year: 2015

PROBA-3 will demonstrate technologies and techniques for precise Formation Flying of two spacecraft. This paper describes its Formation Flying Navigation system for relative position and velocity determination. A Coronagraph spacecraft carries fine relative position metrology and higher-thrust propulsion, and an Occulter spacecraft carries fine low thrust actuators. The two spacecraft communicate data to each other through an Inter-Satellite Link with an associated delay. A relative GPS solution is also available for a period around the perigee pass. The Formation Flying Navigation system is part of the Formation Flying Software which commands the formation. It collects data from the sensors and actuation commands, synchronizes them to a common correction time, and processes them in an Extended Kalman Filter which makes use of a model of the dynamics of relative motion in elliptical orbits. This article provides an overview of the mission and the challenges posed to the relative navigation function design, and describes, in high level, the developed solutions that constitute the preliminary design of the Formation Flying Navigation System. Special emphasis is given to the solutions for handling the synchronization and processing of information from a high number of sources, in two spacecraft which communicate through an Inter Satellite link and are thus subject to significant latencies. © Springer International Publishing Switzerland 2015. Source

Kerr M.,DEIMOS Space S.L.U. | Haya R.,DEIMOS Space S.L.U. | Penin L.F.,DEIMOS Space S.L.U. | de Zaiacomo G.,DEIMOS Space S.L.U. | And 2 more authors.
AIAA Guidance, Navigation, and Control Conference 2012 | Year: 2012

The Intermediate eXperimental Vehicle (IXV) re-entry GNC is tasked with stabilising and manoeuvring the IXV from the Entry Interface Point (EIP, 120 km altitude) suborbital trajectory conditions to the deployment of a 3 stage (supersonic drogue, subsonic drogue and a main parachute) parachute system. The re-entry GNC is comprised of the Guidance, Navigation and Control functions, which are scheduled via a Flight Management function that interfaces the GNC with the vehicle's mode vehicle management (MVM). Within re-entry GNC responsibilities there is also the design and validation of the Descent and Recovery System (DRS) triggering algorithm, which autonomously triggers the extraction of the supersonic parachute. The IXV is a lifting body with a lift-to-drag ratio of 0.7 in the hypersonic regime and, distinct from other re-entry vehicles such as ARD and Orion, is actuated through the combination of two body flaps mounted at the aft windward side of the vehicle and RCS thrusters. The challenges for the IXV re-entry GNC system design are common to those for re-entry vehicles performing a first flight, with the re-entry GNC required to be robust to high levels of uncertainty in the vehicle dynamics. This paper describes the IXV re-entry G&C and DRS triggering algorithms at the current IXV programme status of Phase D, including the assessment of the re-entry GNC performance using the IXV functional engineering simulation developed for the IXV programme. s© 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Source

Rodriguez-Colina E.,Metropolitan Autonomous University | Gil-Leyva D.,Sener Ingenieria y Sistemas | Marzo J.L.,University of Girona | Ramos R. V.M.,Metropolitan Autonomous University
Telecommunication Systems | Year: 2014

Inter-satellite links (ISL) are a useful technology to transmit data to space stations and to communicate between satellites. However, there are serious limitations due to long delays and poor channel performance, resulting in high bit error rates (BER). In this paper, parallel transmission and the scaling of the Transport Control Protocol (TCP) window in free space optics (FSO) communications are analyzed in order to overcome these disadvantages in optical inter-satellite links. Latency and BER are the dominant effects that determine link performance. Thus, a physical, link, network and transport cross-layer analysis for FSO over ISL is presented in this paper. This analysis shows the advantages and disadvantages of using optical parallel transmission and TCP window scaling for free space optical links between stations and satellite constellations. The key contribution of this work is to simulate the effects of the BER and to link the results to packet error rate (PER) to determine the goodput for TCP transmissions by using a cross-layering approach. The results give evidence that wavelength division multiplexing (WDM) can mitigate the effects of long delay and high BER for a FSO communication using TCP. © 2013 Springer Science+Business Media New York. Source

Ismail M.,Sener Ingenieria y Sistemas | Ismail M.,Zagazig University | Ismail M.,Polytechnic University of Catalonia | Rodellar J.,Polytechnic University of Catalonia | Casas J.R.,Polytechnic University of Catalonia
Advances in Materials Science and Engineering | Year: 2016

This paper introduces a recent seismic isolation system, named Roll-in-Cage (RNC) isolator, for efficient protection of bridges against destructive earthquakes. The RNC isolator is a rolling-based isolation system with several integrated features in a single unit providing all the necessary functions of vertical rigid support, horizontal flexibility, full stability, hysteretic energy dissipation, and resistance to minor vibration loads. Besides, it is distinguished by a self-stopping (buffer) mechanism to limit the peak bearing displacement under abrupt severe excitations, a linear gravity-based self-recentering mechanism to prevent permanent dislocations after excitations, and a notable resistance to axial tension. A three-span box-girder prestressed concrete bridge is investigated under a set of different destructive real and synthetic earthquakes including near-fault, long-period, and pulse-like ground motions. As a performance measure, the responses of isolated and nonisolated cases are compared. In addition, the RNC isolator's behavior is then compared with those of other isolation systems including HDB, FPS, and LRB. The results confirmed that the RNC isolator has a superior behavior in achieving a balance between the peak displacements and accelerations of the isolated deck, relative other isolation systems, besides being the most (relatively) efficient isolator in the great majority of studies performed. © 2016 Mohammed Ismail et al. Source

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