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Epenoy R.,French National Center for Space Studies
Journal of Guidance, Control, and Dynamics | Year: 2011

This paper focuses on the issue of minimum-fuel rendezvous between an active chaser satellite with continuousthrust capability and a passive target satellite. It is first formalized as an optimal control problem subject to a collision-avoidance constraint on the path of the chaser satellite. Then, a new method for dealing with this state constraint is built by adapting to the optimal control framework a recently developed approach for solving inequality-constrained nonlinear programming problems. The resulting method implies solving a sequence of unconstrained optimal control problems, the solutions of which converge toward the solution of the original problem. Convergence of the method is proved, and its efficiency is demonstrated through numerical results obtained in the case of a rendezvous in a highly elliptical orbit. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc. Source

Agency: Cordis | Branch: H2020 | Program: IA | Phase: GALILEO-1-2015 | Award Amount: 4.87M | Year: 2016

The HELIOS project aims at providing a Second Generation range of Beacons (SGB) and associated antennas designed to operate with the full capability of the new Meosar Cospas/Sarsat (C/S) International Programme (a satellite-based Search And Rescue (SAR) distress alert detection and information distribution system), embedded in the Navigation Satellite Systems as GALILEO. The Search & Rescue community is at a turn of its history. New satellite systems develops the MEOSAR constellation of Cospas-Sarsat system, EGNOS improves significantly the performance of localization introducing new capabilities and new operations impossible before, GALILEO unique differentiation with the RLS added to the performance of the system will contribute to save more lives at sea and on land. The key objectives of the HELIOS project are: 1 - Defining, developing Products (beacons and associated antennas) compatible with EGNSS & SAR services and latest end-users requirements. 2 - GALILEO EGNSS & SAR System validation. 3 - Certifications for commercialization. The HELIOS consortium composed of Orolia, Cobham aerospace communications, CNES, SIOEN, Air France, and Airbus, is involved in different relevant international working groups (Cospas-Sarsat, ICAO, EUROCAE), and will ensure that the development phase of the SGB will be in line with the compatibility and interoperability required by the Cospas-Sarsat. Gathering the knowledge of major players recognized in their industry worldwide, the HELIOS partners project will give the vehicle to the European Industry to lead the way for safer, more innovative systems responding to current and evolving market problems.

Agency: Cordis | Branch: H2020 | Program: CSA | Phase: COMPET-09-2014 | Award Amount: 862.06K | Year: 2015

In January 2014, the ISEF participants insisted on the importance of fostering international cooperation for additional space exploration projects. The partners of IRENA (International Re-Entry demoNstrator Action), including major space agencies involved in ISEF and ISECG, are convinced of the need for demonstrators in atmosphere entry/re-entry and of the potential for international cooperation in this area. IRENA mainly aims at: - creating a cluster of European and international stakeholders to study two types of demonstrators aimed at developing entry/re-entry technologies and suitable for other enabling technologies - jointly defining two technology demonstrator projects relevant for international cooperation - contributing to a European position for ISEF and - disseminating the results and preparing the next steps. To achieve these objectives, IRENA will rely on an international and complementary team: four major European and international space agencies (CNES, DLR and JAXA as beneficiaries and NASA as a 3rd party), the two European industry leaders in entry/re-entry and space exploration (Astrium, Thales Alenia Space) and a research institute expert in dissemination and exploitation. IRENA will build on a cooperative approach to jointly define the projects, on feasibility and cost assessment studies and on implementation assessment studies (governance, funding, international cooperation). Five workshops including one in Japan, the USA and two based on Concurrent Engineering will be used to support the work. IRENAs objectives have been chosen to explicitly meet the main work programmes requirements i.e. to be in line with ISEF recommendations, to involve international countries active in space exploration, to create a cluster around several demonstrator projects, to define these projects and discuss how to build them, to target enabling technologies and to include workshops and information events.

Agency: Cordis | Branch: H2020 | Program: CSA | Phase: COMPET-09-2014 | Award Amount: 1.01M | Year: 2015

The objective of this proposal is to investigate the necessary demonstration activities in order to mature technologies for nuclear electric propulsion (NEP) systems that is considered one of the key enabler to allow deep exploration and science missions both manned and unmanned. The DEMOCRITOS projects aims to define three Demonstrator Concepts in regards to NEP technologies: 1. Detailed preliminary designs of ground experiments that will allow maturing the necessary technologies in the field of MW level nuclear electric propulsion. The project will investigate the interaction of the major subsystems (thermal, power management, propulsion, structures and conversion) with each other and a (simulated) nuclear core providing high power, in the order of several hundred kilowatts. 2. Nuclear reactor cost studies and simulations to provide feedback to the simulated nuclear core of DEMOCRITOS ground experiments as well as conceptualize the concept of nuclear space reactor and outline the specifications for a Core Demonstrator, including an analysis of the regulatory and safety framework that will be necessary for such a demonstration to take place on the ground. 3. System architecture and robotic studies that will investigate in detail the overall design of a high power nuclear spacecraft, together with a pragmatic strategy for assembly in orbit of such a large structure coupled with a nuclear reactor. Additionally, the project partners will define a programmatic plan, insuring that the demonstrators can be built, tested, and reach the established ambitious objectives, this with a clear organization between international partners and with costs shared in a sustainable way. DEMOCRITOS aims to form a cluster around NEP related technologies by organizing an international workshop and invite external stakeholders to propose ideas for the ground and flight demonstrators or possibly join in the effort to realize the ground demonstrator experiments.

Agency: Cordis | Branch: H2020 | Program: RIA | Phase: ICT-06-2014 | Award Amount: 2.90M | Year: 2015

VITAL is an ambitious proposal addressing the combination of Terrestrial and Satellite networks by pursuing two key innovation areas, by bringing Network Functions Virtualization (NFV) into the satellite domain and by enabling Software-Defined-Networking (SDN)-based, federated resources management in hybrid SatCom-terrestrial networks. Enabling NFV into SatCom domain will provide operators with appropriate tools and interfaces in order to establish end-to-end fully operable virtualised satellite networks to be offered to third-party operators/service providers. Enabling SDN-based, federated resource management paves way for a unified control plane that would allow operators to efficiently manage and optimise the operation of the hybrid network. While innovations pursued by VITAL are transversal, the project will primarily focus on three key application scenarios: Satellite Virtual Network Operator (SVNO) services, Satellite backhauling and hybrid telecom service delivery. The solutions developed in VITAL will bring, through flexible integration of satellite and terrestrial segments, improved coverage, optimised communication resources use and better network resilience, along with improved innovation capacity and business agility for deploying communications services over combined networks. VITAL will address the development of a hybrid architectural framework, the required mechanisms to enable virtualization of SatCom network components, including performance optimisation and implementation of a number of virtualised functions, and the design of an SDN-enabled, federated resources management framework, embedding strategies and algorithmic solutions to provide end-to-end communication services. Proof of Concept validation of VITAL solutions and enabling technologies through a combination of real prototypes and emulators are also envisaged. The project aims to impact standardization initiatives and will contribute to open platform initiatives for SDN/NFV deployments.

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