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Solna, Sweden

Karlsson T.,OHB Sweden AB | Ahlgren N.,OHB Sweden AB | Faller R.,German Aerospace Center | Schlepp B.,German Aerospace Center
SpaceOps 2012 Conference | Year: 2012

The PRISMA in-orbit test-bed was launched in June 2010 to demonstrate strategies and technologies for formation flying and rendezvous. OHB Sweden is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB) with support from DLR, CNES, and DTU. Mission operations are carried out from OHB Sweden's purpose built control-room in Solna, Sweden, using the company's own GNC and platform experts to conduct the mission. As an experimental technology demonstrator a large number of in-orbit experiments were initially planned, with desires exceeding the constraints of available funding. In an effort to extend the use of the satellites and enable more experiments DLR/GSOC offered to temporarily operate the satellites from their control center in Oberpfaffenhofen, Germany, for a period of five months. Control of the spacecraft was transferred to GSOC in March, 2011, after a training period of several months. A number of experiments were executed, including GSOC's own formation flying and autonomous orbit keeping, SSC ECAPS's green propulsion and several different OHB Sweden experiments. Handover back to OHB Sweden was then performed in August the same year, from where the mission continues to be run. Transferring control of a satellite project from one organization to another, including new operational personnel and a new control room, posed a great challenge to both parties. This paper describes the mission concept, the background for the transfer, implementation of a mirrored control room and the process of transferring knowledge from the design and operations team of OHB Sweden to the GSOC operations team. © 2012 by OHB-Sweden AB. Source

Battelino M.,OHB Sweden AB | Svard C.,OHB Sweden AB
SpaceOps 2012 Conference | Year: 2012

RAMSES (Rocket and Multi Satellite EMCS Software) was developed in-house at OHB Sweden (former Space Systems Division at SSC) and has during the past years served a number of different space related projects; e.g. the PRISMA satellite formation flying project at OHB Sweden and DLR GSOC in Germany, the Russian scientific satellite project FOTON-M3 and the sounding rocket programs MASER and MAXUS. Common to all projects is that the RAMSES ground system is used throughout the whole project from development and test up to and including its mission phase. RAMSES is especially suited for projects with short timelines and where cost efficiency is an important driver. The system is deployed within minutes and executes on standard PC hardware. The adaptation of the system to new missions is generally only a matter of populating the system database with mission specific telemetry and telecommand definitions. The functionality within RAMSES is distributed between a number of standalone application nodes executing on one or several PC machines connected to the network. This paper will focus on the design, functionality and advantages of RAMSES compared with other systems on the market. Newly developed functionality concerning archiving and extraction of large amount of data is described. The role of RAMSES through the different phases of the small satellite project PRISMA is also presented. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Source

Rathsman P.,OHB Sweden | Demaire A.,OHB Sweden AB | Rezugina E.,OHB Sweden AB | Lubberstedt H.,OHB System AG | De Tata M.,OHB System AG
Proceedings of the International Astronautical Congress, IAC | Year: 2013

In September 2003, ESA launched the lunar probe SMART-1. Using a single electric thruster providing only 70 mN of thrust, SMART-1 traversed the radiation belts under the worst solar storm conditions ever recorded to successfully reach the Moon in November 2004. Ten years later, the legacy of SMART-1 has been an important contributor to the implementation of the Electra programme, aimed at developing Europe's first all-EP telecommunications satellite. Thanks to the significant mass saving offered by electric propulsion, Electra will be able to host the same payload capability as traditional mid-sized telecom satellites, whilst achieving a much lower launch mass. The paper discusses the challenges associated with the implementation of all-electric propulsion on telecom satellites, and explains how the experiences of SMART-1 and other relevant missions have contributed to Electra. The first Electra mission is planned to be launched in the 2018-2019 timeframe. Source

Kleimark J.,KTH Royal Institute of Technology | Delanoe R.,OHB Sweden AB | Demaire A.,OHB Sweden AB | Brinck T.,KTH Royal Institute of Technology
Theoretical Chemistry Accounts | Year: 2013

The decomposition pathways of ionized ammonium dinitramide (ADN) have been analyzed using the B3LYP and the M06-2X density functional theory methods, coupled cluster theory and the composite CBS-QB3 method. Ionization and subsequent decomposition of the major decomposition products have also been studied. The ADN+ ion dissociates into the stable DN radical and NH4+ with a dissociation enthalpy of 50 kJ/mol. The subsequently formed DN+ ion has an activation enthalpy of 102 kJ/mol for decomposition into N2O, O2 and NO+. A competing pathway for ionization and decomposition of ADN involves the HDN+ ion, which dissociates into NO2 and HNNO2 with a barrier of only 17 kJ/mol. The ionization product HNNO2 is stable toward further decomposition, and the barrier for isomerization to HONNO+ is 167 kJ/mol. The computed adibatic ionization potentials of ADN, HDN, DN and HNNO2 are 9.4, 11.5, 10.2 and 10.9 eV, respectively. The results of the study have implications for the future use of ADN in propellants for electromagnetic space propulsion. © Springer-Verlag Berlin Heidelberg 2013. Source

Mateo-Velez J.-C.,ONERA | Theillaumas B.,Airbus | Sevoz M.,Airbus | Andersson B.,OHB Sweden AB | And 7 more authors.
IEEE Transactions on Plasma Science | Year: 2015

Spacecraft charging in GEO particularly concerns dielectric surfaces that may charge to significant voltages relative to spacecraft ground because of the space environment. Testing materials helps to define the level of risk and to maintain confidence in a spacecraft's immunity to damaging effects. Another factor defining the risk involves numerical simulation of spacecraft charging. Several tools aim to calculate surface charging, which is particularly hazardous in harsh environments produced by geomagnetic sub storms, where particles in the energy range of a few to hundreds of kiloelectronvolts are present. The main codes include Nascap-2k, Spacecraft plasma Interaction Software (SPIS), MUSCAT, and Coulomb-2. They use different numerical and sometimes physical models and cross checking their results is a necessary process to achieve better confidence in simulations performed by spacecraft prime manufacturers. The objective of this paper is to simulate different GEO spacecraft configurations with NASA Charging Analyzer Program at geosynchronous orbits (a 1980s to 1990s predecessor to Nascap-2k) and SPIS and to compare the results, both in terms of absolute and differential potentials. The first section concerns the SCATHA spacecraft. The second part of this paper compares efforts to model a modern telecom spacecraft. Finally, we conclude on the reliability of the simulations performed and possible areas for modeling improvement. © 1973-2012 IEEE. Source

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