COVER BUL-121 4/19/05 10:25 AM Page 1 www.esa.int number 121 - february 2005 Member States Etats membres Austria Allemagne Belgium Autriche Denmark Belgique Finland Danemark France Espagne Germany Finlande Ireland France Italy Irlande Netherlands Italie Norway Norvège Portugal Pays-Bas Spain Portugal Sweden Royaume-Uni Switzerland Suède SPACE FOR EUROPE United Kingdom Suisse ESA bulletin 121 - february 2005 Contact: ESA Publications Division c/o ESTEC, PO Box 299, 2200 AG Noordwijk, The Netherlands Tel (31) 71 565 3400 - Fax (31) 71 565 5433 Visit ESA Publications at: http://www.esa.int INSIDE COVER-B121 4/19/05 9:56 AM Page 2 european space agency Editorial/Circulation Office ESA Publications Division ESTEC, PO Box 299, Noordwijk The European Space Agency was formed out of and took over the rights and obligations of, the two earlier European Space Organisations – the 2200 AG The Netherlands European Space Research Organisation (ESRO) and the European Organisation for the Development and Construction of Space Vehicle Launchers Tel.: (31) 71.5653400 (ELDO). The Member States are Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Norway, Portugal, Spain, Editors Sweden, Switzerland and the United Kingdom. Canada is a Cooperating State. Bruce Battrick Barbara Warmbein In the words of its Convention: the purpose of the Agency shall be to provide for and to promote for exclusively peaceful purposes, co-operation among Design & Layout European States in space research and technology and their space applications, with a view to their being used for scientific purposes and for operational Isabel Kenny space applications systems: Advertising (a) by elaborating and implementing a long-term European space policy, by recommending space objectives to the Member States, and by concerting Barbara Warmbein the policies of the Member States with respect to other national and international organisations and institutions; The ESA Bulletin is published by the European Space (b) by elaborating and implementing activities and programmes in the space field; Agency. Individual articles may be reprinted provided (c) by co-ordinating the European space programme and national programmes, and by integrating the latter progressively and as completely as the credit line reads ‘Reprinted from ESA Bulletin’, plus date of issue. Signed articles reprinted must bear the possible into the European space programme, in particular as regards the development of applications satellites; author’s name. Advertisements are accepted in good (d) by elaborating and implementing the industrial policy appropriate to its programme and by recommending a coherent industrial policy to the faith; the Agency accepts no responsibility for their Member States. content or claims. Copyright © 2005 European Space Agency The Agency is directed by a Council composed of representatives of the Member States. The Director General is the chief executive of the Agency and Printed in the Netherlands ISSN 0376-4265 its legal representative. The ESA HEADQUARTERS are in Paris. The major establishments of ESA are: THE EUROPEAN SPACE RESEARCH AND TECHNOLOGY CENTRE (ESTEC), Noordwijk, Netherlands. THE EUROPEAN SPACE OPERATIONS CENTRE (ESOC), Darmstadt, Germany ESRIN, Frascati, Italy. Chairman of the Council: P. Tegnér Director General: J.-J. Dordain agence spatiale européenne L’Agence Spatiale Européenne est issue des deux Organisations spatiales européennes qui l’ont précédée – l’Organisation européenne de recherches spatiales (CERS) et l’Organisation européenne pour la mise au point et la construction de lanceurs d’engins spatiaux (CECLES) – dont elle a repris les droits et obligations. Les Etats membres en sont: l’Allemagne, l’Autriche, la Belgique, le Danemark, l’Espagne, la Finlande, la France, l’Irlande, l’Italie, la Norvège, les Pays-Bas, le Portugal, le Royaumi-Uni, la Suède et la Suisse. Le Canada bénéficie d’un statut d’Etat coopérant. Selon les termes de la Convention: l’Agence a pour mission d’assurer et de développer, à des fins exclusivement pacifiques, la coopération entre Etats européens dans les domaines de la recherche et de la technologie spatiales et de leurs applications spatiales, en vue de leur utilisation à des fins scientifiques et pour des systèmes spatiaux opérationnels d’applications: Cover: The surface of Titan, as seen for the first time by ESA’s Huygens probe. See article on page 6. (a) en élaborant et en mettant en oeuvre une politique spatiale européenne à long terme, en recommandant aux Etats membres des objectifs en matière spatiale et en concertant les politiques des Etats membres à l’égard d’autres organisations et institutions nationales et internationales; (b) en élaborant et en mettant en oeuvre des activités et des programmes dans le domaine spatial; (c) en coordonnant le programme spatial européen et les programmes nationaux, et en intégrant ces derniers progressivement et aussi complètement que possible dans le programme spatial européen, notamment en ce qui concerne le développement de satellites d’applications; (d) en élaborant et en mettant en oeuvre la politique industrielle appropriée à son programme et en recommandant aux Etats membres une politique industrielle cohérente. L’Agence est dirigée par un Conseil, composé de représentants des Etats membres. Le Directeur général est le fonctionnaire exécutif supérieur de l’Agence et la représente dans tous ses actes. Le SIEGE de l’Agence est à Paris. Les principaux Etablissements de l’Agence sont: LE CENTRE EUROPEEN DE RECHERCHE ET DE TECHNOLOGIE SPATIALES (ESTEC), Noordwijk, Pays-Bas. LE CENTRE EUROPEEN D’OPERATIONS SPATIALES (ESOC), Darmstadt, Allemagne. ESRIN, Frascati, Italy Président du Conseil: P. Tegnér Directeur général: J.-J. Dordain www.esa.int CONTENTS-B121 3/3/05 10:05 AM Page 3 6 11 21 Europe Arrives at the New Cluster – AmerHis:The First Frontier A microscope and a telescope Switchboard in Space – The Huygens landing on Titan for studying space plasmas 28 36 59 Satellite Navigation, Wireless Frequency Management ‘Maxwell’ Networks and the Internet for ESA’s Missions – A New State-of-the-Art EMC Test Facility bulletin 121 - february 2005 Contents Europe Arrives at the New Frontier Columbus: Ready for the International Space Station – The Huygens landing on Titan 6 Bernado Patti et al. 46 Cluster Software Engineering: Are we getting better at it? – A microscope and a telescope for studying space plasmas Michael Jones 52 Harri Laakso et al. 11 ‘Maxwell’ AmerHis:The First Switchboard in Space – A New State-of-the-Art EMC Test Facility Manfred Wittig et al. 21 Jean-Luc Suchail, Alexandre Popovitch & Philippe Laget 59 Satellite Navigation, Wireless Networks and the Internet Programmes in Progress 64 Felix Toran et al. 28 News – In Brief 80 Frequency Management for ESA’s Missions Edoardo Marelli & Enrico Vassallo 36 Publications 88 www.esa.int esa bulletin 121 - february 2005 1 Lebreton 3/3/05 10:08 AM Page 6 Europe Arrives at the New Frontier – The Huygens Landing on Titan Lebreton 3/3/05 10:08 AM Page 7 Europe at the New Frontier n 14 January 2005, after a marathon seven-year journey through the Solar System aboard the Cassini spacecraft, ESA’s Huygens probe successfully descended through the atmosphere of Titan, Saturn’s largest moon, and landed safely on its surface. It was Omankind’s first successful attempt to land a probe on another world in the outer Solar System. Following its release from the Cassini mothership on 25 December, Huygens reached Titan’s outer atmosphere after 20 days and a 4 million kilometre cruise. The probe started its descent through Titan’s hazy cloud layers from an altitude of about 1270 km at 09:06 UTC. During the following three minutes, Huygens had to decelerate from 18 000 to 1400 km per hour. A sequence of parachutes then slowed it to less than 300 km per hour. At a height of about 160 km, the probe’s scientific instruments were exposed to Titan’s atmosphere for the first time and Huygens started to transmit its radio signal to Cassini at 09:12 UTC (spacecraft event time). The Huygens radio signals also arrived on Earth, but 67 min later as a faint tone that was detectable by large radio telescopes. At about 120 km altitude, the main parachute was jettisoned and replaced by a smaller one to complete the descent. The Huygens radio signal was detected on Earth at about 11:20 CET by the 110-m Robert Byrd Green Bank Telescope in West Virginia. About 2 hours later, the probe’s signal was picked-up by telescopes in Australia, which indicated that Huygens had landed and continued to transmit after landing. Cassini listened to Huygens for 4h 36 min and then transmitted the Huygens data to Earth via NASA’s Deep Space Network once the Huygens mission was over. The first scientific data arrived at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany at 17:19 CET, having also taken 67 min to travel across space. An hour later, the data indicated that Huygens had landed safely at 12:39 CET and had transmitted data for 72 min from Titan’s surface. Thirty-image composite of Titan’s surface from altitudes varying between 13 and 8 kilometres (Credit: ESA/NASA/JPL/University of Arizona) www.esa.int esa bulletin 121 - february 2005 7 Lebreton 3/3/05 10:08 AM Page 8 Science The Descent “This is a great achievement for Europe and its US partners in this ambitious Huygens was expected to provide the first international endeavour to explore the Saturnian system,” said Jean-Jacques Dordain, direct and detailed sampling of Titan’s ESA’s Director General. “The teamwork in Europe and the USA, between scientists, atmospheric chemistry and the first industry and agencies has been extraordinary and has set the foundation for this photographs of its hidden surface, and to enormous success”. supply a detailed ‘weather report’.