Guest Rob Posted March 8, 2007 Share Posted March 8, 2007 Skynet 5A/B/C: Citation MoD announces "ground-breaking" satellite Mar 7 2007 5:00PM The Ministry of Defence (MoD) confirmed it is launching a ground-breaking communications satellite. Skynet 5A Satellite is scheduled to be fired off from French Guyana at the weekend and is designed to handle the long-haul communications requirements of Britain's armed forces, reports thepfi.net. The next-generation innovation is expected to usher in a new era of satellite communications for use in military operations and the cutting-edge technology will provide the MoD with secure means of contact in all terrain. Manufactured and managed by a division of Astrium Services, Skynet 5A will be set off from an Ariane launch transporter at the European Space Port and will be followed in later months by the 5B model and an orbiting spare 5C scheduled for space next year. "The best armed forces in the world deserve the best communications service. And that is what we will provide with Skynet 5," commented Malcolm Peto, managing director of Astrium subsidiary Paradigm Secure Communications. He added that the satellite will enable the MoD to deliver critical communications faster and more efficiently. International company Astrium also supplies advanced technology military communication satellites to the ministry of defence in France as part of its framework deal with the French government. Link: Skynet Astrium UK, part d'un projet international: Citation Astrium launches Mercury probe build Published: 28 February 2007 12:00 PM ESA’s Science Programme Committee (SPC), has awarded EADS Astrium a €330m contract to build the Mercury probe BepiColombo, which is scheduled to begin its journey to Mercury in 2013. BepiColombo will consist of three modules: a European orbiter, a Japanese orbiter and a transfer module carrying the two spacecraft to Mercury. The complete unit will have a height of approximately five metres and a mass of about three tonnes, of which about 50 per cent is propellant. The European Mercury Planetary Orbiter (MPO) will be equipped with eleven sophisticated scientific instruments. Flying in a polar orbit, it will study Mercury for at least a year, imaging the planet’s surface, generating height profiles, and collecting data on Mercury’s composition and atmosphere. The Japanese Mercury Magnetospheric Orbiter (MMO) will investigate the planet’s magnetic field with its five on-board instruments. Astrium in Germany as prime contractor is responsible for the entire three-section spacecraft, leading an industrial core-team including Astrium in the UK and Alcatel Alenia Space in Italy. Attitude and orbit control design and development is also under German responsibility and the integration of the engineering model will also take place in Germany. In the UK, Astrium is responsible for the electrical and chemical propulsion system as well as the complete MPO spacecraft structure. Alcatel Alenia Space will develop the MPO electrical power, thermal control and communications systems and is responsible for the integration and test activities. Astrium in France will develop the on-board software building on experienced gained on Rosetta, Mars Express and Venus Express. One of the greatest challenges facing Astrium engineers is preparing BepiColombo for the extreme temperatures it will encounter. Close to Mercury, solar radiation is up to ten times stronger than on Earth, with temperatures of up to 470oC on the planet’s surface. Experts at Astrium and at Alcatel Alenia Space will use a variety of techniques to protect the electronics and scientific instruments from the extreme heat including a newly designed insulating multi-layer blanket whose top layer is likely to be made using ceramic-fibres. A radiator will release the heat from the probe’s interior into space, whose design makes it less sensitive to the thermal infrared radiation emitted by the planet’s surface. In addition the spacecraft will use special solar arrays capable of supplying power even when temperatures reach 250oC. The combination of a conventional chemical propulsion system with an innovative ion propulsion system will provide the required thrust on BepiColombo’s long journey. Several swing-by manoeuvres are planned to reach Mercury. During these manoeuvres, BepiColombo will be accelerated using the gravity fields of the Moon, Earth and Venus. BepiColombo is scheduled to reach its destination in 2019 and enter into a polar orbit after two further swing-by manoeuvres at Mercury. Scheduled to explore Mercury for at least 12 months, the spacecraft’s mission may be extended by a further year. To date, planetary researchers know very little about the hottest planet in our solar system. Most of the detailed data comes from NASA’s Mariner 10 spacecraft which performed three flybys in the seventies and was able to image part of the planet. Link: Astrium UK, part d'un projet international Deuxieme satellite du SSTL pour Galileo: Citation ESA award SSTL contract to build a second GIOVE-A 5th March 2007 Today, the European Space Agency (ESA) awarded a contract to Surrey Satellite Technology Ltd (SSTL) to build a second satellite for the Galileo satellite navigation system. Named GIOVE-A2, the new satellite will be based on the company’s proven GIOVE-A medium Earth orbit satellite technology. GIOVE-A2 will help maintain the critical International Telecommunications Union (ITU) frequency filing secured by its predecessor for a further 27 months and facilitate further development of ground equipment. SSTL’s Executive Chairman, Sir Martin Sweeting, commented, “With GIOVE-A, SSTL was able to provide ESA with a vital part of the Galileo system exactly when it was needed. GIOVE-A has performed well in orbit and we are very pleased to be working with ESA again on a second GIOVE satellite”. Environmental monitoring is also an important ongoing mission objective for the new satellite. GIOVE-A was the first European satellite to be launched into medium Earth orbit (MEO) and it carries two environmental monitors. These units have been operated almost continuously since launch and are gathering vital data to characterise the Galileo orbit environment that will help in the design of the full constellation. The new satellite will carry some enhancements over GIOVE-A that will allow additional signals to be generated and received on the ground. The aim will be to provide early in-orbit experimentation on the common baseline L1 open service signals recently recommended by the EU and US. In the future, these open service signals will provide free of charge position and timing competitive with other GNSS systems to users. GIOVE-A was designed to broadcast Galileo signals from space so that Europe could claim the frequencies filed for Galileo with the ITU. Following a rapid development programme that started in the second half of 2003, the satellite was designed, built, tested and launched before the end of 2005. At 17:25 GMT on the 12th January 2006, the first Galileo signals were transmitted from the satellite. In March, ESA was able to confirm that it had brought the Galileo-related frequency filings into use, three months ahead of the official ITU deadline. In addition to the frequency filing activity, GIOVE-A was required to broadcast navigation signals that have allowed testing of Galileo ground equipment during its ongoing 27-month mission, which is an essential activity to encourage uptake of Galileo in the user communities. GIOVE-A also assisted ESA’s clock characterisation experiments. A highly accurate model was built from tracking the position of GIOVE-A that enabled ESA to test the performance of the satellite’s state-of-the-art onboard Rubidium atomic frequency clock. Initial results demonstrated the clocks to be highly accurate, proving technology that will be integral to all future Galileo satellites including GIOVE-A2. The Royal Institute of Navigation recognised the contribution that GIOVE-A had made to navigation with the Harold Spencer Award, presented to SSTL by HRH Duke of Edinburgh in October of last year. Achievements in GIOVE-A also earned SSTL a “Times Higher Education Supplement’s Outstanding Contribution to Innovation & Technology” award. Link: SSTL Quote Link to comment Share on other sites More sharing options...
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