Launch of the Gaia Satellite, an ESA Project with Major Participation by SENER
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PRESS RELEASE Launch of the Gaia satellite, an ESA project with major participation by SENER Madrid, December 17, 2013 – The SENER engineering and technology group has played a major role in the Gaia project, a scientific mission of the European Space Agency that is set to launch into space on Thursday, December 19. For five years, Gaia will observe and catalog a billion stars, 1% of those populating the Milky Way, through its two telescopes and their corresponding instruments. This mission represents a qualitative leap forward in the field of astrophysics, as it is expected to multiply by 10,000 the astrometrical data (position, distance, relative velocities and photometric data) currently available to the scientific community that was collected in the 1980s by the Hipparcos scientific mission. Gaia will allow scientists to draw a 3D map of our galaxy at an unprecedented level of accuracy and obtain data on other nearby galaxies such as Andromeda. In its sweep of the celestial sphere, which will take place twice a year, it is expected to record data on thousands of new objects, providing valuable information for all the subfields of astronomy and cosmology. SENER has made a significant contribution to this program as it was responsible for both the M2M device, which allows the telescopes to focus and includes a precision mechanism and its associated electronic circuitry, representing one of SENER's specialties, and for the deployable sunshield, the spacecraft's largest component. This device has no technological precedents; never before has a synchronously deployable thermal shield of this size been built for a spacecraft. DEPLOYABLE SUNSHIELD — AN ENGINEERING CHALLENGE SENER designed, integrated and verified the satellite's sunshield, which measures 10.4 meters in diameter and contains 12 identical frames, designed to deploy simultaneously, that support two thermal covers arranged in parallel. The sunshield was designed to provide a low temperature environment for the satellite's instruments and ensure the thermal stability of the optical components, which can only function at 170ºC below zero throughout the entire mission, in order to guarantee precise focusing of telescopes. To ensure its performance, the surface of the sunshield must be fully tensed when deployed; any wrinkles or imperfections can result in a difference in the thermal gradient for a given area of the satellite. The sunshield opens after launch and must remain open throughout the entire mission to protect Gaia from solar radiation. At the same time, a series of solar panels placed on the Sun-side of the satellite will provide Gaia with electricity. Work on its design began in 2006, although various technological components had already been designed to meet the needs of such a complex structure: the mechanical tensing system for the insulating thermal covers and the transmission mechanism that communicates between these systems and enables simultaneous deployment. From the beginning, the main challenges were, on the one hand, the system's structural components, which have to remain straight regardless of the extreme temperature differences (up to 150ºC) between the Sun-side and the dark side of the satellite, and, on the other hand, the thermal covers. These are made out of a special aluminized plastic sheet and comprise a total of seven layers; two used on the Sun-side and five on the dark side. These insulating blankets must remain tightly fixed to the spacecraft during launch to withstand the vibrations produced by the Soyuz rocket and must be deployed smoothly once in orbit. More information: Oihana Casas. Communication Office. SENER Tel. (+34) 91 807 73 18 / (+34) 679 31 40 85 www.sener.es In 2008, the project's team of engineers focused on the SDE electronic units which control the sunshield's motors, deployment system and testing of the entire system. According to SENER Space Director Diego Rodriguez, one of the major challenges in the design of the sunshield was the testing on the ground, which required a full recreation of space conditions in terms of gravity, vacuum and temperature for a structure that was nearly 11 meters in diameter. To recreate these conditions, SENER carried out testing both in Spain and France and finally in French Guiana at the Kourou Space Centre. It was here where the spacecraft was assembled before its upcoming launch. M2M SUBSYSTEM In addition, SENER developed the positioning subsystem for the telescopes' secondary mirrors, known as M2M. This device connects the reflecting mirror to the optical bench and contains both the M2MM and the electronic unit, known as MDE. The M2MM is one of the most critical precision mechanisms as it corrects any misalignments in the telescope, especially those that may occur after launch. This adjustment is performed automatically by way of an on-board computer. This advanced mechanism ensures movement of the mirrors along five degrees of freedom at sub- micrometric precision (i.e. it can rotate almost in any direction) and is designed to withstand launching loads without hold down. It employs a system patented by SENER and unique to the market; in fact, SENER is also building a similar mechanism for another ESA scientific mission, Euclid. The importance of Gaia for the international scientific community is indisputable. SENER has made a decisive contribution to this mission. About SENER SENER is a private engineering and technology group founded in 1956, which seeks to offer its clients the most advanced technological solutions and which enjoys international recognition, thanks to its independence and its commitment to innovation and quality. SENER has a workforce of nearly 5,500 professionals working in its offices in Algeria, Argentina, Brazil, South Korea, Chile, China, Colombia, United Arab Emirates, Spain, the United States, India, Japan, Mexico, Poland, Portugal and the United Kingdom. The Group has a turnover of €1.175 billion (2012 data). SENER engages in the specific activities of Engineering and Construction, and also has industrial holdings in companies involved in Energy and Environment, as well as in Aeronautics. In Engineering and Construction, SENER has become a world leader in the Aerospace, Infrastructure and Transport, Power and Processes, and Marine Engineering sectors. In the Space sector, SENER develops components and systems for the flight segment in three areas: precision mechanisms, optical payloads and GNC systems. • In the area of precision mechanisms, SENER has developed projects such as complete system of medium- and high-gain antennas for the BepiColombo satellite, the antenna subsystem for the Solar Orbiter scientific satellite, the high-gain pointing mechanism for the Mars Science Laboratory, the deployable sunshield and the M2M secondary mirror positioning mechanism for the Gaia mission, as well as the scan, calibration and shutter mechanisms for Meteosat Third Generation (MTG). • In the area of optical payloads, the group has carried out projects such as the ultraviolet camera for the World Space Observatory Satellite, a collaborative project between Spain and Russia in which SENER is responsible for delivering the complete camera for its subsequent integration into the satellite, or the SEOSAT/Ingenio primary payload, a high performance-high resolution camera for Earth. • Lastly, in Guidance, Navigation and Control Systems (GNC), SENER has an important portfolio of projects, such as the Herschel and Planck Attitude and Orbit Control System (AOCS), for which SENER has been a first level contractor, the development, integration and supply of testing equipment for the MTG AOCS SCOE subsystem, and the Proba 3 project, where it is responsible for the complete mission as the principal contractor. Along with the above areas, SENER also carries out work on instrumentation for microgravity, life support systems and payload electronics, for applications such as the European Space Agency's MARES, MELISSA and LISA Technology Package projects. Follow us on: More information: Oihana Casas. Communication Office. SENER Tel. (+34) 91 807 73 18 / (+34) 679 31 40 85 www.sener.es .