German Space Research Articles

Verification of new technologies as main task of the communication payload of the Heinrich-Hertz mission

In the space business, there is typically a quite long period from the design and development of new technologies to their commercial use. Even comprehensive tests on ground cannot replace long-lasting experiments and tests in space. Such IOV (In Orbit Verification) activities provide the scientific basis for the introduction and application of new technologies and the necessary heritage for commercial satellite programs. The Heinrich-Hertz mission of a geostationary communication satellite with a planned life time of 15 years lead by the German Space Administration (DLR) establishes a valuable basis to verify new technologies scientifically in orbit over a long period of time and to gain heritage regarding their performance in space [1]. In addition, research institutes and the industry are enabled to perform numerous scientific and technological experiments over the full life time of 15 years. With this approach of the mission, the German Space Administration offers to the German satellite industry an outstanding advantage and gain in knowledge for the development of new communication technologies and their applications. The launch of the satellite is envisaged for 2016. The technical feasibility of the overall program was successfully demonstrated within a Phase A study. The major tasks for the payload responsible during Phase A have been: (1) survey and assessment of all proposed IOV-technologies, (2) development of a payload concept for the scientific-technical verification of the IOV-technologies.

Navigation and Control of the PRISMA formation: In-Orbit Experience

AbstractThis paper presents flight results and lessons learned from the Spaceborne Autonomous Formation Flying Experiment (SAFE) conducted by the German Space Operations Center in the frame of the Swedish PRISMA mission. SAFE represents one of the first demonstrations in low Earth orbit of an advanced guidance, navigation and control system for dual-spacecraft formations. Innovative techniques based on carrier-phase differential GPS, relative eccentricity/inclination vectors and impulsive maneuvering are validated and tuned in orbit to achieve centimeter accurate real-time relative navigation, reliable formation keeping at the meter level and flexible formation reconfiguration capabilities.

Language attitudes, migrant identities and space

In a previous paper (Liebscher and Dailey-O'Cain, Dialect use and discursive identities of migrants from the west in eastern Germany, Palgrave Macmillan, 2009), we posited that attitudes toward language are not merely static thoughts in people's minds, but are constantly constructed in interaction. Following on this work, in this paper we investigate the ways in which German-speaking migrants and their descendants in urban Canada use language attitudes in interaction to construct a specifically German space within Canada. Our focus is on their attitudes toward each of the various languages and language varieties present in the participants' linguascape: German dialects, standard German and English, and code-mixing, and in our analysis, we observe the ways that these migrants negotiate who has authority over these forms, as well as how attitudes can shift when speakers' connection to their country of origin is interrupted through migration. Though the direct focus of the research questions we address in this paper is on what it means to be German in urban Canada, we also address broader issues of how urban minority groups construct and maintain minority identities after migration.

European small geostationary communications satellites

Hispasat Advanced Generation 1 (HAG1) is the first satellite using the SGEO platform, which is under the development in the ESA Artes-11 program. Since the last presentation in the IAC 2007, a European industrial consortium led by OHB has completed the mission and spacecraft design. The platform Preliminary Design Review has been carried out in May 2008. The customer for the first mission is a commercial operator—Hispasat. The contract was signed in December 2008 and the satellite will be launched in 2012. To give confidence to the customer, SGEO platform will use up to date flight proven technologies. HAG1 carries 20/24 Ku-band and 3/5 Ka-band transponders to provide commercial services. Some innovative payload technologies will also be flown on board of HAG1 to gain in-orbit heritage. SGEO has also been selected as the baseline platform for the ESA Data Relay Satellite (EDRS). Phase-A study has just kicked off in January 2009. The targeted launch date is 2013. Heinrich Hertz will also use the SGEO platform. Heinrich Hertz is funded by the German Space Agency (DLR) and provides flight opportunities for technologies and components developed by the German Space Industry. With the HAG1 contract in hand, and EDRS and Heinrich Hertz in the line, OHB with its partners has the confidence that it will be able to speed up the product development of the SGEO platform for potential customers in the commercial market. This paper will first present the updated platform design and the status of the product development will be followed with the introduction of innovative payload technologies on board the first mission—HAG1 and ended with the mission concepts of EDRS and Heinrich Hertz missions.

Optical Intersatellite Communication

This paper describes the achievements in optical intersatellite communication based on technology developments that started in Europe (European Space Agency) more than 30 years ago. In 2001, the world-first optical intersatellite communication link was established (between the SPOT-4 and Advanced Relay and TEchnology MIssion Satellite (ARTEMIS) satellites), proving that optical communication technologies can be reliably mastered in space. In 2006, the Japanese Space Agency (JAXA) demonstrated a bidirectional optical link between its Optical Inter-Orbit Communications Engineering Test Satellite and ARTEMIS, and in 2008, the German Space Agency (DLR) established an intersatellite link between the near-field infrared experiment and TerraSAR-X satellites already based on the second generation of laser communication technology.

Development of the focal plane PNCCD camera system for the X-ray space telescope eROSITA

A so-called PNCCD, a special type of CCD, was developed twenty years ago as focal plane detector for the XMM-Newton X-ray astronomy mission of the European Space Agency ESA. Based on this detector concept and taking into account the experience of almost ten years of operation in space, a new X-ray CCD type was designed by the ‘MPI semiconductor laboratory’ for an upcoming X-ray space telescope, called eROSITA ( extended Roentgen survey with an imaging telescope array). This space telescope will be equipped with seven X-ray mirror systems of Wolter-I type and seven CCD cameras, placed in their foci. The instrumentation permits the exploration of the X-ray universe in the energy band from 0.3 up to 10 keV by spectroscopic measurements with a time resolution of 50 ms for a full image comprising 384×384 pixels. Main scientific goals are an all-sky survey and investigation of the mysterious ‘Dark Energy’. The eROSITA space telescope, which is developed under the responsibility of the ‘Max-Planck-Institute for extraterrestrial physics’, is a scientific payload on the new Russian satellite ‘Spectrum-Roentgen-Gamma’ (SRG). The mission is already approved by the responsible Russian and German space agencies. After launch in 2012 the destination of the satellite is Lagrange point L2. The planned observational program takes about seven years. We describe the design of the eROSITA camera system and present important test results achieved recently with the eROSITA prototype PNCCD detector. This includes a comparison of the eROSITA detector with the XMM-Newton detector.

New European Cinema: Redrawing the Map (review)

Reviewed by: New European Cinema: Redrawing the Map Irina Stakhanova New European Cinema: Redrawing the Map, Rosalind Galt . New York: Columbia University Press, 2006, 296 pp. New European Cinema: Redrawing the Map can be seen as a learned and judicious analysis of the impact of the disintegration of the national frontiers and the formation of the European Union and the national cinema in Germany, Italy, and former Yugoslavia. Operating within the realms of post-structuralist and postmodernist theories of Eurocentric cultural space, the book assesses dominant "master narratives" of new European cinema and addresses the shift from etic to emic (as linguists would call it), analyzing the connection between regional, national, and European history, popular memory, and spectacle. Galt's approach, in general, reflects the growing interest within the area of social and cultural studies in R. G. Collingwood's idea of history as a reenactment of past experience and the validity of personal memory as an accountable representation of the past. Referring to the ongoing discussion about national political and cultural identity, the author extends the views of spatial and temporal constituents of the cinematic image and visual narrative that represent popular memory into a persuasive discussion of genre, political and gendered landscape, cognitive and textual mapping, and themes of loss, nostalgia, and [End Page 63] melancholia in the modern European spectacle. Chapter 2 provides an insightful textual analysis of landscape as an ideological subject and extends the views of landscape as la belle image with a discussion of historic authenticity and genre of heritage films and melodrama, with takes on a phenomenon of Italian melodrama of the 1990s (Cinema Paradiso [1988], Mediterraneo [1991], and Il Postino [1994]). After discussing the politics of landscape and the notion of displacement with detail and comparisons, the author moves to analyze the role of hypercathexis and "libidinal attachment"(49) while describing the use of mourning and disengagement in creating the melodramatic effect. In addition, by applying the methodology of feminist film theory to deconstruct landscape spectacle as a fetish, the author makes a persuasive argument about the necessity of addressing the binary essence of image as spectacle (visibility and pleasure) and as narrative (historicity and ideology). What is almost inevitably more difficult, however, is connecting the postmodern notion of cognitive space and mapping to cinematic representation and drawing conclusions about cultural and subjective re-mapping and its textualization in new European cinema. By contravening the habitual focus on theories of politics of national space, the author successfully identifies the quest for the rhetoric of broader definition of post-Wall and post-Communist space and gives an eloquent description of the future films produced in Germany and former Yugoslavia. Chapters 4 and 5 keep a proper perspective on complexity of representation relative to the general motions of cinematic discourse in Europe and attempt to define the practices of cinematic identifications within history, territory, and the notion of "belonging" by providing the comprehensive overview of cinematic discourses, which are predetermined by symbiotic processes of national identification within the different post-Wall (Germany) and post-Communist contexts (former Yugoslavia). Acknowledging that reinterpretation of the past and reinvention of postwar historic narrative became a common theme in European cinema of the 1990s, Galt convincingly suggests that whereas berlin.killer.doc (1999) and Zentropa (1991) represent the transitional character of national memory and space in relation to otherness, Underground (1999) creates the notion of the "vicious circle" (174) and the impossibility of mapping the modern national space. Furthermore, the author makes a compelling case in identifying the difference between the broken marginality of the "dematerialized and denationalized"(193) cinematic German space in transition outward and the use of the nostalgic "doubled relation" inward gaze to the past presented in Balkan cinema. The final chapter summarizes the basic approaches to the theory of European space by incorporating Walter Benjamin's notion of aestheticization of politics and underlying the concept of constellation of discourses that "allows us to read history alongside the present" (231). The author stresses the importance of reevaluating traditions in film analysis to align them with newly emerging geopolitical realities, theories of spectacle, and practices of interpretation. She points out the necessity of expanding borders of...

A compact, light-weight high data-rate antenna system for remote-sensing orbiters and space exploration

Upcoming space missions utilizing hyperspectral or other high-resolution sensors will generate a vast amount of data in orbit. The average communication duration between a spacecraft in low Earth orbit (LEO) to a dedicated ground station is short and in addition, due to the high amount of data to be transferred at link times, a high-performance communication system on board of the satellite is indispensable. A solution that provides longer acquisition times with the ground station is to employ a high data-rate inter-satellite link to a geostationary relay satellite, which requires a flat, compact, steerable, light-weight yet robust antenna. Such an antenna system (antenna module plus pointing module) was developed for S-Band at the Institute of Astronautics (Technische Universität München), in cooperation with German space companies, research institutes and the German Aerospace Center (DLR). Its successful operation via the geostationary relay satellite Artemis was demonstrated in cooperation with ESA in 2007. This paper describes the evaluation of an antenna system in the Ka-Band, as a successor to be developed in the next two years for high data rates and the various applications of such an antenna system.

TerraSAR-X Precise Trajectory Estimation and Quality Assessment

Since the launch of TerraSAR-X on June 15, 2007, the required precise orbit products have been provided by the German Space Operations Center to support operational spaceborne synthetic aperture radar (SAR) and interferometric SAR image processing. The TerraSAR-X precise trajectory is reconstructed solely based on the Global Positioning System (GPS) measurements from a geodetic-grade dual-frequency Integrated Geodetic and Occultation Receiver (IGOR) onboard the spacecraft. The GPS-based precise orbit determination (POD) strategy used in the estimation of the precise TerraSAR-X orbit and its performance will be fully described in this paper. Five-month statistics from the internal and external orbit assessment indicate a root-mean-squared 3-D orbit accuracy of better than 10 and 20 cm for the precise science orbit and precise rapid orbit (PRO) products, respectively. The POD performance of the backup single-frequency MosaicGNSS receiver to support operational PRO product generation in case of IGOR tracking failure or interruptions is described as well.

Ceramic Microwave Circuits for Satellite Communication

KERAMIS is the acronym of a German research and development project funded by the German Space Agency (DLR) and the Federal Ministry of Economics and Technology (BMWI). The consortium is developing an RF circuit technology for Ka band multimedia satellite applications. A set of modules has been designed, manufactured, and tested by the partners of the consortium. The goal of this effort is to qualify the KERAMIS technology for space applications and to participate in an on-orbit-verification (OOV) program of the DLR. The launch of the technology verification satellite (TET) is scheduled for late 2010. This paper will give an overview of innovative circuit and module designs as well as the assembly, integration, and test results of the project. The authors will present a modular circuit concept for state-of-the-art transmitters and receivers in space at around 20 GHz. Selected modules are a 4 × 4 switch matrix, two synthesizers, and other RF modules. All circuits are based on multilayer ceramic (LTCC) including passive components, transitions, housings, and DC supply.

Points of Entanglement: The Overdetermination of German Space and Identity in <em>Lola + Bilidikid</em> and <em>Walk on Water</em>

Author(s): Baer, Nicholas | Abstract: In this essay, I consider how films have engaged with the politics of German space and identity in the context of the country’s National Socialist past – and, more specifically, in the context of relations between and among Germans, Jews, and Turks. I analyze scenes from two recent films, Turkish director Kutlug Ataman’s Lola + Bilidikid (1999) and Israeli director Eytan Fox’s Walk on Water (2004), that evoke Beruhrung between and among these groups through their use of spaces in Berlin that bear weighty historical and ideological connotations. Of key interest for me is the function of queerness and drag in these scenes, as well as the manner in which the scenes serve not only as contestations over space, but also as opportunities for the negotiation of the German body politic.

Calorie Restriction Modulates Inactivity-Induced Changes in the Inflammatory Markers C-Reactive Protein and Pentraxin-3

Energy balance and physical activity potentially influence systemic inflammation. Our objective was to test the hypothesis that moderate energy restriction may prevent activation of inactivity-induced inflammatory response. Participants were studied four times at the end of 14-d periods of experimental bed rest or controlled ambulation, after receiving eucaloric or hypocaloric diets. The study was conducted at the clinical research center of the German Space Agency. Nine healthy young volunteers participated. Energy intake was calibrated to physical activity and decreased by about 20% in hypocaloric conditions. Changes in body fat by dual-energy x-ray absorptiometry as well as plasma inflammatory markers and cytokine mRNA levels in blood cells were measured. Fat mass did not change significantly in eucaloric conditions and decreased in hypocaloric periods (-1.0 +/- 0.3 and -1.0 +/- 0.3 kg in ambulatory and bed rest, respectively). Bed rest in eucaloric conditions increased plasma C-reactive protein (CRP) (+143 +/- 53%) and both the ratios between plasma IL-6 and IL-10 (4+/-1 times) and white blood cell IL-6 and IL-10 mRNAs (5 +/- 1 times). Energy restriction prevented bed-rest-mediated increases in CRP and the IL-6 to IL-10 ratio. Bed rest increased (P = 0.03) long pentraxin-3 (PTX3) plasma concentration, without significant activity-by-diet interaction. In all conditions (n = 36), CRP and PTX3 were inversely correlated (r = -0.61; P < 0.001). Changes in fat mass, leptin, and IL-6 directly correlated with CRP and inversely correlated with PTX3. IL-10 inversely correlated with CRP and directly correlated with PTX3 (r = 0.52; P < 0.01). Calorie restriction prevents the inflammatory response induced by 14 d of bed rest. We suggest an inverse regulation of CRP and PTX3 in response to changes in energy balance.

The AMS-02 transition radiation detector

The Alpha Magnetic Spectrometer (AMS-02) experiment will be mounted on the International Space Station (ISS) for 3 years to perform precision cosmic particle spectroscopy in space. The search for dark matter candidates requires precise e + -spectroscopy in the energy range from 10 GeV up to 300 GeV. Therefore, the dominating p-background has to be reduced by a factor of 10 6 . This will be achieved with the AMS-02 electromagnetic calorimeter delivering 3–4 orders of magnitude and the transition radiation detector with proton rejection between 100 and 1000. The AMS-02 TRD consists of 20 layers of 6 mm diameter straw modules alternating with 20 mm layers of polyethylene/polypropylene fleece radiator. The straws are filled with a 80 % :20 % Xe / CO 2 gas mixture at 1.0 bar absolute from a recirculating gas system designed to operate > 3 years. The straw modules will be operated in proportional mode at a gas gain of 3000. For the readout a dedicated low-power data-acquisition system based on VA analog multiplexers has been developed. The completed construction and assembly of the detector is presented with special emphasis on space qualification, long flight duration aspects and calibration of the AMS-02 TRD. This project is funded by the German Space Agency DLR (contract 50OO0501), the US Department of Energy DOE and NASA.

Photon counting laser altimeter for planetary exploration—the technology demonstrator

The European space agency has nominated the laser altimeter as one of the principal devices for planetary research for the next decade. The device should be capable of ranging over distances of 400 - 1000 km and of acquiring information about the probe altitude above the planet surface and about the surface terrain profile with a precision of the order of 1 m. Recently, the technology demonstrator of the altimeter has been under development at the German Air and Space Agency, Institute of Planetary Research, Germany. The altimeter technology demonstrator is based on a diode pumped frequency doubled Nd: YAG laser delivering 50 mJ at 532 nm in 3 ns long pulses with the repetition rate of 20 kHz. The solid state echo signal detector in photon counting mode will be used. The optical part of the altimeter is scaled down to simulate the real background count rate scenario and to reduce the energy budget link by a factor of 104 at the same time. The demonstrator should be capable of ranging objects at distances of 0 - 5 km in both night and day time. We present the concept, design and construction of the timing system and detector part of the laser altimeter technology demonstrator, which has been developed at the Czech Technical University in Prague, optimized for the photon counting altimeter concept. The timing system has interval resolution 0.25 ns, stability and linearity similar to 0.1 ns, epoch resolution 100 mu s and accuracy 1 mu s, and a programmable range gate.

The EnMAP hyperspectral imager—An advanced optical payload for future applications in Earth observation programmes

The Environmental Mapping and Analysis Program (EnMAP) is a joint response of German space industry, Earth observation research institutions and value-adding (VA) resellers. EnMAP fulfills the increasing demand on accurate, quantitative information about the evolution of terrestrial ecosystems. The payload consists of an imaging hyperspectral instrument covering the visible, near- and short-wave infrared wavelengths. EnMAP will provide high quality, standardized, and consistent data on a timely and frequent basis. The mission's primary focus will be on the considerable improvement of already standardized products and the development of new quantitative and subsequently highly informative data and its derivatives. The advanced hyperspectral instrument on EnMAP can resolve and detect biophysical, biochemical, and geochemical variables in distinct detail. These data can only be derived from an EnMAP type instrument and will tremendously increase our understanding of coupled biospheric and geospheric processes and thus, enable the management and ensure the sustainability of our vital resources. The instrument data set allows for a detailed monitoring, characterization and parameter extraction of vegetation targets, rock/soils, and inland and coastal waters on a global scale.

Automated payload and instruments for astrobiology research developed and studied by German medium-sized space industry in cooperation with European academia

For more than a decade Kayser-Threde, a medium-sized enterprise of the German space industry, has been involved in astrobiology research in partnership with a variety of scientific institutes from all over Europe. Previous projects include exobiology research platforms in low Earth orbit on retrievable carriers and onboard the Space Station. More recently, exobiology payloads for in situ experimentation on Mars have been studied by Kayser-Threde under ESA contracts, specifically the ExoMars Pasteur Payload. These studies included work on a sample preparation and distribution systems for Martian rock/regolith samples, instrument concepts such as Raman spectroscopy and a Life Marker Chip, advanced microscope systems as well as robotic tools for astrobiology missions. The status of the funded technical studies and major results are presented. The reported industrial work was funded by ESA and the German Aerospace Center (DLR).

Gravitational biology within the German Space Program: goals, achievements, and perspectives

Gravity plays an important role for the evolution, orientation and development of organisms. Most of us, however, tend to overlook its importance because--due to its constant presence from the beginning of evolution some 4 billion years ago--this environmental parameter is almost hardwired into our interpretation of reality. This negligence of gravity is the more surprising as we all have our strong fights with this factor, especially during the very early and again during the late phases of our lives. On the other hand, scientists have been fascinated to observe the effects of gravity especially on plants and microorganisms for more than a hundred years, since Darwin and Sachs demonstrated the role of the root cap for downward growing plants. Different experimental approaches are nowadays available in order to change the influence of gravity and to study the corresponding influences on the physiology of biological systems. With the advent of spaceflight, a long-term nearly nullification of gravity is possible. Utilisation of this so-called "microgravity" condition for research in life sciences thus became an important asset in the space programs of various space agencies around the world. The German Space Life Sciences Program is managed--like all other space programs and activities in Germany--by the German Aerospace Center (DLR) in its role as space agency for Germany. Within the current space program, approved by the German government in May 2001, the overall goal for its life sciences part was defined as to gain scientific knowledge and to disclose new application potential by research under space conditions, especially by utilising the microgravity environment of the International Space Station. Three main scientific fields have been identified in collaboration with the scientific community: integrative human physiology, biotechnological applications of the microgravity environment, and fundamental biology of gravity and radiation responses (i.e., gravitational and radiation biology). In the present contribution, specific goals as well as achievements and perspectives of research in gravitational biology are given. In addition, some information is provided on spaceflight opportunities available.

From the Bremen Drop Tower to the international space station ISS – Ways to weightlessness in the German space life sciences program

AbstractInvestigations on the effects of gravity on living systems, especially the perception and transduction of this important environmental parameter, are in the focus of the German Space Life Sciences Program since several years. This program is managed – like all other space activities – by the German Aerospace Center DLR in its role as the German Space Agency. Funding of scientists, placing contracts to industry for the development of necessary space research facilities, and providing flight opportunities for performing space experiments including international coordination with other space agencies are the main responsibilities of the agency. In the present contribution the special features of the various flight opportunities, which are made available by DLR for life sciences research, are described in some detail. By this, scientists should become aware of the interesting possibilities to perform space research in the frame of the German Space Life Sciences Program, while other contributions in this special publications will focus on the results obtained, especially in the area of gravity signal transduction.

Analytical model for flow-excited interior cavity resonance and its application to the Stratospheric Observatory for Infrared Astronomy (SOFIA)

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint effort between NASA and the German Space Agency that has installed a 20&amp;lt;th&amp;gt;000-kg telescope in a modified 747-SP. The modifications entailed constructing bulkheads, one of which is used to provide the active mount for the telescope, and a door that rotates to open as much as one-quarter of the fuselage circumference to the atmosphere. This configuration represents a large compartment that can exhibit acoustic resonances at low frequencies. Concern arose that a Rossiter mode, which is an aerodynamic resonance in which vortices shed from the leading edge of a gap form a coherent standing pattern at certain speeds, would create a strong acoustic source for acoustic and structural modes, whose frequencies might coincide. A model consisting of a two-dimensional hard-walled waveguide having a Rossiter mode source and an elastic plate at one end was analyzed in order to understand these issues. Unlike conventional analyses of interior cabin noise, in which vibrating walls are the acoustic source, the elastic plate represents a compliant boundary that couples with the acoustic modes. The results lead to some general insights to the the possibility of a ‘‘triple resonance,’’ as well as the role of structural compliance for cavities that are excited by turbulent external flows.

Long-term/strategic scenario for reusable booster stages

This paper describes the final design status of a partially reusable space transportation system which has been under study for five years within the German future launcher technology research program ASTRA. It consists of dual booster stages, which are attached to an advanced expendable core. The design of the reference liquid fly-back boosters (LFBB) is focused on LOX/LH2 propellant and a future advanced gas-generator cycle rocket motor. The preliminary design study was performed in close cooperation between DLR and the German space industry. The paper's first part describes recent progress in the design of this reusable booster stage. The second part of the paper assesses a long-term, strategic scenario of the reusable stage's operation. The general idea is the gradual evolution of the above mentioned basic fly-back booster vehicle into three space transportation systems performing different tasks: Reusable First Stage for a small launcher application, successive development to a fully reusable TSTO, and booster for a super-heavy-lift rocket to support an ambitious space flight program like manned Mars missions. The assessment addresses questions of technical sanity, preliminary sizing and performance issues and, where applicable, examines alternative options.