Design of a canard configured TransCruiser using CEASIOM

CEASIOM is a multidisciplinary software environment for aircraft design that has been developed as part of the European Framework 6 SimSAC project. It closely integrates discipline-specific tools such as those used for CAD, grid generation, CFD, stability analysis and control system design. The environment allows the user to take an initial design from geometry definition and aerodynamics generation through to full six degrees of freedom simulation and analysis. Key capabilities include variable fidelity aerodynamics tools and aeroelasticity modules. The purpose of this paper is to demonstrate the potential of CEASIOM by presenting the results of a Design, Simulate and Evaluate (DSE) exercise applied to a novel, project specific, transonic cruiser configuration called the TCR. The baseline TCR configuration is first defined using conventional methods, which is then refined and improved within the CEASIOM software environment. A wind tunnel model of this final configuration was then constructed, tested and used to verify the results generated using CEASIOM.     

A model of the effects of heavy ion radiation on human tissue

In heavy ion radiotherapy and space travel humans are exposed to energetic heavy ions (C, Si, Fe and others). This type of irradiation often produces more severe biological effects per unit dose than more common X-rays. A new Monte Carlo model generates a physical space with the complex geometry of human tissue or a cell culture based model of tissue, which is affected by the passage of ionizing radiation. For irradiation, the model relies on a physical code for the ion track structure; for tissues, cellular maps are derived from two- or three-dimensional confocal microscopy images using image segmentation algorithm, which defines cells as pixilated volumes. The model is used to study tissue-specific statistics of direct ion hits and the remote ion action on cells. As an application of the technique, we considered the spatial pattern of apoptotic cells after heavy ion irradiation. The pattern of apoptosis is modeled as a stochastic process, which is defined by the action cross section taken from available experimental data. To characterize the degree of apoptosis, an autocorrelation function that describes the spatial correlation of apoptotic cells is introduced. The values of the autocorrelation function demonstrate the effect of the directionality of the radiation track on the spatial arrangements of inactivated cells in tissue. This effect is intrinsic only to high linear-energy-transfer radiation.     

Assessing the elemental composition of comet 81P/Wild 2 by analyzing dust collected by Stardust

One of the prime objectives in the analysis of cometary dust collected by the Stardust space mission is to determine the elemental composition of comet 81P/Wild 2. For this analysis, samples captured by two sampling media, silica aerogel and Al foil, were available. While aerogel was qualified to sample the dust almost intact, particles impinging on Al foils produced hypervelocity impact craters with residual cometary matter. Both sample types delivered valuable information on the cometary inventory, even though a slight loss of volatiles was observed for impact residues on Al foils. Altogether an elemental composition close to solar elemental abundances was observed, indicating that the early solar system was chemically rather homogeneous from the innermost regions close to the sun to the outer edge of the solar system, the presumed region of cometary origin.     

Characterizing high-energy-density propellants for space propulsion applications

A technique for computationally determining the thermophysical properties of high-energy-density matter (HEDM) propellants is presented. HEDM compounds are of interest in the liquid rocket engine industry due to their high density and high energy content relative to existing industry-standard propellants. In order to accurately model rocket engine performance, cost and weight in a conceptual design environment, several thermodynamic and physical properties are required over a range of temperatures and pressures. The approach presented here combines quantum mechanical and molecular dynamic (MD) calculations and group additivity methods. A method for improving the force field model coefficients used in the MD is included. This approach is used to determine thermophysical properties for two HEDM compounds of interest: quadricyclane and 2-azido-N,N-dimethylethanamine (DMAZ). The modified force field approach provides results that more accurately match experimental data than the unmodified approach. Launch vehicle and Lunar lander case studies are presented to quantify the system level impact of employing quadricyclane and DMAZ rather than industry standard propellants. In both cases, the use of HEDM propellants provides reductions in vehicle mass compared to industry standard propellants. The results demonstrate that HEDM propellants can be an attractive technology for future launch vehicle and Lunar lander applications.     

Communicating across the solar system

The technological advances of the Space Age have enabled us to project our senses through complex instruments to the edge of the Solar System and beyond. The link back to Earth by the communication channel has provided us with a wealth of information. The vast improvement in communication capability, by a factor of 10¹⁸, from the launching of the first earth satellites to the capacity of the Voyager telecommunications link across the Solar System, is symbolic of both our technical prowess and our cultural development. The combination of data rate and extreme distance at the Voyager 2 encounters with Uranus and Neptune in 1986 and 1989 will require the ground network to perform an engineering feat of unequalled magnitude. This paper describes the engineering challenge of communicating with spacecraft at the limits of the Solar System and the engineering responses to that challenge.     

Office Information Systems Cost Justification

The purpose of this paper is to present a new methodology for the cost justification of office information systems in engineering environments [1]. The methodology is called the hedonic wage model. It is based on the fact that the allocation of labor resources in an organization tends to conform to certain logical economic criteria. These criteria, along with information on the costs of labor and on how workers spend their time, permit inferences about the organizational values of key activities. The value of an information system can be estimated based on its contribution to the key activities.     

Satelliten-scatterometer zur windmessung

(A spaceborne scatterometer for wind field measurement)—For correct weather forecasting over the continent, the knowledge of the weather conditions across the oceans is of importance. The Skylab S-193 experiment, as well as Seasat, have shown that global wind measurements across the ocean with the aid of a microwave sensor is technically feasible. For this reason, a Wind Scatterometer will be implemented among other instruments on the first European Remote Sensing Satellite, ERS-1.In this presentation, the geophysical background of the measurement principle is briefly explained. A short discussion about the method of extraction of wind speed and wind direction out of Scatterometer measurement data follows. Finally, different sensor concepts are presented and a comparison of real and computed wind fields over the Atlantic closes the presentation about the Wind Scatterometer.Software simulators are necessary for the development and optimization of the Scatterometer system design. Such software simulators are under development at Dornier System, which holds technical responsibility for the Scatterometer. A short overview of this work is also given.     

The origin of cosmic rays

In the following we describe recent progress in our understanding of the origin of cosmic rays. We propose that cosmic rays originate mainly in three sites, a) normal supernova explosions into the interstellar medium, b) supernova explosions into stellar winds, and c) hot spots of powerful radio galaxies. The proposal depends on an assumption about the scaling of the turbulent diffusive transport in cosmic ray mediated shock regions; the proposal also uses a specific model for the interstellar transport of cosmic rays. The model has been investigated in some detail and compared to i) the radio data of OB stars, Wolf Rayet stars, radio supernovae, radio supernova remnants, Gamma-ray line and continuum emission from starforming regions, and the cosmic ray electron spectrum, ii) the Akeno air shower data over the particle energy range from 10 TeV to EeV, and iii) the Akeno and Fly's Eye air shower data from 0.1 EeV to above 100 EeV.     

Meteors do not break exogenous organic molecules into high yields of diatomics

Meteoroids that dominate the Earth's extraterrestrial mass influx (50-300 microm size range) may have contributed a unique blend of exogenous organic molecules at the time of the origin of life. Such meteoroids are so large that most of their mass is ablated in the Earth's atmosphere. In the process, organic molecules are decomposed and chemically altered to molecules differently from those delivered to the Earth's surface by smaller (<50 microm) micrometeorites and larger (>10 cm) meteorites. The question addressed here is whether the organic matter in these meteoroids is fully decomposed into atoms or diatomic compounds during ablation. If not, then the ablation products made available for prebiotic organic chemistry, and perhaps early biology, might have retained some memory of their astrophysical nature. To test this hypothesis we searched for CN emission in meteor spectra in an airborne experiment during the 2001 Leonid meteor storm. We found that the meteor's light-emitting air plasma, which included products of meteor ablation, contained less than 1 CN molecule for every 30 meteoric iron atoms. This contrasts sharply with the nitrogen/iron ratio of 1:1.2 in the solid matter of comet 1P/Halley. Unless the nitrogen content or the abundance of complex organic matter in the Leonid parent body, comet 55P/Tempel-Tuttle, differs from that in comet 1P/Halley, it appears that very little of that organic nitrogen decomposes into CN molecules during meteor ablation in the rarefied flow conditions that characterize the atmospheric entry of meteoroids approximately 50 microm-10 cm in size. We propose that the organics of such meteoroids survive instead as larger compounds.     

Committee on the peaceful uses of outer space

The first artificial earth satellite, Sputnik 1, was launched on 14 October 1957 and proceeded to orbit the Earth blithely unconcerned with the political boundaries below. It was apparent that space activities had international implications. In the United Nations, the question of space activities was first raised in 1957 in the context of the debate on disarmament. In 1958, the ‘Question on the Peaceful Uses of Outer Space’ was placed on the agenda of the General Assembly, which adopted a resolution establishing an Ad Hoc Committee on the Peaceful Uses of Outer Space (COPUOS).