Studying the evolution of the hot universe with the X-ray evolving universe spectroscopy mission – XEUS

Europe is one of the major partners building the International Space Station (ISS) and European industry, together with ESA, is responsible for many station components including the Columbus Orbital Facility, the Automated Transport Vehicle, two connecting modules and the European Robotic Arm. Together with this impressive list of contributions there is a strong desire within the ESA Member States to benefit from this investment by utilizing the unique capabilities of the ISS to perform world-class science. XEUS is one of the astronomical applications being studied by ESA to utilize the capabilities of the ISS. XEUS will be a long-term X-ray observatory with an initial mirror area of 6 m² at 1 keV that will be expanded to 30 m² following a visit to the ISS. The 1 keV spatial resolution is expected to be 2–5″ half-energy-width. XEUS will consist of separate detector and mirror spacecraft (MSC) aligned by active control to provide a focal length of 50 m. A new detector spacecraft, complete with the next generation of instruments, will also be added after visiting the ISS. The limiting 0.1–2.5 keV sensitivity will then be 4 × 10⁻¹⁸ erg cm⁻² s⁻¹, around 200 times better than XMM-Newton, allowing XEUS to study the properties of the hot baryons and dark matter at high redshift.     

Supplements to Active Filters in the VOR

This paper covers some important advances in understanding the problems associated with the VOR system, especially in connection with area navigation. Anomalies arising from airborne equipment, operating in the airborne environment, are described and analyzed. Factors contributing to overall system accuracy are treated with respect to VOR receiver response and to rate-limiting, filter means, with special attention to appropriate noise reduction systems providing zero or minimal time delay characteristics. The use of active filters in the VOR receiver is shown to be of major importance with regard to signal improvement and overall system accuracy. Active filters of the constant slew rate type have proved of significant value, both within the VOR receiver as well as in signal processing.     

Results of the parabolic flight tests of the rapunzel deployer

The tether assisted re-entry of small payloads is a highly interesting tool for space transportation especially for the return of small payloads from Space Station ISSA. The small tether mission Rapunzel was initiated in 1991 by the Institute of Astronautics, TU München and the Kayser-Threde Company, to design a low cost and feasible tether experiment for the verification of the tether assisted re-entry. Together with the Samara State Aerospace University, Russia, a mission concept on a Russian Resurs or Photon capsule was developed. Based on this mission a deployer has been designed, mainly based on technology of the textile industry, which insures high reliability at low cost. Recently a similar configuration is being discussed for the ESA-TSE mission.The main work during the recent time was the development and test of the breadboard model of the deployer system. After successfully completing initial ground tests with the deployer, further tests during the ESA Parabolic Flight campaign in November 1995 were conducted. After a short introduction of the overall mission scenario, the planned configuration in orbit, this paper will present the results of the microgravity test campaign onboard the KC-135 aircraft and compare them with the ground test. The deployer showed a good performance during all tests, including ejection of the end-mass, deployment, and braking. Problems that occurred during the tests will be discussed, and solutions for the detected flaws and the results of the redesign now in progress will be presented. These verifications have shown the feasibility of the concept and will lay the base for the planned development of the flight model of the deployer.     

Enhanced operations efficiency by using the unified synoptic system

The unified synoptic system (USS) was developed by ESA for replacing the existing Columbus display solutions and to unify the display system used on-board and on-ground. USS provides enhanced flight operations efficiency and reduced effort for product preparation, qualification and maintenance for synoptic displays. Additional to its use for Columbus it is installed at JAXA and NASA to support requirements definition and review of NASA generated ISS displays. Due to its advanced capabilities, which go beyond existing known solutions, it has been made available to be reused for future spacecraft EGSEs and control centres (e.g. exploration missions, satellites) as well. Use of synoptic display is mostly guided by operational procedures which are in electronic format. However, till now the full operational benefit has not yet been realized. Procedure viewers and synoptic display systems are completely separate entities. Direct interaction of procedure viewers with synoptic display systems or underlying system control software is not supported at all. Therefore astronauts, flight controllers and operators still have to carry out a lot of mundane activities when executing operational procedures. The USS based procedural display viewer provides the user with a coherent, task oriented user interface for using synoptic displays and executing procedures in an efficient manner.     

The Influence of Geometrical and Nongeometrical Features on the Use of the Lexical Concepts NEAR and FAR in English and Finnish

Abstract

This paper investigates the impact of geometrical and nongeometrical features on the use of the lexical concepts NEAR and FAR in English and Finnish. Participants' acceptability ratings for these concepts demonstrate that a bar in between a Figure and a Ground acts as a scale-setting object but not as a distance enhancing barrier, shows that the influence of the geometrical feature Figure–Ground distance exceeds the influence of several nongeometrical features, but most of all reveals that language specific lexical properties associated with NEAR and FAR predict language dependent effects for functional relatedness in interaction with Figure–Ground distance and bar presence.