The International X-ray Observatory IXO, a candidate follow-on mission for XMM/Newton and CHANDRA, has been studied in Europe in the frame of two parallel industrial assessment studies commissioned by ESA as part of the Cosmic Vision 2015-2025 programme. One of these studies was successfully carried out by EADS Astrium. The present paper is focussed on the results obtained by Astrium GmbH in this study, i.e. on the optical, mechanical and thermal design of the IXO telescope mirror and on the predicted telescope performance.
The IXO telescope mirror consists of nearly 1700 Silicon Pore Optics (SPO) mirror modules  accommodated on eight identical petal-shaped support structures. These petals are themselves supported by an optical bench. Design drivers proved to be the allowable mass, the required optical throughput as well as the axial and lateral stiffness required by the launch vehicle. To ensure light-weighting, low thermal gradients as well as robustness during AIV, the petals and the optical bench are deliberately made of a high-modulus carbon fibre material with high thermal conductivity. The telescope optical performance achievable with this design has been analysed based on rigorous finite element, thermal and optical modelling. It has been found to be fully compliant with the required optical throughput and image quality, thus enabling the scientific benefit of the IXO mission.
The XEUS mission is conceived as Europe's next generation X-ray space observatory aiming at the detection and
spectroscopy of faint astronomical sources located at high red-shift. With unprecedented sensitivity to the million-degree
hot universe, XEUS is supposed to explore key areas of contemporary astrophysics. Due to the considerable telescope
focal length of 35 m, the mission profile foresees two separate spacecraft, one carrying the mirrors, the other one
carrying the detectors, flying in precise formation as if connected by a rigid telescope tube. The paper presents an
innovative light-weight X-ray telescope design and its predicted performance as resulting from a recent study on XEUS
Telescope Accommodation funded by the European Space Agency ESA. The main challenge of this work was to find a
telescope concept compatible with the Ariane V launcher constraints while meeting highly demanding optical
Within the scope of the DARWIN Technology and Research Programme, the European Space Agency (ESA) initiated the development of a dynamic system simulator (called FINCH "Fast Interferometer Characterization") for the spaceborne nulling interferometry mission DARWIN.The FINCH project is realized by two parallel activities:
(1) a simulator for the Guidance, Navigation and Control (FINCH/GNC) of the free-flying satellite array, and (2) a simulator for the optical subsystems and the beam propagation within the system (FINCH/OPT). While the GNC activity is handled by EADS Astrium, France, the optical part is performed in a joint effort by EADS Astrium, Germany, and the European Southern Observatory (ESO).
In this paper we focus on FINCH/OPT aspects and describe:
• DARWIN and the corresponding overall end-to-end simulation approach
• the completed FINCH/OPT development for modelling of point sources
• modelling of extended objects, exact and with suitable approximations
• details of optical modelling of DARWIN configurations within FINCH
• applications of FINCH
This article presents a software package for “integrated modeling” of single- and multi-aperture optical telescopes. Integrated modeling is aiming at time-dependent system analysis combining different technical disciplines such as optics, mechanical structure, control system with sensors and actuators. Various, environmental and internal disturbances can be taken into account. Software design and development is done in a joint effort by the European Southern Observatory (ESO), Astrium GmbH and the Institute of Lightweight Structures (LLB), Technical University of Munich. The architectures of the two most advanced modules generating dynamic models of the mechanical structure and the optical system are described. A “real-life” example related to the Very Large Telescope Interferometer (VLTI) illustrates the application in practice.
As part of an “Integrated Modeling Toolbox” described in Wilhelm, Koehler et al. 2002 (these proceedings) the optical modeling tool BeamWarrior has been developed. Its main purpose is the creation of optical models for integration into a dynamic control system simulation. Offering a versatile set of geometrical and wave optical propagation algorithms it can also be used for sophisticated static optical analysis. The article summarizes the functional features of the tool and describes its algorithms - both, from a theoretical and practical point of view.
The OISI Dynamic end-to-end modeling tool is tailored to end-to-end modeling and dynamic simulation of Earth- and space-based actively controlled optical instruments such as e.g. optical stellar interferometers. `End-to-end modeling' is meant to denote the feature that the overall model comprises besides optical sub-models also structural, sensor, actuator, controller and disturbance sub-models influencing the optical transmission, so that the system- level instrument performance due to disturbances and active optics can be simulated. This tool has been developed to support performance analysis and prediction as well as control loop design and fine-tuning for OISI, Germany's preparatory program for optical/infrared spaceborne interferometry initiated in 1994 by Dornier Satellitensysteme GmbH in Friedrichshafen.