TY - JOUR A1 - Rausch, Peter A1 - Verpoort, Sven A1 - Wittrock, Ulrich T1 - Unimorph deformable mirror for space telescopes: environmental testing JF - Opt. Expr. N2 - We have developed and manufactured a unimorph deformable mirror for space telescopes based on piezoelectric actuation. The mirror features 44 actuators, has an aperture of 50 mm, and is designed to reproduce low-order Zernike modes with a stroke of several tens of µm. We assessed the space compliance by operating the mirror in thermal vacuum, and exposing it to random and sinusoidal vibrations, as well as to ionizing irradiation. Additionally, the operational life time and the laser power handling capability were tested. The mirror was successfully operated in thermal vacuum at 100 K. We report on the conducted tests and the methods used to evaluate the mirror´s performance, and discuss the compliance with the demanded requirements KW - active or adaptive optics KW - telescopes thermal effects vibration analysis KW - radiation KW - space optics KW - space instrumentation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8530 VL - 24 SP - 1528 EP - 1542 ER - TY - CHAP A1 - Rausch, Peter A1 - Verpoort, Sven A1 - Wittrock, Ulrich T1 - Unimorph piezoelectric deformable mirrors for space telescopes T2 - Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, Proc. SPIE N2 - We have developed, manufactured and tested a unimorph deformable mirror for space applications based on piezoelectric actuation. The mirror was designed for the correction of low-order Zernike modes with a stroke of several tens of micrometers over a clear aperture of 50 mm. It was successfully tested in thermal vacuum, underwent lifetime tests, and was exposed to random vibrations, sinusoidal vibrations, and to ionizing radiation. We report on design considerations, manufacturing of the mirror, and present the test results. Furthermore, we discuss critical design parameters, and how our mirror could be adapted to serve recently proposed space telescopes such as HDST and TALC. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-9230 VL - 9904 SP - 990468 ER - TY - CHAP A1 - Sauvage, Marc A1 - Amiaux, Jérome A1 - Austin, James A1 - Bello, Mara A1 - Bianucci, Giovanni A1 - Chesné, Simon A1 - Citterio, Oberto A1 - Collette, Christophe A1 - Correia, Sébastien A1 - Durand, Gilles A. A1 - Molinari, Sergio A1 - Pareschi, Giovanni A1 - Penfornis, Yann A1 - Sironi, Giorgia A1 - Valsecchi, Guiseppe A1 - Verpoort, Sven A1 - Wittrock, Ulrich T1 - A development roadmap for critical technologies needed for TALC: a deployable 20m annular space telescope T2 - Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, Proc. SPIE N2 - Astronomy is driven by the quest for higher sensitivity and improved angular resolution in order to detect fainter or smaller objects. The far-infrared to submillimeter domain is a unique probe of the cold and obscured Universe, harboring for instance the precious signatures of key elements such as water. Space observations are mandatory given the blocking effect of our atmosphere. However the methods we have relied on so far to develop increasingly larger telescopes are now reaching a hard limit, with the JWST illustrating this in more than one way (e.g. it will be launched by one of the most powerful rocket, it requires the largest existing facility on Earth to be qualified). With the Thinned Aperture Light Collector (TALC) project, a concept of a deployable 20 m annular telescope, we propose to break out of this deadlock by developing novel technologies for space telescopes, which are disruptive in three aspects: • An innovative deployable mirror whose topology, based on stacking rather than folding, leads to an optimum ratio of collecting area over volume, and creates a telescope with an eight times larger collecting area and three times higher angular resolution compared to JWST from the same pre-deployed volume; • An ultra-light weight segmented primary mirror, based on electrodeposited Nickel, Composite and Honeycomb stacks, built with a replica process to control costs and mitigate the industrial risks; • An active optics control layer based on piezo-electric layers incorporated into the mirror rear shell allowing control of the shape by internal stress rather than by reaction on a structure. We present in this paper the roadmap we have built to bring these three disruptive technologies to technology readiness level 3. We will achieve this goal through design and realization of representative elements: segments of mirrors for optical quality verification, active optics implemented on representative mirror stacks to characterize the shape correction capabilities, and mechanical models for validation of the deployment concept. Accompanying these developments, a strong system activity will ensure that the ultimate goal of having an integrated system can be met, especially in terms of (a) scalability toward a larger structure, and (b) verification philosophy. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-9248 VL - 9904 SP - 99041L ER - TY - CHAP A1 - Durand, G. A1 - Amiaux, J. A1 - Sauvage, M. A1 - Austin, J. A1 - Chesne, S. A1 - Collette, C. A1 - Helgouashl, S. A1 - Pareschi, J. A1 - Penfornis, Y. A1 - Valsecchi, G. A1 - Wittrock, U. T1 - TALC a far-infrared 20m space telescope and the ELICSIR consortium to reach TRL 3 T2 - Proceedings of the 37th ESA Antenna Workshop, Noordwijk, Netherlands N2 - Further space exploration in the far-infrared (FIR) requires larger apertures in order to improve the spatial resolution of captured images. To this purpose, the Thinned Aperture Light Collector (TALC) concept of a deployable annular telescope has been recently developed at CEA, which offers novel perspectives for FIR space missions. The consortium ELICSIR consortium of European institutes and companies has been created to improve the technological readiness level (TRL) of its key systems and components. Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-9253 UR - http://esaconferencebureau.com/2016-events/16c18/introduction ER -