Objectives
TALC has an outer diameter of 20 m. The annular mirror has a width of 3 m. It will be deployed by a telescopic central mast. The surface of the telescope shall be passively cooled, protected by a sunshield like the one used by the James Webb Space Telescope (JWST). With this sunshield, the temperature shall be kept between 50K and 80K when placed at the Lagrange point L2.
Technology
The telescope consists of 24 stacked mirror segments which, in the deployed state, build a ring with a width of 3 m. The structure is similar to a big ferry wheel. The central mast carries the sensor and two bundles of ropes which shall hold the mirror segments in a precise position.
This invention revives the concept of tensegrity which is based on a rigid structure obtained by members that are exposed to tension and compression only but not to bending moments. The structure will incorporate active and adaptive optics in order to achieve low wavefront errors.
Literature
G. Durand, M. Sauvage, V. Révéré, P. Chanial, S. Ronayette, L. Scola, M. Carty, M. Durand, L. Durand, M. Berthe, S. Correi, P. Bultel: TALC, A 20m Thin Aperture Light Collector for infra red observations in space, Proceedings of the 2nd International Conference Advanced Lightweight Structures and Reflector Antennas, 1 - 3 October 2014, Tbilisi, Georgia (2014)
M. Sauvage, J. Amiaux, J. Austin, M. Bello, G. Bianucci, S. Chesné, O. Citterio, C. Collette, S. Correia, G. A. Durand, S. Molinari, G. Pareschi, Y. Penfornis, G. Sironi, G. Valsecchi, S. Verpoort, U. Wittrock: A development roadmap for critical technologies needed for TALC: a deployable 20m annular space telescope, Proc. SPIE 9904, 99041L (2016)
G. Durand, J. Amiaux, M. Sauvage, J. Austin, S. Chesne, C. Collette, S. Helgouashl, J. Pareschi, Y. Penfornis, G. Valsecchi, U. Wittrock: TALC a far-infrared 20m space telescope and the ELICSIR consortium to reach TRL 3, 37th ESA Antenna Workshop: Workshop on Large Deployable Antennas, 15 - 17 November 2016, ESTEC, Noordwijk, Netherlands (2016)
G. Durand, P. Daniel-Thomas, M. Sauvage, J. Amiaux, S. Chesne, C. Collette: The Teraherz 20m space telescope TALC, progress report on the deployment of the 20m wheel structure, Proceedings of the 3rd International Conference Advanced Lightweight Structures and Reflector Antennas, 19 - 21 September 2018, Tbilisi, Georgia (2018)