Malbet, FabienFabienMalbetLéger, AlainAlainLégerAnglada Escudé, GuillemGuillemAnglada EscudéSOZZETTI, AlessandroAlessandroSOZZETTISpolyar, DouglasDouglasSpolyarLabadie, LucasLucasLabadieShao, MikeMikeShaoHoll, BerryBerryHollGoullioud, RenaudRenaudGoullioudCrouzier, AntoineAntoineCrouzierBoehm, CélineCélineBoehmKrone-Martins, AlbertoAlbertoKrone-Martins2020-06-252020-06-25201697815106018710277-786Xhttp://hdl.handle.net/20.500.12386/26208Theia is a logical successor to Gaia, as a focused, very high precision astrometry mission which addresses two key science objectives of the ESA Cosmic Vision program: the nature of dark matter and the search for habitable planets. Theia addresses a number of other science cases strongly synergistic with ongoing/planned missions, such as the nature of compact objects, motions of stars in young stellar clusters, follow-up of Gaia objects of interest. Theia s "point and stare" operational mode will enable us to answer some of the most profound questions that the results of the Gaias survey will ask. Extremely-high-precision astrometry at 1-μas level can only be reached from space. The Theia spacecraft, which will carry a 0.8-m telescope, is foreseen to operate at L2 for 3,5 years. The preliminary Theia mission assessment allowed us to identify a safe and robust mission architecture that demonstrates the mission feasibility within the Soyuz ST launch envelope and a small M-class mission cost cap. We present here these features of the mission that has been submitted to the last ESA M4 call in January 2015.STAMPAenConference paper10.1117/12.22344252-s2.0-84991336320000385794100070https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9904/1/Microarcsecond-astrometric-observatory-Theia--from-dark-matter-to-compact/10.1117/12.2234425.short?SSO=12016SPIE.9904E..2FMFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering