E. Serpell

TL;DR: The Gaia payload ensures maximum passive stability using a single material, SiC, for most of its elements, but dedicated metrology instruments are required to carry out two functions: monitoring the basic angle and refocusing the telescope.

TL;DR: In this article, a status review of these issues is provided, with emphasis on the mitigation schemes and the lessons learned for future space missions where extreme stability is a key requirement, and an ESA-Airbus DS working group was established during the early nominal mission and worked on a detailed root cause analysis.

TL;DR: In this paper, two interferometers fed by the same laser are used to measure the basic angle changes at the level of μas (prad, micropixel), which is the highest level ever achieved in space.

TL;DR: A status review of issues affecting the Gaia all-sky astrometric survey will be provided, with emphasis on the mitigation schemes and the lessons learned for future space missions where extreme stability is a key requirement.

TL;DR: The ESA Gaia mission uses two telescopes to create the most ambitious survey of the Galaxy. as discussed by the authors presents a summary of the in-orbit performance and some early results of the Basic Angle Monitoring system.