Gaia: focus, straylight and basic angle

conference paper
2016
Mora, A.

Biermann, M.

Bombrun, A.

Boyadjian, J.

Chassat, F.

Corberand, P.

Davidson, M.

Doyle, D.

Escolar, D.

Gielesen, W.L.M.

Guilpain, T.

Hernandez, J.

Kirschner, V.

Klioner, S.A.

Koeck, C.

Laine, B.

Lindegren, L.

Serpell, E.

Tatry, P.

Thoral, P.
The Gaia all-sky astrometric survey is challenged by several issues affecting the spacecraft stability. Amongst them, we find the focus evolution, straylight and basic angle variations Contrary to pre-launch expectations, the image quality is continuously evolving, during commissioning and the nominal mission. Payload decontaminations and wavefront sensor assisted refocuses have been carried out to recover optimum performance. An ESA-Airbus DS working group analysed the straylight and basic angle issues and worked on a detailed root cause analysis. In parallel, the Gaia scientists have also analysed the data, most notably comparing the BAM signal to global astrometric solutions, with remarkable agreement. In this contribution, a status review of these issues will be provided, with emphasis on the mitigation schemes and the lessons learned for future space missions where extreme stability is a key requirement.
Topics
AstrometryBasic angleFocusGaiaInterferometryStabilityStraylightWavefront sensorAdaptive opticsConvergence of numerical methodsFocusingInterferometrySpace flightSpace telescopesMitigation schemesOptimum performanceRoot cause analysisWave front sensorsWorking groupsMillimeter waves
TNO Identifier
573284
Repository link
https://resolver.tno.nl/uuid:d938b9ee-06aa-4711-a396-dc1ec8d8f030
ISSN
0277786X
ISBN
9781510601871
Publisher
SPIE
Article nr.
99042D
Source title
Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, 26 June 2016 - 1 July 2016
Editor(s)
MacEwen, H.A.
Lystrup, M.
Fazio, G.G.
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