I am a scientist who is working for the Gaia satellite project of the European Space Agency (ESA). The main task of the satellite will be to derive a very precise map for about a billion stars in 3D. If you want to know more details about it please visit

In this blog I will report about my personal involvement in this project and I will summarize the official news about the Gaia project. The satellite has just past the Flight Acceptance Review – this means it is technically ready to be launched. The launch is currently foreseen for the second half of November 2013. But many things will need to happen before …

My main working topics are the characterization of the CCDs (saturation, non-linearities, sensitivity variations, … ), photometric calibration models and photometric standard star selection. I will contribute to the scientific validation of the different Gaia catalogues. During the commissioning phase I will be member of the Payload Expert Team helping to verify that the Gaia instrument will allow to meet the scientific requirements.


7 thoughts on “Introduction

  1. Pingback: #GAIA : les prochaines étapes à venir en campagne de tir | Rêves d'Espace

  2. Re: “Launch Fever Anyone?”
    Yes, I am obsessively seeking out any information I can find about GAIA’s progress toward launch. Your blog and the “official” have given me a much better appreciation for the attention to detail needed for a successful mission. I am an amateur astronomer obsessed with the “citizen science” of occultation timing ( ), and GAIA promises to completely revolutionize our event prediction accuracy, as Hipparcos did before. It will be hard to wait several more years for the compiled astrometry and ephemeris data releases!! Best of luck! -Ted

  3. This is a wonderful day: GAIA is on her way to L2 after a successful launch into orbit! Congratulations to all involved! I’ve heard the next stressful time comes tomorrow (20 Dec), when there is an orbit adjustment. One question I have is this: Now that the Fregat thruster has separated, where is GAIA getting its thrust for the L2 orbit insertion? I’m presuming there are small thrusters provided by the Service Module, but that hasn’t received much coverage or description. Holger, will your initial data evaluation begin soon? -Ted

    • Thank you, Ted! Sorry for my late reply. I was following the launch from the control center at ESOC, Darmstadt, Germany. In the hotel there the internet connection was very poor, even the pay option did not work. I had no access to these websites. Twitter was working sometimes. Stoneedge in Germany it seems to be, or at least in this hotel I was staying. But I am back now and will continue to post. To your questions: Yes, Gaia has its own propulsion system. Actually, it has two systems. The Chemical Propulsion System (CPS) is used for the main maneuvers as the “Day 2 maneuver” yesterday. And then there is a Micro Propulsion System (MPS) for controlling the spinning of the spacecraft during the observations. By the way, the “Day 2 maneuver” was very successful and needed to be shorter than planned as the Soyuz launcher had put Gaia on a very perfect orbit! A lot of fuel was saved enough for one more year operations in the orbit around L2!
      The initial science data will arrive in early January. We will have a look or two for sure. The initial tests will be performed by Astrium, the company that has build this wonderful spacecraft. They will check that everything is OK. Later on our organization DPAC will take over the leadership of the commissioning. My main tasks are planned for middle of April at the moment. I will keep you updated.
      Many thanks for your interest

  4. Holger,
    You all must be very busy: neither this web site nor have had any news since early March. I hope “no news is good news”, but it is natural to worry when the last news we had was that there is an undiagnosed light leak. When you have a spare moment, we would all like to know more about what has happened in March.

    • Hi Ted,
      No need to worry about at the moment. We are just very busy continuing to explore the stray light issue trying to improve the situation. We have made good progress on this very complex issue but the process is taking longer than we were hoping for. It may take another while until ESA will publish something about the situation. Sorry for not being able to say more at the moment – I have to follow the rules.

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