A full-size working model of Gaia’s internal systems arrived in Germany this week. The Avionics Model is mounted in a circular set-up representing the systems on the actual satellite, now orbiting the Sun–Earth L2 point about 1 500 000 km from Earth.

With the model at ESA’s European Space Operations Centre, ESOC, in Darmstadt, Germany, the ESA flight control specialists responsible for Gaia now have access to a fully functional test bench of the inner workings of the billion-star surveyor.

The model will remain at ESOC for the rest of the mission, with the team trained to use and maintain it with the support of Airbus Defence and Space, Toulouse, the prime contractor during Gaia’s development.

The model was a whopping 4×4 m at its base, and could only be moved at night owing to its size.

We asked ESA’s Dave Milligan, the Gaia spacecraft operations manager at ESOC, for the back-story on why the AVM is being transferred now.

Dave replied:

We’re coming up to one year of operations after the commissioning period, which lasted 6 months. The first 18 months have been packed with activities not foreseen before launch for which the avionics test bench has been heavily used for validation purposes at Toulouse (e.g. changing how the spacecraft’s safe mode software works, creating new software for the 7 payload computers to deal with some issues on the telescope performance, reproducing then solving various anomalies, etc).

So, we’re moving it now for several reasons:

  • During the move, it is not available for some two months and Gaia operations are now rather stable, so we can afford to have it unavailable for a period
  • The AirbusDS team that built Gaia are dispersing onto new projects, so it makes sense to maintain the expertise/experience in Gaia avionics here at ESOC
  • The until-now high operational workload at ESOC is returning to more normal levels, so we can dedicate time to receiving, maintaining and operating the test bench