Gaia BAM OMA bar #2
Gaia Basic Angle Monitor (BAM) Opto-Mechanical Assembly (OMA) bar #2. This is the more complex of the two bars; it houses the light source, collimator and beam splitters. It directs two of the four measurement beams onto one of the main mirrors and directs the other two to bar #1.
(Read more about the BAM in the accompanying article 'Basic Angle Monitor delivered for integration', in the right-hand menu.)