ESA Science & Technology - Constructing the LISA Pathfinder flight optical bench

The LISA Pathfinder flight optical bench pictured during construction. The "tombstone" components are precision bonded to the optical bench. The bench is a 20cm by 20cm block of Zerodur ceramic glass. The components that require high precision alignment are bonded individually. Each is positioned against ruby balls that are mounted on micrometer and piezo driven stages. The positions of the ruby balls are varied until the component is in the correct position. The component is then hydroxide-catalysis bonded into place.