Test mass enclosure elements

The centre image shows a cutaway diagram of the LISA Pathfinder inertial sensor vacuum enclosure. Photographs of engineering models of some individual subsystems are also shown. The test mass is maintained within the vacuum enclosure, kept in the caging mechanism until it has reached L1 where it can be released to drift freely. The walls of the test mass chamber have discreet electrodes attached to them, able to manipulate the free-floating test mass as needed to prevent any harmful collisions.