Principal guider mechanical assembly has started
The center field guider as of 8/3/01. The CFG carries two sets of optics, one for guiding, and a second for center field Shack-Hartmann sensing of the telescope primary mirror. The two optical systems are exchanged under computer control. When using the CFG, the camera/lens assembly moves into the center of the field.
A THK actuator drives the CFG in and out of the active position.