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James Webb Space Telescope
FGS - Fine Guidance Sensor

FGS Optical Assembly

FGS Optical Assembly
FGS Optical Assembly
FGS ETU Test Setup
FGS ETU Test Setup

FGS Features

Functions

The FGS has three main functions:

During on-orbit commissioning of the JWST, the FGS will also provide pointing error signals during activities to achieve alignment and phasing of the segments of the deployable primary mirror.