The HGA transmits data to Earth on two frequency channels (the downlink).
Imaging Science Subsystem (ISS)
The ISS is a modified version of the slow scan vidicon camera designs that were used in the earlier Mariner flights.
- Observe and characterize the circulation of the planetary atmosphere,provide limits on atmospheric composition, and determine the wind velocities in the regions observed.
- Obtain global multi-spectral coverage of all satellites; establish rotation rates and spin axis orientations.
- study the surface morphology of Triton at spatial resolutions less than 2 km.
- search for undiscovered satellites.