Satellites that take advantage of, or require constant availability of sunlight on the spacecraft itself, available in Sun-synchronous orbits?

Question

ditto: "Are there satellites that take advantage of, or require constant availability of sunlight on the spacecraft itself, available in Sun-synchronous orbits?"

This question is an offshoot of this answer.

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As a clarifying example of what "take advantage of... availability of sunlight" means as requested in comments, a satellite could, potentially, substantially reduce the volume and mass of its battery if it could take advantage of the constant availability of sunlight in a Sun-synchronous orbit. Depending on specifics, it might still require a small battery for backup of critical low-level functions. That's just a hypothetical example for clarification purposes.

A clarifying counterexample would be a satellite that takes advantage of the constant availability sunlight reaching the Earth's surface so that it can be photographed.

Answer 1

Two classical examples of spacecraft which "take advantage" of being (almost) constantly insolated:

1- Sun Observation Missions:

Spacecraft in Lagrange's points such as SOHO or in dawn-dusk orbit such as PROBA-2 want to look at the sun, because that is what their payloads were made for. No eclipse time means no interruption of the data flow.

2- Synthetic Aperture Radars

SAR antennas require a really high peak power. Because of that, some satellites such as TerraSAR-X or RADARSAT-2 also operate in dawn-dusk orbit and can only turn on the payload when it's possible to drain power form both the solar arrays and the battery simultaneously.