Clarion spy drones are small probes used by the UNSC that can propel themselves through space under their own power by either remote or computer guidance. They use a variety of sensors and cameras to scan space and transmit data to any ship, platform, planet, etc. They are standard issue on most UNSC vessels. They are also one of the few things that can survive a Slipspace ejection with no damage as they are almost pure Titanium-A.
They are mainly used for reconnaissance but have a variety of uses, including being used as decoys. Vice Admiral Danforth Whitcomb used one of these devices when spying on the Covenant while the UNSC Gettysburg hid behind a moon during Operation: FIRST STRIKE.