Covenant spy probe

Small, softball sized automaton created by the Covenant. Spy Probes are small devices Covenant ships deploy at the scenes of battles. The Probe is capable of attaching itself to a ship using electromagnets. Usually it is painted dark gray to blend in to the color of UNSC vessels, instead of the standard lavender color of Covenant alloys.

The Probe has a single photo eye that gazes at the stars and collects data to reference its current position. For several days, it collects data and slowly builds up a charge. When it reaches critical energy, a tiny sliver of thallium nitride memory crystal is ejected at the speed of light, and a miniature Slipspace field is generated around it. If its trajectory is perfect, it will intercept a Covenant Receiver or vessel located at precise coordinates in Slipspace, and the tiny probe would reveal to the Covenant forces where the enemy ship had been.

A Covenant Probe attached itself to the UNSC Iroquois after The Battle of Sigma Octanus IV. This led directly to them finding the location of Reach and eventually, The Battle of Reach.