From Halopedia, the Halo wiki
During a skirmish in the Indra Asteroid Cluster, a UNSC sniper hit a Type-52 plasma launcher round, detonating it and killing everyone within ten meters. Before Covenant reinforcements could arrive, Lieutenant Hencheck secured a Covenant weapons cache and various artifacts, loading them onto a nearby Pelican. This allowed human scientists a chance to study Covenant weaponry. Hencheck later died from radiation poisoning. In his honor the findings gathered from the weapons were known as the "Hencheck Findings."
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