The Vostok was part of Battlegroup 4 led by Captain Veredi of the CMA Heracles that was sent to Harvest to find out what happened to the scout ship CMA Argo and the colony, itself. The battle group consisted of his own ship, the destroyer CMA Heracles, and two frigates, the CMA Arabia and the CMA Vostok. They were sent to discover the fate of the colony on the planet Harvest, where contact had recently been lost with the local populace. The Battle Group encountered a Covenant vessel holding station in Harvest orbit and the Vostok was destroyed almost instantly by the Covenant's superior firepower. All hands were lost aboard the vessel.
Its partner ship, the Arabia, was destroyed at the same time, and the badly-damaged Heracles was forced to retreat.
- Vostok (Восток) means East in Russian language. It might also be referring to the Vostok Programme, the first spaceflight project to succeed in putting a human in Earth's orbit. In addition, a Russian research station in Antarctica named Vostok recorded the coldest temperature at -90 degrees Celsius.