Kamchatka, the 5th planet in the Caspar system, is a Forerunner created planet. This remote planet served as a node of the Domain for the Forerunner's Ecumene. After the Halo Arrays were fired, Kamchatka was abandoned and remained as such until the planet's re-discovery in 2558. By 2558, the link to the Domain remained intact, but no apparent sentient life was present.
Kamchatka was astroengineered by Forerunner Builders to serve as a link to the Domain, a knowledge network all Forerunner Ancillas could tap in to. After the Halo Arrays were fired at approximate 100,000 BCE, the Forerunners disappeared and as such their hold on the planet. This caused the planet to regress into a planet without sentient life, and all ground-level facilities were worn away over the years.
The planet would remain as such until it was re-discovered in 2558 by both the United Nations Space Command and Jul 'Mdama's Covenant . The Covenant build an outpost on Kamchatka and were using their hostage, doctor Catherine Halsey, to access the planet's data network. During her investigation of the network, Halsey discovered information relating to the recent attacks by Guardians on human colonies. Halsey used the planet's network to contact the UNSC, Fireteam Osiris was tasked with extracting her from Covenant captivity. Osiris was deployed on Kamchatka and used the ensuing battle to sneak past many armed forces and make their way to Jul 'Mdama and Dr Halsey. In the race toward 'Mdama and Halsey, Osiris had to fight both Jul 'Mdama's Covenant and Forerunner Prometheans, making short alliances underway. When Osiris finally met up with Jul 'Mdama and his personal guards, Osiris was able to defeat and kill 'Mdama. Osiris brought Halsey back to the UNSC Infinity, which soon left the system.
Some time after the battle, the UNSC intended to establish a military complex and power station on Kamchatka to control the planet's Forerunner sites. While the UNSC is aware of the Forerunner structures under Kamchatka's surface, no detailed surveys have been conducted to observe them as of 2558.
Although the planet does not host structures and facilities at ground-level, it has an abundance of structures buried under its snow and ice. One of the more distinct natural structures is the Stormbreak mountain range, considered to be "the broken spine" of Kamchatka, this was later mended by the Forerunners.
- Kamchatka shares its name with a peninsula in Russia.
- The Halo 5: Guardians multiplayer maps March on Stormbreak and Summit are set on Kamchatka.