Project Poseidon is the Jaeger development program started by the United States Marine Corps before the start of the Second Kaiju War.
Phase one began immediately after the closure of the Pacific breach. While everybody else thought that it was the end of the war against the Kaiju, the U.S. military knew that it was only the calm before the storm. The United States Marine Corps commissioned Project Poseidon in order to develop and construct new weapons and Jaegers to combat future Kaiju threats.
During Phase one, the Anti-Kaiju Defense Battalion was formed and the construction of Devildog Ruler began as the first American Mark V Jaeger, equipped with the revolutionary Blue Spark Generation 2 operating system and powered by Boeing's cutting edge X-100 Cold Fusion Reactor, giving the Jaeger incredible staying power and flexibility in battle.
Also produced during Phase one were the AK-1000 Anti-Kaiju Rifle, the MK-91 "Slash Harken" Grappling Hooks and Juggernaut protocol, which allows an individual Ranger to pilot the Jaeger on their own for a limited amount of time.
Phase Two began immediately after the temporary closure of the Atlantic breach. The data recorded by Devildog Ruler's onboard instruments revealed that it was possible for Category VI and above Kaiju to appear from the breaches and that current tactics were ineffective and that newer Jaegers were needed to intercept these Kaiju before they made landfall.
During Phase two, the development and construction of the Mark VI Jaeger Leatherneck Omega became such a huge undertaking, the United States Navy joined in to improve and create new weapons as well as installing the improved Blue Spark Generation 3 OS and Boeing's improved X-110 Cold Fusion Reactor, making it an effective first strike Jaeger.
Also produced during this phase were the AK-900 Anti-Kaiju Shotgun, the MZ-700 Plasma Rifle and DK-70 Energy Blades as well as the T-20 Dragon Wings, which are an improved variant of the T-16 Angel Wings, allowing the Jaeger to fly under its own power.
Phase Three began at the Miami Emergency Shatterdome after the sudden appearance of Precursor Danger on the US Eastern Seaboard in an attack that damaged Leatherneck Omega and required the reactivation of Devildog Ruler. To compensate for this encounter, the entire US Armed Forces was tasked alongside the Pan Atlantic Defense Corps with developing and deploying weapons designed to not only kill Kaiju but also destroy Precursor Danger if it shows up again.
This would lead to the construction of a new type of Jaeger that would be named FILE REDACTED. More in 2016.