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Armstrong cluster campaign "Operation: Arrowhead" Part of the Eden Prime War
Battle of Rayingri battle arrangement
Date:	17 June - 4 July 2183 CE (18 days)
Location:	Armstrong / Milky Way Galaxy
Outcome:	Operational Alliance victory Saren's Alliance' expelled from the cluster Saren Arterius suspends Operation: Window indefinitely Geth heretic fortifications destroyed and razed Systems Alliance seize control of the cluster to check any further geth movements Heretic Reserve Fleet forced to withdraw
Territorial changes:	Geth heretic gains during the Armstrong offensive are reversed
Engagements:	Skirmish on Casbin Skirmish on Maji Raid on Antibaar Battle of Rayingri Raid on Solcrum Battle of Armstrong
Belligerents Systems Alliance Saren's Alliance Geth Heretics Commanders Marcus L. Shepard Steven Hackett Unit Y5552 Strength Systems Alliance Marine Corps 72nd Expeditionary Force Systems Alliance Navy Fifth Fleet 56 Saratoga-class light cruisers SSV Saratoga SSV Pyongyang SSV Seoul 40 Geneva-class heavy cruisers SSV Tokyo SSV Cape Town 104 Mermaid-class corvettes 91 Warsaw-class light frigates 33 Melbourne-class heavy frigates SSV Melbourne SSV Hawthorne 1 Normandy-class stealth frigate SSV Normandy 3 Nelson-class carriers SSV Nobunaga 2 Charles de Gaulle-class supercarriers SSV Margaret Thatcher SSV Ulysses S. Grant 1 Kilimanjaro-class dreadnought SSV McKinley 220 SX3 Thunderbolt fighters 89 SX5 Yellowjacket interceptors Normandy Squad 7 combatants 1 M35 Mako Geth Heretic Army 11,200 geth troops 56 geth recon drones 141 geth assault drones 6,894 geth troopers 1,800 geth destroyers 1,024 geth juggernauts 940 geth hoppers 310 geth primes 26 geth armatures 9 geth colossi Geth Heretic Navy Heretic Reserve Fleet 1 geth dreadnought 5 geth battleships 26 geth heavy cruisers 10 geth light cruisers 23 geth heavy frigates 48 geth light frigates 200 geth strike fighters 130 geth dropships Casualties 9 ships destroyed, 23 damaged Around 6,000 geth troops 42 ships destroyed, 18 damaged

"This incursion could mean a full-scale geth invasion is brewing. Our job is to stop it, at any means necessary. If these geth are allowed to mobilize unmolested...the Alliance would never assemble quick enough to stop them from reaching Earth."

— Shepard.

The Armstrong cluster campaign, known to the Alliance by its operational codename Operation Arrowhead, was a multi-phase campaign spearheaded by the SSV Normandy. The battle was fought between members of the Normandy crew and the large amount of geth heretic forces setting up fortifications in the cluster. Fought across numerous worlds from June 17 to July 4, 2183 CE, the battle was a strategic success for the Alliance, and landed a critical blow to geth operations in the area, ensuring that geth mobilization of that scale on the Alliance frontier would never occur again.