VMFA-121  Marine Fighter Attack Squadron 121 (VMFA-121), also known as the "Green Knights", is a United States Marine Corps aircraft squadron operating the F-35B Lightning II. The squadron is based at Marine Corps Air Station Iwakuni, Japan and falls under the command of Marine Aircraft Group 12 (MAG-12) and the 1st Marine Aircraft Wing (1st MAW). Their tail code is "VK" and their radio call sign is "Combat". Marine Fighting Squadron 121 (VMF-121) was activated on June 24, 1941. The Green Knights began combat operations flying the F4F Wildcat and later the F4U Corsair as charter members of the Cactus Air Force and throughout the Battle of Guadalcanal arriving in October 1942. The squadron also fought from the forward air bases of Espirito Santo, Turtle Bay, Bougainville, and Emirau. On September 15, 1944, the Green Knights landed on Peleliu and fought there until July 25, 1945. They returned to the United States to be deactivated on September 9, 1945. During the Pacific War, VMF-121 produced fourteen fighter aces, more than any other squadron, including Medal of Honor recipient, Major Joseph J. Foss. VMF-121 downed 208 Japanese aircraft (165 flying Wildcats and another 44 flying Corsairs) in aerial combat. After World War II, the squadron was reactivated in the United States at Naval Air Station Glenview, Illinois where the squadron's designation was changed to Marine Attack Squadron 121 (VMA-121). During this time they flew a variety of aircraft including the F4U Corsair, F8F Bearcat and A-1 Skyraider. In mid 1951, VMA-121 received orders to activate its reserve members and departed NAS Glenview for Marine Corps Air Station El Toro, California. After completion of training in the Skyraider, the squadron was transported aboard the carrier to Yokosuka, Japan to begin final preparations for a combat deployment to the Republic of Korea. In June 1953 they also set a then Marine record for a single day's ordnance delivery when 16 AD-2 Skyraiders dropped 156 tons of bombs during the attack on the Sui-ho Dam. VMA-121 deployed to K-6 Airfield at Pyongtaek, Republic of Korea on October 19, 1951 and conducted their first strike on October 27. Their mission was to conduct strike missions in support of infantry operations. The squadron dropped more bomb tonnage during the Korean War than any other Navy or Marine Corps squadron, devastating enemy airfields, supply dumps, bridges, and railroad yards.