On October 12, 1944, Joltin’ Josie, The Pacific Pioneer, a 873rd Bomb Squadron, 498th Bomb Group B-29, landed on Isely Field, Saipan with Brig. General Haywood S. “Possum” Hansell, Jr. at the controls. Joltin’ Josie was the first B-29 to reach the Mariana Islands. The 498th Bomb Group was assigned to the 73rd Bombardment Wing, which was commanded by Brig. General Emmett “Rosy” O’Donnell. The 497th, 499th and 500th Bomb Groups were also assigned to the 73rd BW.

A total of six “shakedown” missions were flown by the B-29s of the 73rd BW against Truk and Iwo Jima prior to any missions being flown against targets in the Japanese Homeland. Two retaliatory strikes against Motoyama Airfiled #1 and Motoyama Airfield #2 were carried out on November 5th and 11th after Japanese aircraft on Iwo Jima staged a low-level raid on Isely Field on November 2nd damaging several B-29s.

Thumper, a 870th BS/497th BG B-29, participated in one of the bombing missions against Iwo Jima. The Iwo Jima bombing mission was the second mission flown by Thumper; Truk being the first. At the time this photo was taken, Thumper had also flown five missions against targets in Tokyo, and one mission against targets in Nagoya.

As can be seen from the photo above, its mission symbols were a smaller version of its cartoon nose art with the name of the target location printed on the bomb. Aerial victories were noted by a Japanese flag carried by cartoon character.

References:

How the Superfortress Paced the Attack Against Japan, Major James M. Boyle, USAF, Air Force Magazine, December, 1964.