See also: History of RB-79 Ball
At the beginning of the One Year War with the Principality of Zeon, the Federation lacked any sort of mobile suits while the Zeon forces held the upper hand in the war with their mobile suits.
The Federation developed a prototype mobile suit, the RX-78-2 Gundam, but it was too costly to be mass produced. Their first mass-production mobile suit, the RGM-79 GM, was not produced fast enough to be deployed at all battle fronts. Thus, the Federation refitted around 1,200 civilian-use SP-W03 Space Pods to be deployed in combat.
RB-79K Ball Type K cockpit
As an improvised conversion, the Ball was initially seen as ill-suited for combat. It earned the unfavourable nickname “Mobile Coffin” among Earth Federation Space Force (EFSF) pilots. However, it was smaller, more manoeuvrable, and more stealthy than a mobile suit. The Federation stuck to it for its low production cost and availability in large numbers. The fast Salamis-class cruisers and their attached Ball squads harassed Zeon supply fleets with hit-and-run attacks, resulting in Zeon deploying additional forces to escort their vulnerable Papua- and Pazock-class transport ships.
See also: Design of RB-79 Ball
The RB-79K Ball Type K was similar to the RB-79 Ball but it had two 180 mm recoilless cannon mounted instead of one. It was also equipped with larger manipulator arms and a rocket-guided cable grappling wench.
While travelling to Earth, the transport that Shiro Amada was on intercepted a distress signal from a damaged GM. He launched in a Ball Type K in an attempt to rescue it. He is able to save the GM pilot, Terry Sanders Jr., and destroy a MS-06RD-4 Zaku II Test Type unit in the process. This was a feat given the superiority of the mobile suit over the mobile pod. The Ball Type K was badly damaged and exploded shortly after the occupants escaped.
Behind the scenes
Hajime Katoki is the original mechanical designer.