the RGM-79 Powered GM 

As the Earth Federation Forces rebuilt its military power in the years following the One Year War, it used existing units to serve as testbeds for developing technologies to be incorporated into new mobile suit designs. One such unit was the RGM-79 Powered GM, a heavily-modified suit built to test parts and systems for the Gundam Development Project. It mounted a heavy, powerful backpack that provided it with incredible thrust and acceleration, and was equipped with improved shock absorbers in the legs. The control systems for the backpack and other improvements were placed in external "boxes" on the Powered GM's armor, making it appear more heavily armored than it actually was. One Powered GM undergoing testing at Australia's Torrington Base in late UC 0083 was destroyed in pursuit of the stolen RX-78GP02A Gundam GP02A Physalis, another was damaged during the attack on Torrington Base.