The ZGMF-X56S/γ Blast Impulse Gundam is the ZGMF-X56S Impulse Gundam equipped with the γ Blast Silhouette pack and is designed for long-range heavy assault and bombardment missions. As such, the Blast Silhouette pack is equipped with powerful range weapons in the form of two beam cannons, two rail cannons and a pair of missiles launchers. The pack also contains a pair of beam javelin for close range combat, and has additional thrusters that enable the Blast Impulse to hover over earth surfaces such as water and improve its overall mobility.
In C.E. 73, ZAFT created the Impulse as part of the Second Stage Series of new Gundam-type mobile suits. The Impulse is similar to the GAT-X105 Strike Gundam, created by the Earth Alliance during the First Alliance-PLANT War. Like the Strike, the Impulse can be equipped with exchangeable Silhouette packs, an advanced variation of the old Striker Packs, granting the suit the ability to adapt to different combat situations. One such pack is the γ Blast Silhouette, which is analogous to the AQM/E-X03 Launcher Striker.