Technology & Combat Characteristics
The RGM-89ST-2 ST-Gun was originally a RGM-89J Jegan Normal Type transferred to SNRI by Anaheim Electronics (in a move that baffled many). In order to collect the performance data of Gundam F90 while also acting as an early warning system for the testing area, it was heavily modified.
Its forehead sensor was enlarged, and it was fitted with a large radome, various types of sensors and cameras, as well as a large memory bank and data processor for storing and processing testing data. In order to keep up with the F90, it was equipped with more powerful thrusters and a generator with higher output. However, since the sensor equipment uses up most of the power, the suit itself has less power to draw on.
As a reconnaissance mobile suit the ST-Gun is not particularly suited to combat. Most of the Jegan's standard armaments have been removed in order to make room for and conserve power for the sensors. The one exception is the pair of three tube rocket grenade launchers mounted on the waist. Because of this lack of weaponry it is vital that the ST-Gun move with a protective escort when in hostile territory.
One ST-Gun was part of the Federation's 13th independent mobile corps when it was assigned to travel to Mars to combat the Oldsmobile Army. After the Mars Zeon ambush in space the ST-Gun, piloted by Navi, was one of the few survivors to make it to the surface along with a modified AMS-119 Geara Doga piloted by Sid Amber and the F90 Gundam Formula 90 piloted by Def Stallion. The three would combat the Mars Zeon ground forces however in the first battle the ST-Gun would be heavily damage, rendering it unable to move. This allowed Mars Zeon forces to capture the ST-Gun. Navi would be rescued but the ST-Gun would be lost when the base was destroyed.
- In Entertainment Bible MS Encyclopedia Vol. 7, the ST-Gun's full name was listed as "Strategic Trainer Jegan", though it was misspelled as "Strategik Treaner Jegan". The entry also listed its model number as RGM-79A. B-Club Vol. 66 stated that ST stood for "Sensor Turret" instead.
- Despite the settings stating that the ST-Gun has improved thrusters, its total thrust is actually lower than the Jegan Normal Type.