Scorpion Mobile Gun System

Overview:
When the Terran Hegemony was formed, the Scorpion Mobile Gun System (not to be
confused with the Scorpion Light Tank used during the Succession Wars) was
already an aging but ubiquitous combat vehicle. Developed in 2219 by Mitchell
Vehicles, it was intended as a quick response direct fire support unit for the
Terran Alliance Global Militia. Ultimately, the AGM was nonplussed by its
performance, believing it would be completely ineffective against main battle
tanks and heavier vehicles. As such, the AGM didn't initially field Scorpions
in large numbers. However, it quickly became very popular with colonial
militias because it was inexpensive and easy to maintain. This colonial demand
prompted Mitchell Vehicles to also spin up production lines at its Graham IV
factory, which had previously only produced civilian vehicles.

By the time of the Outer Reaches Rebellion, in 2236, thousands of Scorpions
were in service with the colonial militias. During the Rebellion, colonial
militias were able to use the nimble Scorpions to defeat heavier AGM units.
This performance made the AGM take note of it and cemented the Scorpions'
presence in front line units for decades to come. Scorpions were still in
service by the time of the Alliance Civil War and even in the Hegemony Armed
Forces after the fall of the Terran Alliance.

Capabilities:
The primary strength of the Scorpion MGS was its mobility. Its wheeled chassis
and powerful engine gave it a top speed of over 86 kph, faster than most light
tanks of the day. Of course, not using tracks meant it was not as able to
traverse rough terrain, forcing commanders to chose their engagements more
carefully. Its 120 mm cannon gave it moderate firepower for its time, and was
dangerous to many lighter vehicles. However, it could not provide a knockout
punch against most tanks, requiring repeated hits to disable those units.
Its only backup weapon was a single forward machine gun to ward of infantry. It
was also lightly armored, able to shrug off a hit from all but the heaviest
weapons of the day but not able to stand up to repeated hits. All of these
factors were the reasons why the AGM was initially not impressed by the
Scorpion. However, during the Outer Reaches Rebellion, colonists deployed their
Scorpions in closely coordinated combat teams, coordinating fire to bring down
opposing tanks. They also took maximum advantage of the Scorpion's mobility to
outflank slower opponents. Using these tactics, the colonial militias were able
to hand the AGM many embarrassing defeats.

Variants:
After the conclusion of the Outer Reaches Rebellion, the AGM had taken note of
the Scorpion's performance in colonial hands and began building up similar
combat teams to replace other combat losses. They also approached Mitchell
Vehicles with a request for an upgraded Scorpion. This request would ultimately
be answered with the Scorpion Mk. II in 2253. The Mk. II was one of the first
vehicles to carry the newly developed Class 5 Autocannon. It offered a longer
range and better ammunition efficiency than the 120 mm cannon of the original,
while offering similar firepower. However, it was larger and heavier than the
old cannon. To make room for the new weapon, without sacrificing the already
modest armor protection, the reliable diesel engine was replaced with a fuel
cell engine. The switch actually allowed for a moderate increase in the armor
protection and the new engine offered an even higher top speed. However, the
operational range of the new Scorpion was slightly lower and the new engine
could be temperamental in adverse conditions. To make matters worse,
maintenance on the fuel cell engine was difficult and replacement parts were
often hard to procure. All this and the 30% higher price tag prevented the
Scorpion Mk II from becoming as popular as the original.