Thor-class cruise missile

Thor cruise missile was a long-ranged anti-shipping missile used by the CMA Navy and UNSC Navy during the Pax Humana.

Description
Prior to the UNSC-CMA Cold War, the lack of adequate armour material capable of providing reliable protection against more than one or two hits meant that space battles often took place over extraordinary distances, as neither side was willing to enter the effective range of their opponent's missiles. Fighting at these distances was only capable with long-range cruise missiles, which had enough fuel and speed to reach their opponent within an acceptable time frame. This placed an emphasis not on agility, but sheer speed and the use of multiple warheads in order to maximise the success of their attack, with an opponent's only option being to deploy countermeasures and attempt to dodge. As they were equivalent in size to missiles like the Hyperion, they could only be used by universal silos rated for Class-6 devices.

Thor cruise missiles were the most successful line of superheavy cruise missiles, and were employed as standard weapons in arsenal ships and as the heavy weapons aboard patrol cruisers like the Diligence-class. Built as lightly as possible without compromising structural integrity, they were the direct predecessors of fusion missiles, differing only by their use of high-powered rocket engines instead of fusion drives which made them able to correct their course mid-flight. With a body measuring dozens of metres long, they could strike at targets hundreds of thousands of kilometres away from their launching site. Their warheads were divided into three equally-sized submunitions that lacked their own propulsion, being launched within kill range of their target.

Ultimately, like the rest of their kind, Thor cruise missiles were made completely obsolete by the development of Titanium-A battleplate. Only nuclear-armed versions were capable of breaching the protective plating and causing damage, which were in both regulated supply following the Hydra System Massacres and still potentially able to be intercepted by countermeasures. As a result, the Thor was swiftly replaced during the UNSC-CMA Cold War in favour of more agile missiles in naval service.

The extreme range of cruise missiles, however, did make them useful in a planetary defence role. As a result, during the Human-Covenant War stockpiles of surviving Thors were reconditioned and used in planetary launch sites, either for intercontinental strike or assisting in defence of the planet.

M19 Thor
The standard model by the end of the Pax Humana.