“The mark I howitzer fires heavy, high-explosive shells.”

Since it is rather useless to think of targeting by trajectory ballistics in the zero-gravity space (not that this mean that you can ignore gravitation on real interplanetary travel, however), in this game a “howitzer” refers to a heavy, single-shot and long-ranged artillery with nonnegligible recoil.

The Mark I howitzer is the lightest and weakest of its kind, yet far more powerful and works with less power compared to most other weapons of the same level. The recoil itself can be handy as a substitute for a retro-thruster. The drawback is that the fire rate is very slow and mostly useless against swarms of smaller gunships.