Hey there. Not bad translation at all^^
Basisverteidigung means "Basic Defence". translate "Basis" (could be Base or basic), and Verteidigung (means Defence).

Google Translate plus my best attempt at de-Engrishing:

The Titan Supertanker was primarily used for transporting fuels and other cargo in interstellar space. When the Great War broke out, they armed it with point-defense guns and used it primarily for logistics support of their fleets.
The Titan was not cheap in its production, despite its easy to obtain building materials, but its size was suitable to its new role and its design simple enough to build.
Despite the added firepower on* the military version, the Titan couldn't effectively protect itself from attacks in deep space, which is why it was often accompanied by a convoy.

*"Baisverteidigung": Google couldn't translate this word, so I filled in as well as I could based on context.

If I got anything wrong, please let me know :)