The imprisoned telepath in Lt. Matheson's flashback was supposed to be Lyta Alexander. However, Crusade was operating under a very strict budget, so the amount offered to Patricia Tallman was approximately 1/6 of her usual salary, and she refused.
According to Babylon 5 canon, the destruction of Psi Corps headquarters shown in Lt. Matheson's flashback claimed the life of Lennier, the renegade ranger.
The helmets worn by the soldiers in the series are the same as in the movie Starship Troopers (1997), only the color is different.
This takes place in June 2267.
The planet as seen from space has multiple topographic features identical to Earth: the Great Lakes, the Delmarva peninsula, the Rocky Mountains.