This episode was directed by LeVar Burton, who played Geordi La Forge in Star Trek: The Next Generation (1987).
Roxann Dawson went on to provide another computer voice (for the automated repair station) in Dead Stop (2002).
The Dreadnought is said to carry 1000 kilograms (1 metric ton) of antimatter. When combined with 1 metric ton of matter, it would release the energy equivalent of 42,000 megatons of TNT, which is 2.8 million times the power of the Hiroshima bomb (which converted only 0.7 grams of matter to energy) and 840 times the power of the Tsar Bomba (the largest hydrogen bomb ever tested).
This is a turn-around of The Doomsday Machine (1967), whereby a powerfully destructive mindless machine, a remnant of some unknown alien war, wanders into our galaxy and must be destroyed. Here, the machine is smart rather than dumb, is from a known war, and attempts to destroy it come from the people who sent it out and lost track of it.
Kellan's outfit is a reuse of the costume worn by Richard Kiley as Gideon Seyetik in Second Sight (1993).