The film was later released on DVD as both Reactor and War of the Robots.
The 4 films in Alfonso Brescia’s sci-fi series are Cosmos: War of the Planets (1977, a.k.a. Year Zero War in Space), Battle of the Stars (1978, a.k.a. Battle in Interstellar Space), War of the Robots (1978, a.k.a. Reactor) and Star Odyssey (1979, a.k.a. Seven Gold Men in Space)
Al Bradley [Public domain], via Wikimedia Commons