A film that may provide some explanation for the similarities between Alien (dir. Scott, 1979) and The Ark In Space (1975) is Dark Star (dir. Carpenter, 1974). Released a year before The Ark in Space, it is a possible influence, and also happens to be written by Dan O’ Bannon, who wrote Alien.
Dark Star is also critical of conformism, featuring an irritable crew who are repressed by the conformism and regimentation of their work. The crew must address each other by their surnames, and this reaches such extremes that at one point a crew member confesses he has forgotten his first name. The crew talk wistfully of the individual hobbies they had back on Earth. Lt. Doolittle (Brian Narelle) talks endlessly of his love for surfing. While the deceased Commander Powell (Joe Saunders), who is kept in stasis by being merged with the ship’s computer, once revived, talks of his love for football, but forgets important facts about his favourite team, as the ships systems rob him of his identity. The Ark in Space also uses man’s merger with technology as a metaphor for conformity, and Alien uses the idea to suggest possible dangers of gender-equality. The ship’s computer in Dark Star is also named Mother, an obvious influence on Alien, and a possible inspiration for the artificial family unit in The Ark in Space. The end of the film sees the ship’s destruction, but Lt. Doolittle rides to safety on a surfboard he forms from the wreckage. This represents him rejecting the mechanical conformity that the ship symbolised, as he creates a symbol of his individuality from its remains and rides it to freedom
Dark Star also features a destructive alien creature, but it is mostly used for comic relief, presented as a mischievous gremlin rather than a deadly menace. It is possible that both Alien and Ark merely developed the themes of Dark Star, choosing to enlarge the role of the monster and have it symbolise their chosen thematic evil. However, this does not explain the technical similarities between each work’s alien creature, such as their gestation inside a human host and their multiple life cycles. Although I have not seen the films, I have heard that the Alien creature was also inspired by parasitical monsters from the B-movies, It! The Terror From Beyond Space (Dir. Cahn, 1958) and Planet of the Vampires (Dir. Bava, 1965). Perhaps the Wirrn was also inspired by these creatures? If not, the similarities between The Ark in Space and Alien are either a massive coincidence or the creators of Alien owe the creators of The Ark in Space a huge debt, which, as of yet, has not been expressed.