- "Did I tell you about Stewart? Now there was a lovely girl. The most precious cargo we brought along. She was... to be the new "Eve"."
- ―George Taylor
Lieutenant Maryann Stewart was a female astronaut who accompanied George Taylor, John Landon and Dodge on their fate-filled expedition through space. Six months into their mission, the crew placed themselves into a state of suspended animation, in preparation for their long voyage. While they slept, their space vessel, the Liberty 1 (nicknamed "Icarus"), passed through a Hasslein Curve in space, and was propelled forward through time several thousands of years. During their journey, Stewart's stasis pod malfunctioned and an air leak caused her to die in her sleep. When Taylor and the others finally awakened in the 40th century, they found the remains of Stewart's dessicated body in the pod. The ship crashed down onto Earth in the middle of a salt lake. Taylor, Dodge and Landon were forced to evacuate the ship, and Stewart's body sank to the bottom of the lake along with the rest of the ship.
An 'ANSA Public Service Announcement' (a bonus feature from the Blu-Ray Planet of the Apes Box-Set released in November 2008) gave her the first name Maryann and included this biography: "Lieutenant Maryann Stewart, 33, is both a career astronaut and a respected biological researcher. A veteran of ANSA's Apollo and Juno space programs, she brings experience, curiosity, and old-fashioned guts to the team."
The 2011 novel Conspiracy of the Planet of the Apes and its 2018 sequel Death of the Planet of the Apes revealed more details of her life, inspired in part by the 'ANSA Public Service Announcement'. Maryann Stewart was initially a NASA astronaut but transferred to ANSA and covertly become the joint-first American woman in space aboard the Probe Six. She had an affair with Taylor and the two plotted to find out more about the classified ‘Churchdoor’ project. Stewart was biologist with the Juno mission between Mars and Jupiter, where she briefly took control after the death of their skipper and two other crew members and the injury of Jones, and where she had an affair with the already married Landon. She, Landon and Taylor were all later assigned to the Liberty 1 mission. Dr. Milo discovered Stewart's corpse when he found the ship submerged in the Forbidden Zone.
- Stewart's rank of 'Lieutenant' was spoken on-screen by Taylor in Planet of the Apes.
- A 2007 fan-produced reproduction of the Presidential Commission's Briefing Dossier gave Stewart the name 'Dr. Diane Stewart' (Medical Officer).
- Only three astronauts are featured in Pierre Boulle's original novel, La Planète des singes (unless one counts the unfortunate chimp companion/mascot Hector). A fourth male astronaut was added by Rod Serling in his script proposals from late 1964. His name was initially 'Blake' (most likely a joking reference to director Blake Edwards' withdrawal from the project at that time) before becoming 'Stewart' by February 1965, but he was always destined to die at the start of the movie. Only the astronaut's gender was changed by Michael Wilson in his final shooting script. Rod Serling's script treatment for an 'Apes' TV show followed on somewhat from his film plot, with two astronauts sent to rescue Taylor's crew which included 'Bengsten' (possibly a 23-year-old man, who is found to have died from a broken neck).
- For years, rumors abounded that actress Natalie Trundy (the future wife of producer Arthur P. Jacobs) played the part of Stewart. Although Trundy played several different characters in the POTA mythos, the role of Stewart was actually played by Diane Stanley
- A dummy was prepared for the scenes showing the long-deceased Stewart. To achieve a realistic look for the corpse, a life mask of Diane Stanley was made, over which was sculptured her 'decomposed' features. "This was done to retain her likeness thru the effects of decay", make-up designer John Chambers explained, and while there was no question but that the face was exactly as it should be, Chambers was not happy with the over-all effect: "It was the body. It just didn't look dead, because they were using a manikin!"
- Instead, Chambers auditioned elderly extras until he finally found what he was looking for: "She was 83 years old and fit the part perfectly. And this was her first acting job!" The sequence showing the discovery of Stewart was filmed with the 'live' corpse and Chambers was satisfied with the results, as Charlton Heston's published diaries confirm: "Included in the cast (as the long dead Stewart) was an eighty-year old woman who played what must surely be the only role in the history of drama as an octogenarian lady astronaut".
- However, the dummy was used in Stewart's final shot when water starts flooding into the ship. As the arms of the dummy weren't crossed - as they had been by the two actresses - this produced a continuity error.
- Planet of the Apes
- Planet of the Apes Magazine: Planet of the Apes (issue #1)
- Adventures on the Planet of the Apes: Planet of the Apes (issue #1)
- Conspiracy of the Planet of the Apes
- Death of the Planet of the Apes
- Stewart (Visionaries), for the Planet of the Apes: Visionaries analog based on Rod Serling's first draft of the script.
- Drew Gaska interview, by Dave Ballard - 'Simian Scrolls' #16 (2010)
- Presidential Commission's Briefing Dossier at Hunter's Planet of the Apes Archive
- Rod Serling's Third 'Planet of the Apes' Draft
- The Making of Planet of the Apes, by J.W. Rinzler (2018)
- Hunter's Planet of the Apes Scripts Archive
- Diane Stanley profile at the Internet Movie Database (IMDB)
- The Forbidden Zone
- Mad Mad Mad Monkey World - fantastic facts from the (grr)ape-vine - 'Famous Monsters of Filmland' (October 1968)
- The Actor's Life: Journals 1956-1976 by Charlton Heston (1978)