- "That's what I'm worried about, later. Later we'll do something about pollution! Later we'll do something about the population exploding! Later we'll do something about the nuclear war! You act as if we have all the time in the world. How much time has the world got! Somebody has to begin to care.
- ― Dr. Otto Hasslein
Dr. Otto Hasslein was a physicist and special scientific advisor to The President.
Space flight project sent astronauts Taylor, Dodge, Landon, Stewart, Maddox and Brent to the world of the apes through something called a Hasslein Time Curve – a form of time dilation possible with their spacecraft. It's assumed that this was named after the Dr. Hasslein who is finally revealed when Doctors Milo, Zira and Cornelius travel through time in the other direction (Milo being killed by a primitive gorilla shortly after arriving).
Working at ANSA, Hasslein had organized the Juno mission, which sent six astronauts (including Landon, Stewart and Jones) between Mars and Jupiter in order to test hibernation pods and Hasslein's 'X-Comm' technology, and to officially 'claim' Jupiter for the United States. Hasslein then organised the Liberty 1 mission and urged General Lazenbe to send a second craft, the Liberty 2, if not to rescue the first crew then to test his time-travel theory.
Hasslein learned that the talking chimpanzee "ape-o-nauts" had actually arrived in the present day (1973) from Earth's own future, where mankind had fallen to the level of beasts while apes rose to power and intellect. While the other members of the Presidential Commission appointed to deal with "alien visitors" were initially skeptical of the time-travel story, Hasslein believed them, seeing it as confirmation of his theories. He privately became very suspicious of what their arrival could mean for mankind; afraid that the pair's presence might somehow set man's downfall in motion. He explained to a television news presenter his theories of time, and his belief that changing the future may be possible. He analogized time to be a highway with an infinite number of lanes, all going from the past to the future; by changing lanes, one can change destiny (see 'Trivia').
After gaining their trust, the apes revealed to him Earth's eventual fate. As the President's science advisor, he expressed his concerns, resulting in Cornelius and Zira first being taken into custody, then interrogated at length. Provoked by Zira's drugged admissions of her experimentation on humans, and Cornelius giving details of his historical research into man's decline, the Presidential Commission concluded (in a reflection of Taylor's fate before the ape tribunal) that the couple's unborn fetus should be "prevented" from birth, and that Zira and Cornelius should be "humanely rendered incapable" of conceiving again, with their ultimate fate to be decided later – at Hasslein's determination - though it appeared likely they would be handed over either to scientists or the military for study.
When Cornelius and Zira escaped military custody (at the beginnings of Zira's labor pains), Hasslein lobbied the President to kill the apes before they could threaten man's existence, and mounted a full-scale hunt, including searches of all local circuses and zoos. Days later, a carpet bag abandoned by Zira turned up near the derelict shipyard where they had been hiding, and the pair were spotted soon afterward with Zira carrying a baby chimp - Hasslein now knew she had given birth. Boarding their ship, Hasslein approached Zira, pistol in hand, and demanded she give him the baby, as the authorities approached. Before they arrived, he shot Zira and fired several shots into the swaddling blankets. Cornelius, who had earlier asked Lewis Dixon for a pistol "to kill ourselves" and avoid being captured, now used the pistol to avenge his wife, shooting at Hasslein from a crow's nest on the ship. As the authorities arrived, Hasslein and Cornelius traded gunfire. Cornelius killed Hasslein, but was himself killed by sharpshooters, falling to the deck. Despite Hasslein's best intentions, the baby he killed was not the offspring of Zira and Cornelius – and his treatment of them may have just set in motion everything Hasslein hoped to prevent.
- Hasslein is the main antagonist of Escape from the Planet of the Apes.
- Hasslein's name appeared for the first time in Michael Wilson's script treatment for Planet of the Apes in early 1967.
- Hasslein was named Victor Hasslein in the novelization of Escape from the Planet of the Apes.
- There are strong parallels between Dr. Hasslein's role and that of Dr. Zaius, in that both characters dreaded the arrival of intelligent species other than themselves, and frantically worked to keep their own societies from learning the truth.
- Planet Of The Apes (Game Boy) faithfully recreated the opening scenes of the original Planet of the Apes movie as part of its introduction, but referred to "Dr. Hesline's theory of time" (rather than 'Dr. Hasslein').
- In the first episode of Return to the Planet of the Apes, astronaut Bill Hudson credits a "Dr. Stanton" as the originator of the time theory instead of Dr. Hasslein.
- The theory described by Hasslein in his TV interview, known as "many-worlds interpretation," was first advanced in 1957 as "relative state formation" by Hugh Everett, and was popularised in the 1960s and 70s by Bryce Seligman DeWitt who applied its lasting name. Hasslein mentions neither real-life scientist in the film.
- MAD Magazine, known for the work of artist Mort Drucker who spoofed films, written back-to-back parodies of the first four films. Drucker's work was known for good likenesses of the original actors. The spoof of Escape is called Escape from the Planet that Went Apes and spoofed Hasslein as "Dr. Hassled". Zira expresses fear of her pregnancy being known, and Cornelius replies "You mean Dr. Hassled does not like apes?" to which Zira replies "That is putting it mildly. He was the only man who ever picketed a revival showing of King Kong!" However, Hasslein's spoof was mistakingly drawn as the model of Bradford Dillman instead of Eric Braeden.
- Escape from the Planet of the Apes
- Escape from the Planet of the Apes (novel)
- Escape from the Planet of the Apes (Power Records)
- Planet of the Apes Magazine: Escape from the Planet of the Apes
- Conspiracy of the Planet of the Apes