Jack Parsons (1914-1952) was an American rocket engineer, chemist, and Thelemite occultist1 associated with Caltech. He was one of the principal founders of both the Jet Propulsion Laboratory (JPL) and the Aerojet Engineering Corporation.2 He invented the first rocket engine to use a castable, composite rocket propellant, and pioneered the advancement of both liquid-fuel and solid-fuel rockets.
He was friends with Robert Heinlein and Ray Bradbury.3
Konx Om Pax
Parsons found an occult book at a used car dealer’s shop in Pasadena, CA— Konx Om Pax by Aleister Crowley.4

Parsons was intrigued and attended a meeting at the Agape Lodge, a chapter of the Ordo Templi Orientis (Order of Oriental Templars). In a review of the biography, Strange Angel: The Otherworldly Life of Rocket Scientist John Whiteside Parsons, David DeVorkin, curator of the history of astronomy in the division of space history at the National Air and Space Museum wrote:5
The biography paints a reasonably good portrait of a maverick experimenter swept up in certain aspects of southern Californian technoculture: aeronautical engineering, high explosives technologies, science fantasy and fiction, and pseudoscience occultism. The author provides enough detail to help the reader appreciate how these seemingly disparate worlds were intertwined in Los Angeles culture.
There is a crater on the moon named for him.
Parson’s short life (he died at 37 in an explosion mixing fulminate of mercury in a coffee can) has been the subject of books, comics, plays and films. He was involved with L. Ron Hubbard in a yacht scam.6 There is a crater on the moon named for him. In 2018 CBS All Access produced a series about him, Strange Angel.7
Campbell, Colin D. (2018). Thelema: an introduction to the life, work & philosophy of Aleister Crowley. Woodbury, Minnesota.
Carter, John (2004). Sex and Rockets: The Occult World of Jack Parsons (new ed.). Port Townsend: Feral House.
Davis, Erik. “Babalon Launching: Jack Parsons, Rocketry, and the ‘Method of Science.’” in Magic in the Modern World. University Park, USA: Penn State University Press, 2021. 119–151.
McCook, Kathleen (2021). Golden Dawn: (Aurora Aurea):Fu Manchu, Dracula, the Tarot & Nobel Prizes. Ebla to E-Books: The Preservation and Annihilation of Memory.
Pendle, George (2005). Strange Angel: The Otherworldly Life of Rocket Scientist John Whiteside Parsons. Reviewed by David H. DeVorkin in Physics Today. Vol. 59. (January 2006).
Miller, Russell. 2015. Bare-faced messiah: the true story of L. Ron Hubbard.
Lin, Alex THE OCCULT HISTORY BEHIND NASA’S JET PROPULSION LABORATORY. Supercluster. (November 10, 2021).
A digression; Adam Curtis's documentary "All Watched Over by Machines of Loving Grace" spins a parallel tale about the intersection of woo-woo and high technology in California, although he's largely focused on the evolution of computer technology in the post-Parsons decades. (He may mention Parsons; it's been years since I've seen it). Of course, computer/information tech was the successor ideology to aviation/space-race tech...
This is certainly one of the oddest tales in modern occult history. Not only was Crowley the originator of modern thelemic ritual magick, he also perpetuated much occult lore that might have been forgotten had he not adapted it (you can call that good or bad, as you like). His poetry was way before its time (again, call that good or bad). He was supposed to have somehow conjured up the Loch Ness Monster during his residence at Boleskine House near the lake. And Parsons's thelemic ritual in the Mojave Desert in February 1946 is supposed to have ushered in the age of flying saucers (it didn't, really). Crowley reveled in obscurity and ambiguity, managing to mask his major interest in sex magick with mystical trappings of balderdash. On the other hand, he was capable of some profundities. From "The Confessions of Aleister Crowley" (1929): "The supreme satisfaction is to be able to despise one’s neighbor and this fact goes far to account for religious intolerance. It is evidently consoling to reflect that the people next door are headed for hell." And from "Magick without Tears" (1954): "We place no reliance on Virgin or Pigeon; our method is Science, our aim is Religion."