The co-founder of NASA's Jet Propulsion Laboratory was a devout disciple of occultist Aleister Crowley who performed sex-magick rituals to summon a goddess while inventing the rocket fuel that took America to space. This is not an internet legend stitched together after the fact. It is two fully documented lives lived by one man at the same time — and the strangest part is how thoroughly the record holds up.

Start with the science, because it is real and it is enormous. John Whiteside 'Jack' Parsons, born in 1914, was a self-taught chemist obsessed with rockets at a time when 'rocket' was a word respectable scientists avoided. In the late 1930s he was part of the Caltech 'Suicide Squad' whose experiments grew into the Jet Propulsion Laboratory; he co-founded JPL and co-founded Aerojet, the rocket-engine company. His signature breakthrough was castable composite solid propellant and the JATO units — jet-assisted takeoff rockets — that boosted overloaded aircraft off short runways in World War II. The chemistry he pioneered is in the lineage of the solid boosters that later helped lift American spacecraft. There is a crater on the far side of the Moon named for him. The man's place in the actual history of spaceflight is not in dispute.

Now the other ledger, equally documented. Parsons converted to Thelema, the religion founded by the English occultist Aleister Crowley, and rose to lead the Agape Lodge, the California branch of Crowley's Ordo Templi Orientis. He corresponded directly with Crowley, who regarded him as a promising and generous disciple. The big Pasadena house Parsons ran on 'Millionaire's Row' became a bohemian commune of occultists, science-fiction writers, and assorted misfits. None of this is reconstructed gossip; it is in Crowley's own letters, in O.T.O. records, and in the FBI's security file on Parsons, which surveilled him for years over his unconventional life and his security clearance.

The centerpiece is the Babalon Working of 1946, and it is documented because Parsons wrote it down and so did his partner. Beginning in late 1945, Parsons conducted a series of rituals drawn from the Enochian magic system of John Dee, intending to incarnate the Thelemic goddess Babalon on Earth. His assistant and scribe for the operation was a young Navy officer and aspiring writer named L. Ron Hubbard — yes, the future founder of Scientology — who recorded the visions while Parsons worked the rite. When a red-haired artist named Marjorie Cameron arrived at the house, Parsons declared her the 'elemental' he had summoned, took her as his 'Scarlet Woman,' and performed sex-magick rituals to complete the working, with Hubbard still scribing. Parsons believed, in deadly earnest, that he was opening a door for a new aeon.

The skeptical reading is essential here, and it does not require dismissing any of the documented facts. Everything above is real; what is not established is that any of it worked. Parsons summoned a goddess and what he got was a failed business partnership: he, Hubbard, and Cameron's predecessor formed a venture called Allied Enterprises, into which Parsons sank most of his savings — about $20,970 — and Hubbard promptly took much of it and Parsons's then-girlfriend off toward Florida to buy yachts. Parsons chased them down and recovered only a fraction. The 'goddess working' produced, in the cold light of the bank statement, a con. That is the honest texture of occult history: sincere belief, real ritual, and outcomes fully explained by human folly.

Then there is the death, which the mystery industry overcooks but which is genuinely strange. On June 17, 1952, Parsons died in an explosion in his home laboratory in Pasadena. The official finding was accidental — he is presumed to have dropped a container of volatile fulminate of mercury. But he was a meticulous explosives professional, which has fed decades of murder-and-suicide speculation, none of it ever proven. His mother died by suicide hours after learning of his death. The case file says accident; it does not silence the people who find it implausible that an expert handled his materials so carelessly.

What the record leaves genuinely open is not whether Parsons did these things — he did, and the FBI file, Crowley's correspondence, and Parsons's own writings prove it — but what to make of a single mind that held both halves at once. He was a serious enough scientist to help invent American rocketry and a serious enough occultist to spend his nights trying to tear a hole in reality. We can document the rituals and we can document the rockets. What we cannot resolve is the question Parsons himself never separated: whether, for him, they were ever really two different projects at all.