Jet Propulsion Laboratory co-founder Jack Parsons was simultaneously a brilliant rocket scientist and an enthusiastic follower of Aleister Crowley's occult religion of Thelema.

A rocket laboratory and a private ritual

Jack Parsons treated rocketry and ceremonial magic as different ways of pursuing forces that ordinary life could not readily command. In the 1940s, he helped build the rocket-research effort at Caltech that became the Jet Propulsion Laboratory, while also practicing Thelema, the religious and magical system created by British occultist Aleister Crowley.

Parsons did not see the two pursuits as simple opposites. He approached ritual with a kind of technical confidence: prepare a sequence, concentrate intention, and try to produce a result. That did not make magic scientific in the modern sense; it meant he brought an engineer’s appetite for procedure into a spiritual practice.

What Babalon meant

In Thelema, Babalon is a powerful sacred feminine figure associated with freedom, desire, and the breaking of restraints. She is a religious symbol, not a goddess whose existence can be established by experiment. Parsons’s “Babalon Working” was an attempt to make contact with her through a series of magical rites.

The rites included what practitioners call sex magic: using sexual activity within a ritual, with the belief that it can focus or direct spiritual power. Science-fiction writer L. Ron Hubbard took part in the undertaking. The surviving accounts describe the pair trying to prepare for the arrival of a woman who would serve as a partner in the working, rather than demonstrating that a supernatural being had been summoned.

Two worlds in one life

Parsons’s story is striking because the same man could help develop practical rocket motors—hardware whose performance had to be tested against physical reality—and pursue a spiritual project guided by occult belief. The contrast captures a moment when amateur rocketry was still experimental and its pioneers could bring intensely personal ideas into their work and lives.

For Parsons, the ritual was not an eccentric footnote to engineering so much as another attempt to reach beyond familiar limits. The rockets were built to push machines into the sky; the Babalon Working tried, by very different means, to make an unseen force present.