The former SpaceX executive left British rocket start-up Skyrora less than six months after joining.
Lee Rosen, who joined Edinburgh-based Skyror as chief operating officer, left the company in November, according to his LinkedIn profile.
A Skyrora spokesman said Rosen left for “personal reasons” and plans to return to California.
This is the latest blow to a space venture that hopes to use a rocket base in Shetland to launch small satellites into space.
The company’s first suborbital launch test of a Skylark L rocket from a landing site in Iceland failed, and the rocket crashed into the Norwegian ocean about 500 meters from the coast. The company blamed the outage on a “software anomaly”.
But despite not successfully launching into orbit so far, the revenue of Skyrora Ventures, its parent company, increased by 300 percent last year.
Revenue rose from £3.8m to £15.2m, according to the company’s annual report. It recorded a loss of £6.3 million.
Skyrora Ventures said it continued to develop “non-space business, including online advertising services.”
Its parent company owns a network of advertising and affiliate marketing companies, as well as dating apps and horoscope products that provide funding to Skyrora’s parent company. Skyrora said it continues to receive financial support from investors and is in the process of securing additional grants from the European Space Agency.
Skyrora was founded by Ukrainian entrepreneur Volodymyr Levykin, former director of the now-defunct dating empire Cupid PLC.
According to the Snopes report, Ukrainian Internet entrepreneur Max Polyakov is among its investors. Mr. Polyakov is a shareholder in Hong Kong-based Digitroom Holdings, which holds shares in Skyrora.
Mr. Polyakov, who founded and listed Cupid in London, founded Noosphere Ventures. He saved the US missile company Firefly from bankruptcy, but was forced to sell it earlier this year by US authorities due to national security concerns.
Mr. Polyakov posted an attack on the US decision in February on Facebook. He said: “Dear U.S. agencies that have betrayed and judged me in all their actions for the last 15 months. I hope you’re happy now.”