A former executive for Elon Musk’s SpaceX has quit Scottish rocket start-up Skyrora less than six months after joining the company.

Lee Rosen signed up as Edinburgh-headquartered Skyrora’s chief operations officer in June but, according to the company, has departed suddenly for “personal reasons” and returned to California.

Mr Rosen, a retired US Air Force colonel and former VP at SpaceX, is a veteran of more than 150 missions.

He spent 23 years in the US Air Force with command tours at both launch bases, Vandenberg Air Force Base and Cape Canaveral, prior to joining SpaceX. 

It is another setback to Skyrora’s plans to fire small satellites into space from a base on the Shetland islands. A suborbital launch test of its Skylark L rocket in Iceland failed, which was blamed on a “software related anomaly”.

Skyrora was founded by Ukranian entrepreneur Volodymyr Levykin, a former executive at now defunct dating empire Cupid PLC.

Its investors include Ukrainian internet entrepreneur Max Polyakov, according to a report by Snopes. Mr Polyakov is a shareholder at Hong Kong-based Digitroom Holdings, which owns a stake in Skyrora. 

Despite the latest problems, revenues at Skyrora Ventures, its parent company, jumped from £3.8m to £15.2m. It reported a loss of £6.3m.