He has developed a number of his own rocket designs based on non-toxic propellants including bipropellants, hybrids and solids. His developments are made in close cooperation with the Dutch Federation for Rocket Research (NERO) of which he has been a member since 1962.
After his technical school education, Leo worked for seven years in various diciplines in the aircraft industry. He then studied at the college for marine engineering in Rotterdam, after which he spent a period of six years sailing onboard various vessels. After retiring from his sailing career he founded MEROC Consultancy, a company specialized in mechanical engineering and rocket motor design, which he still owns and operates today.