Heikki Sipilä graduated MSc and PhD from Technical Physics Department at Helsinki University of Technology. Heikki Sipilä’s work as Chief Scientist of the Physics Institute of Outokumpu mining and metallurgy company produced unique expertise and industrial innovations in X-ray and gamma detector technology. Heikki Sipilä became one of the founders and the Chief Scientist of Metorex International Oy, a supplier of advanced detector technology for industry and space applications. Heikki Sipilä’s initiation into detector development for space programs derived from his keen interest in understanding the physical reality and his conviction of the importance of reliable experimental data for supporting theoretical considerations. Work for space programs brought him into close co-operation with space scientists and to the installation of Metorex detectors in scientific satellites in Europe, USA, and Japan. Retirement in 2009 has given Heikki Sipilä time to penetrate into fundamentals — enriched by the experience in one of the most demanding areas of experimental physics.