In the 1960's, the first method used by the SRON Laboratory for Space Research at Utrecht to spectroscopically image the solar corona in X-rays employed Fresnel zone plates. Four Fresnel plates, covering four specific wavelengths, were flown on Aerobee rockets in 1967 and gave a first useful Xray image of the Sun in the Si-X line at 5.1 nanometer. The techniques developed for the solar X-ray images enabled SRON to become the Principal Investigator for the grating spectrographs on several major X-ray satellites, i.e. on the Einstein and EXOSAT satellites, launched in November 1978 and May 1983 respectively, and on the Chandra and XMM-Newton observatories both launched in 1999. Since then a considerable effort was put into the development of, cryogenically cooled, non-dispersive X-ray spectrometers as potential payload elements for future X-ray missions. In that context SRON took an active part in initiatives and studies for next generation X-ray observatories like XEUS, IXO and Athena. Over the past decade ...