The capabilities of conventional optical systems and detectors have proved inadequate for many measurements in space astronomy. In order to overcome these limitations a family of photoelectric photon-counting array detectors has been developed for use in instruments on space-borne telescopes. The Multi-Anode Microchannel Array (MAMA) detector system can be operated in a windowless configuration at extreme-ultraviolet and soft x-ray wavelengths or in a sealed configuration at ultraviolet and visible wave-lengths. MAMA detectors with up to (512 x 512)-pixels are now under evaluation. In this paper the construction and modes-of-operation of the MAMA detectors are described and the designs of spectrometers utilizing the array detectors are outlined.