The Digicon, chosen by NASA as the detector for the High Resolution Spectrograph (HRS) and the Faint Object Spectrograph (FOS) is a 512 parallel output channel vacuum ptioto-detector. Where are two HRS Digicons with spectral sensitivity ranges from 1050 Å to 1800 Å and 1150 Å to 3000 Å. A respectively, and two FOS Digicons, which have spectral ranges ex-tending to 7000 Å. The significant requirements for these devices are 0.01 counts per second background count rate per diode, state-of-the-art Digicon pulse height resolution (typical 15%) and a high degree of imaging precision and stability. The results of a manu-facturing and test program to develop the Digicons coupled with extensive prior work has shown that these requirements can be met. The Digicon because of its inherent ruggedness is particularly well suited to space applications.