Future detectors and arrays for visible, IR, and submillimeter imaging and spectroscopy require much higher speed digitizers than are currently available. In particular, low-power (< 5 W) space-qualifiable digitizers with > 5 GHz bandwidth and > 5 Gs/s sampling rates are needed to enable next generation digital submillimeter spectrometers. These digitizers must also provide data reduction and interface to typical digital processing logic using e.g. LVDS-compatible I/O. To meet these needs, Hittite proposes an innovative digitizer combining a high-speed (10 Gs/s), wideband (10 GHz), moderate-resolution (4 -- 6 bit) ADC with a companion digital demux to reduce the data rate and present LVDS-compatible outputs to e.g. Xilinx Virtex-5 FPGAs. The proposed SiGe HBT technology offers high reliability and radiation tolerance for space missions. A conceptual design will be developed in Phase I, and prototype digitizer modules produced during Phase II. Although a two-chip solution is initially proposed to reduce development risk, the technology will facilitate a single-chip solution during Phase III to further reduce size, weight, and power while improving system reliability.