  A long-standing problem of astrophysical research is how to simultaneously
obtain spectra of thousands of sources randomly positioned in the field of view
of a telescope. Digital Micromirror Devices, used as optical switches, provide
a most powerful solution allowing to design a new generation of instruments
with unprecedented capabilities. We illustrate the key factors
(opto-mechanical, cryo-thermal, cosmic radiation environment,...) that
constrain the design of DMD-based multi-object spectrographs, with particular
emphasis on the IR spectroscopic channel onboard the EUCLID mission, currently
considered by the European Space Agency for a 2017 launch date.
