There is a great deal of interest in the Martian satellites because
 they are most likely captured asteroids and they may have a
 substantial resource potential that could be an important factor in
 future human and robotic spacecraft exploration of Mars.
   We propose to use ISO-SWS in SWS01 mode to observe Phobos and
 Deimos from 2.4 to 45.2 microns.  Our primary scientific goals are:
 (1) To search for absorption features in spectra of Phobos and Deimos
 arising from silicates, hydrates, and possibly organic (C-H bearing)
 materials; and (2) to define the overall infrared spectral character of
 these objects in order to constrain their origin and evolution.
   These observations will help to solve several outstanding scientific
 problems related to these objects.  First, the IR continuum spectral
 behavior and the presence of specific silicate absorption features will
 allow the satellites to be classified within the current visible
 to near-IR asteroid classification scheme (no previous mid-IR spectra
 of either satellite have been obtained). Second, the observations will
 measure the hydration state of the satellites based on the strength of
 hydrated mineral absorption bands near 3.0 and 6.2 microns.
   ISO is required for these observations because many of the most
 diagnostic silicate and hydrate absorption features occur at infrared
 wavelengths that are inaccessible from the ground.  Secondly, ISO has
 superior sensitivity over groundbased instruments to detect these faint
 objects that are fairly close to Mars.