SCIENTIFIC ABSTRACT		
We propose to make spectroscopic observations of Mars using all of the ISO 
instruments.  The main scientific goals are:

  -  To characterise the shape and variability of the Martian FIR 
     continuum spectrum.  This will characterise large-scale seasonal 
     and topographic variations of the thermo-physical properies 
     (albedo and thermal inertia) of the surface.
  
  -  To determine the absolute FIR brightness temperature spectrum of 
     Mars, and its dependence on the Martian season, phase angle and 
     atmospheric dust content.

  -  To make complete spectral surveys using the SWS and LWS.  This will
     allow the determination of the concentrations of the most important 
     atmospheric species, and will establish a chemical inventory of the 
     atmospheric composition.


OBSERVATIONS SUMMARY
A full discussion of the scientific case is give in the CP programmes of 
the LWS Solar System SAG and the Mission Scientists.

The following is a summary of the astronomical objectives of each of
the observations tabulated below.  The expected S/N is typically 
several hundred. 


Obs. Seq. Nos.        Description
------------------    -----------------------------------------
1,3,5,7,9,11,17,22    Full LWS grating scans to be made at 
                      eight different epochs during the mission

2,4,6,8,10,12,18,23   Eight PHOT-S scans to be carried out at 
                      the same time the LWS scans

13                    One LWS full FP scan

14,15,16              These comprise one SWS full grating 
                      scan (Priority 1)

19,20,21              A second SWS full grating scan (Priority 2)

24                    CAM CVF scan 2.5-11.5 um