Photovoltaic arrays were used successfully to power the various instruments
for the Mars Pathfinder, To identify the type of the solar cell most suita
ble for Mars surface missions in the future, the spectral content of Mars's
solar radiation must first be determined, The response of photovoltaic cel
ls depends on the solar cell type and the wavelengths of the incident light
. The suspended dust particles of Mars's atmosphere affect the intensity an
d spectral content of the solar radiation reaching the planet's surface. Th
e Pathfinder employed four bandpass filters for measuring the atmospheric o
ptical depth during the course of the mission that lasted for about 80 sols
(Martian days). The central wavelengths of these filters were 450, 670, 88
3, and 989 nm, This paper deals with the analysis of the optical depth of t
he Martian atmosphere based on the Mars Pathfinder measurements and include
s 1) variation of the monochromatic optical depth with the time of the day,
2) variation of the monochromatic optical depth with sol for the duration
of the mission, 3) variation of the optical depth with wavelength, 4) trans
mittance of the direct beam with wavelength, and 5) solar cell response on
the Martian surface of the direct beam irradiance.