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Abstract:
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Almost 40 years after the rst successful landing on Mars, exploration of its surface
still presents enormous scienti c and technological challenge. This particularly holds
for the Mars southern highlands, which cover large part of the southern hemisphere
where no successful landings have been achieved up to date. On the other hand, in
the northern lowlands, which spans most of the northern hemisphere, there has been
7 successful landings. This difference is consequence of the speci c topography of the
Martian surface due to so-called global or hemispheric dichotomy, which is a unique
characteristic in the Solar system. Due to the difference in the surface elevations, the
vehicle trying to land on the southern highlands has thinner layer of the atmosphere
that can use for the dissipation of its kinetic energy. Since the vehicles from the
interplanetary trajectories enter the Martian atmosphere with hyperbolic velocities,
their kinetic energy is extremely large and possibility for its dissipation through
the interaction with the atmosphere has crucial importance for the landing on the
locations with high elevations.
Beside the differences in topography between northern lowlands and southern
highlands, there is also a big difference in the number of impact craters between these
two regions. This fact indicates that the southern highlands are several billion years
older than the northern lowlands, which were exposed to strong volcanic activity in
the relatively recent past. Such huge difference in age is strong motivation to explore
the entire surface of Mars in order to understand its complex geological evolution. In
addition, large number of open basins discovered in the southern highlands suggests
that these regions could contain liquid water in the past, which is one of the most
important reasons for exploring these sites.
The main objective of this dissertation is to determine whether it is possible to
land on the southern highlands, without advancing the technology which was used
for the previous landings on Mars. Since the atmosphere of Mars is extremely dy-
namic due to high sensitivity to insolation, the parameters in uencing the process
of landing, especially density and temperature, have extremely large variations on
the daily and annual scale. In that sense, it is necessary to accurately model the
in uence of the most important parameters, such as the orbital position of Mars and
local true solar time, in order to determine the optimal conditions for landing. For
this purpose, a numerical algorithm for determination of the trajectory of a vehicle
with arbitrary aerodynamic characteristics, moving through the atmosphere with ar-
bitrary vertical and horizontal pro les, under the in uence of arbitrary gravitational
eld, has been developed. Using this algorithm, large number of atmospheric tra-
jectories was simulated which enabled determination of the possibilities and optimal
conditions for landing on the southern highlands. |