Possibilities and optimization of landing on the southern hemisphere of Mars.

[ D. Marčeta]

[11], 177 listova

Astronomija / Astronomy

Skoro 40 godina nakon prvog uspesnog sletanja na Mars, istrazivanje njegove povrsine pomocu kosmickih letelica i dalje predstavlja ogroman naucni i tehnoloski izazov. Ovo se pre svega odnosi na Marsove juzne visoravni, koje se protezu na velikom delu njegove juzne hemisfere, na koje do sada nije izvrseno nijedno uspesno sletanje. Sa druge strane, na severne nizije, koje se prostiru na velikom delu severne hemisfere, do sada je izvrseno 7 uspesnih sletanja. Ova razlika je posledica specicne topograje Marsove povrsine usled takozvane globalne ili hemisfericne dihotomije Marsa, koja predstavlja jedinstvenu karakteristiku u Suncevom sistemu. Usled razlike u elevaci- jama povrsine, letelice koje slecu na juzne visoravni imaju na raspolaganju tanji sloj atmosfere koji mogu da iskoriste za disipaciju kineticke energije. Buduci da letelice sa interplanetarnih putanja ulaze u atmosferu Marsa hiperbolickim brzinama, nji- hova kineticka energija je veoma velika i mogucnost da se ona smanji kroz interakciju sa atmosferom je od odlucujuceg znacaja za sletanje na lokacije sa velikom elevaci- jom. Osim topografske razlike izmed-u severnih nizija i juznih visoravni, postoji i velika razlika u broju udarnih kratera izmed-u ovih oblasti, sto ukazuje na veliku razliku u starosti. Procenjuje se da su juzne visoravni nekoliko milijardi godina starije nego severne nizije, koje su u relativno bliskoj proslosti bile izlozene snaznoj vulkanskoj aktivnosti. Ovako velika razlika u starosti predstavlja motivaciju za istrazivanje celokupne povrsine Marsa u cilju razumevanja njegove slozene geoloske evolucije. Osim toga, veliki broj otvorenih basena, koji su otkriveni na juznim visoravnima, ukazuju na to da su ove regije u proslosti mogle biti prekrivene tecnom vodom, sto predstavlja jedan od najznacajnijih razloga za istrazivanje ovih lokacija...

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...

Mars, atmosfera, sletanje

Mars, atmosphere, landing

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