Landing Site
Targeting Diacria
Selection Process
Step-by-Step Results
Top Six Sites
Previous Landings
Site Terminology
Sources
Landing Site
Landing Site Selection
The process of choosing a landing site was divided into several manageable parts.
Part One: Qualitative Site Exclusion:Using NASA's comprehensive Center for Mars Exploration site, we have examined each distinct area of the planet's surface. After reading descriptions of all potential landing sites, we were able to eliminate nearly two-thirds of the landing sites (94 sites) as marginally conducive to exobiology or worse. (See Step-by-Step Results, to the left.)
Part Two: Cluster Identification
We mapped each remaining landing site on the surface of Mars and looked for clusters of sites. Landing sites that are clustered offer a good chance of success, since one landing can have access to multiple exobiology test sites. The major clusters are as follows (from North to South):
-Alba Patera West 46°N, 138°W-Utopia Region 45°N, 251°W-Labeatis and Kasei 27°N, 82°W-Chryse Planitia 25°N, 50°W-Candor Chasma and Region 6°S, 73°W-Mangala Valles East 6°S, 150°W-Sinus Sabaeus and Schiaparelli 6°S, 335°W-Mangala West/Memnonia 14°S, 175°W-Gusev Region 15°S, 185°W-Parana- Samara-Valles 22°S, 12°W-Hellas Region 40°S, 290°WIt is curious to note the preponderance of sites within the 6°S-14°S range. It is also worth noting that numerous equally good sites are not clustered with any other exobiology test sites, and therefore do not appear in the above list.
Part Three: Terrain Diversity Rating
Since a successful mission will involve successful tests, the best way to ensure mission success is to ensure that the astronauts have a wide variety of tests to perform on the surface. Testing options are directly related to the types of geological terrain available to the astronauts, so the ratings of landing locations can be based on the number of types of terrain nearby. We are looking for:
-Ice-Geothermal Features-Fluvial Sediment-Cliffside Sediment Layers-Impact Crater EjectaPart Four: Exobiological Potential Rating
We returned to the CMEX web site and compared the list of our most diverse landing sites to their list of sites with the most potential for exobiology. We found a close correlation, as we hoped we would. This meant that our diversity rating was meaningful according to NASA defintions.
Part Five: Picking the Best Handful
Although a great many of the sites we had left after step four looked good to us, we were able to eliminate all but six of those sites after learning that the rover range had been reduced to 75km of surface travel (to accomodate power and food limitations). This reduction in rover range eliminated any clustered potential of some sites, so we were left with this handful of outstanding sites:
-Kasei Valles North-Maja Valles-Gusev Crater-Ares-Diacria Southeast-Phaethontis North-CentralThese sites are "outstanding" because of the diversity of their terrain (four checks or more), or, in the case of Gusev, because of the amount of data available on the site.
Part Six: Comparing Pros and Cons
We hoped that the easiest way to eliminate five of the six remaining sites would be to categorize pros and cons. This was done in tabular form, but the choice did not then become straightforward. A lot of information was available about Gusev Crater, and the other five all appeared to be very good landing sites. Had we the option of exploring all six sites, we would do this. We cannot do this with a single mission, however, so we decided to pick the one site that contained its diversity in a compact region.
Final Decision: Diacria Southeast
We decided to land the mission at the Diacra Southeast crater, visible at 39.5°N, 135.5°W. The landing ellipse (20km north to south, 30km east to west) will fall inside the crater along the northern rim. From this position, the astronauts will have the best chance of getting to: the top of the crater rim for the cliff hanger experiments; to the northwest portion of the crater floor, which is suspected to be entirely fluvial sediment; to the foot of the deltas at the eastern end of the crater. There is a small chance for surface ice or geothermal vent structures in this location.
