Landing Site Selection

The MSL landing site will profoundly influence the nature and quality of the scientific return from the mission, as well as the pace and strategy for surface operations. An ideal landing site would: i) contain evidence suggestive of a past or present habitable environment; ii) meet or exceed all engineering and safety constraints; and iii) allow acceptable operational performance. A corollary to the first criterion is that the evidence for habitability, whether geological, chemical, or biological, would be preserved for, accessible to, and interpretable by the MSL payload. Operational performance can be impacted by terrain (e.g., more obstacles to navigate through) or temperatures (e.g., colder daytime temperatures result in energy being diverted to heaters).

The selection of the MSL landing site is informed through a series of community-led, open workshops that have occurred in parallel with the design and development of the spacecraft. The workshops are organized by a NASA-appointed Landing Site Steering Committee, co-chaired by Dr. John Grant (Smithsonian Institution) and Dr. Matthew Golombek (JPL). Workshops in June 2006, October 2007, and September 2008 considered over fifty sites, narrowing the list of candidate sites to four. The down-selections have been based on many factors including their scientific relevance, assessment against surface and atmospheric safety constraints, and programmatic considerations (e.g., inclusion of a very safe site). The final site and backup will be selected in 2010-11 after additional community workshops and subsequent analyses by the MSL Project, science teams, and NASA officials. The selecting official is the NASA Associate Administrator for the Science Mission Directorate.

One of the design goals of the MSL mission is to provide access to more of Mars´ surface by removing or broadening the constraints present on previous missions and by not tailoring the design to any specific site or set of environmental conditions. Such a design also allows the final site selection to occur later in the process, providing more time to incorporate data and discoveries from the missions that precede MSL. Relative to previous landers, MSL can target a site with smaller uncertainty (~20 km) and can land and operate over a wider range of latitudes (i.e., thermal environments) and elevations. In addition, the rover´s driving capability is similar to its landing uncertainty, meaning that the rover can drive outside of its "error ellipse." This factor allows the consideration of scientific targets that may be too hazardous for landing, but can be accessed by roving from an adjacent safe area. Such landing sites are called "go-to sites." A trade-off in selecting a go-to site is that a large fraction of the primary mission (perhaps half) might be required to reach the target.

A list of the current candidate landing sites can be found below. These finalist sites have passed preliminary checks against engineering and safety criteria, though data acquisition and analyses are ongoing. From a scientific standpoint, sites with mineralogical (phyllosilicates or sulfates) and/or geological evidence (depositional fans, fluvial systems) for past aqueous activity, as detected from orbit, are thought to be the most relevant for the MSL science objectives and payload. Landing will occur in the early afternoon, in late northern Summer on Mars.

Landing site safety criteria, EDL capabilities, and ellipse parameters are described in the first web link below. The links also contain the presentations from the community workshops, and catalogs of the data sets from various orbital experiments that are relevant to site studies.

Marsoweb MSL Landing Site Web Site
USGS MSL Landing Site Web Site