As a participant at the Mars landing site Workshop held at NASA Ames this past January, your participation in the "next step" of the landing site selection process is solicited.
An Overview of the Process to Date -
As you are aware, the process of selecting landing sites for the twin MER rovers began with over 185 potential sites under consideration. The science community initially prioritized these sites on the basis of presentations made at the Ames workshop: 26 sites were recommended for further consideration based on preliminary assessment of science potential and landing safety sites (33 ellipses when counting some overlapping sites potentially accessible by either MER A or B).
Of the 26 sites emerging from the Ames workshop, 17 sites (21 ellipses) were identified as moderately high priority and recommended for MOC imaging during nadir opportunities (hereafter referred to as Nadir Sites). An additional 9 sites (12 ellipses) were identified as highest priority and recommended for MOC imaging via ROTO observations (hereafter referred to as ROTO sites). MOC images obtained of all of these sites are posted regularly at both the Ames and USGS websites and community review and comment is encouraged.
Evaluation of MOC images and other data has identified features in a few of the sites (e.g., landing/egress hazards or that might compromise science potential) that resulted in proposals to either shift some landing site ellipses slightly or to no longer consider a few sites as viable. Each of these proposals was reviewed and discussed by the NASA-appointed Landing Site Steering Committee. Based on unanimous opinion and NASA concurrence, the location of two ROTO ellipses (Melas Chasma and Gusev Crater) has been slightly shifted and one ROTO site (in Elysium) and 7 Nadir ellipses have been eliminated from consideration. Elimination of these sites was based on expected cold temperatures inferred from albedo and thermal inertia data (see Ames and USGS landing site websites) or hazardous surface relief and slopes.
The Next Step -
The next stage of the process will involve a comprehensive evaluation of the highest priority sites remaining under consideration in order to arrive at consensus regarding their relative priority. More specifically, the mission requirement of down-selecting to two broad landing regions (10 X 15 degrees) by early Spring 2002 necessitates discussion of which remaining sites are of the highest priority, whether some sites should no longer be considered, or if others should be elevated in priority. Your input will comprise a critical element of these discussions.
Evaluation and "reprioritization" of the sites will take place at Cornell University, in Ithaca, NY, from September 17-18th, 2001. Because of the focus being placed on consideration of sites already assessed as high priority by the science community, the format of this meeting will only include presentations related to characterization and science potential of those sites. Presentations on alternate or new sites will not be possible during this meeting. A major outcome of the meeting will be a shortened list of sites (four) which can be recommended to the JPL project, science team, and NASA Headquarters for detailed evaluation in time for selection of the two landing regions at a workshop in March of 2002.
In addition to the four primary sites, we will maintain a limited number of sites as backups in the event that any safety or science problems are identified with the primary sites.
NASA Headquarters has endorsed this plan and has asked the Landing Site Steering Committee to enlist community input and lead the process of recommending the highest priority sites. To accomplish this, the September meeting at Cornell will include the Landing Sites Steering Committee, members of the science community, key MER project/science team personnel, and members of the Athena science team. The landing site meeting will immediately precede an Athena Science Team Meeting.
An Invitation to Participate -
The format for science community input will include oral presentations by a representative for each of the highest priority ROTO sites emerging from the Ames workshop in January (e.g., Hematite site, Gusev Crater, Gale Crater, Valles Marineris, Melas Chasma, and southern Isidis Basin). The science spokesperson for each of the highest priority sites will be asked to present a summary of the science potential of the site (relative to the MER mission science objectives) at the September meeting in Ithaca.
We encourage input from the broader science community regarding the relative merits of the sites (via website and e-mail submission of comments) and will forward relevant materials to the spokesperson for each site. Members of the science community are welcome to attend and participate in the September meeting discussions at Cornell. Presentations, however, will be limited as noted above. It will not be possible to reimburse you for travel expenses related to the meeting.
In addition to presentations by members of the community on the science potential of the sites, persons involved in Mars characterization studies are also being invited to attend. These studies will relate to the surface characteristics and safety of the sites under consideration. Presentations on surface characteristics and safety considerations do not need to be coordinated with the presentation by the "landing site spokesperson". The combination of science input and results of characterization efforts will provide the basis for arriving at consensus on which four sites should remain under consideration for detailed study for the 2003 MER rovers and which sites should be maintained as backups.
Future Activities -
The next step in the process will take place during an open landing site workshop to be held in March or April, 2002, and will focus on two activities. The first involves down selection of the two landing regions (10° by 15° landing regions) for the 2003 Mars Exploration Rovers and continued scrutiny of specific landing ellipses within these regions. The second activity will begin the process of identifying possible landing sites for the Mars 2007 mission. Presentations related to both of these activities will be solicited in a future announcement from the science community as well as individuals involved in Mars mission planning and surface characterization studies. We hope that you will plan to attend and participate in this meeting as well.
We recognize that your input is critical to the success of the landing site selection process. Hence, we ask that you e-mail John Grant (grantj@nasm.si.edu) and Matt Golombek (mgolombek@jpl.nasa.gov) September 1st, 2001, regarding input to the relative science merits of the high priority landing sites and whether you will attend the meeting in Ithaca.
Sincerely,
John Grant and Matt Golombek
Co-Chairs, Mars Landing Site Steering Committee