Dear Colleague:

The second landing site workshop for the 2009 Mars Science Laboratory
(MSL) will be held at the Courtyard Marriott in Old Town Pasadena, CA,
on October 23-25, 2007. The format will include oral presentations and
general discussion of the proposed landing sites. Each site will be
represented by a single speaker or science spokesperson at the workshop.
Presentations are also solicited on the safety of the landing sites and
how well they conform to the engineering requirements.

The primary goal of the second workshop will be to evaluate the 33 sites
that emerged from the first workshop as well as any new sites proposed
within the framework provided by new Mars Reconnaissance Orbiter (MRO)
data for the sites, the science requirements of the MSL mission, and a
better understanding of the MSL engineering requirements and the safety
of the landing sites relative to these requirements. ***Presenters at
the workshop must*** ***make a comprehensive, persuasive talk on why a
site is the right one for the MSL mission and payload, including an
assessment of the engineering criteria (where possible) so that each
site can be comprehensively and fairly assessed.***

The MSL project has recognized the need for a strategy to ensure that
the science value of the landing site is not unnecessarily compromised
when faced with late-breaking threats to EDL, degradation in rover
surface performance, or failure of high-priority sites to meet the
nominal engineering constraints. Sites presently known to meet a higher
safety standard can be considered \"safe havens\" and are sites that can
serve as backups or conservative selections while still maintaining high
value science. Accordingly, we are specifically requesting the proposal
of \"safe haven\" sites at the second workshop which must meet a more
restrictive set of engineering constraints (see Section 4 of the User\'s
Guide, <http://marsoweb.nas.nasa.gov/landingsites/> and
<http://webgis.wr.usgs.gov/msl>) . Safe havens have larger landing
ellipses, so these sites cannot be "go to" sites and instead must have
high science value targets within the ellipse. Ideally, \"safe haven\"
ellipses would be identified for all primary science sites, in addition
to, or replacing, the current ellipses. If safe haven ellipses cannot be
found near a primary science site, the project may have to carry the
best available safe haven ellipse at a similar latitude band to the
primary (the exact bands are TBD depending upon final Mars arrival
constraints) as a backup option. In the latter case, the scientific
value of the available safe haven may influence the selectability of the
primary site.

Persons wishing to make presentations at the workshop should consult the
"Information to Presenters" on the web sites. Persons wishing to propose
a new landing site and/or "safe haven" landing sites must consult
mission science and engineering requirements (see the User's Guide at
<http://marsoweb.nas.nasa.gov/landingsites/> and
<http://webgis.wr.usgs.gov/msl>). A short summary of any new sites
should be provided to both John Grant and Matt Golombek (co-chairs of
Landing Site Steering Committee) no later than September 21, 2007. The
third announcement for the second landing site workshop will include the
scheduled talks and be distributed in early October 2007.

Based upon revision of the MSL landing site selection schedule, we
expect the list of sites under consideration to be narrowed to
approximately five at the end of the second workshop. These sites will
then be considered in more detail by the MSL Project, Mars Program, and
the Science Community with the expectation that additional orbital data
will be obtained. Future workshops are planned that would further narrow
the list of sites under consideration to a recommended landing site zone
and (eventually) precise landing ellipse.

A number of websites provide access to more information on the MSL
mission, relevant engineering requirements, landing site selection
process, and available data for the proposed sites. Please note there
are a number of important changes to the engineering constraints since
the first workshop that include a decrease in the latitude range and
altitude to between +/-45^0^ latitude and below 1 km MOLA-derived
elevation, respectively. Websites where this information, a description
of the site selection process, and outcomes of the first workshop are
posted are:

<http://marsoweb.nas.nasa.gov/landingsites/>

<http://webgis.wr.usgs.gov/msl>

Additional images and derived data products relevant to the MSL site
selection process can be viewed at:

<http://marsoweb.nas.nasa.gov/HiRISE/hirise_images/>
[(HiRISE)]{.underline}

[http://themis.asu.edu](http://themis.asu.edu/) (THEMIS daytime,
nighttime IR, VIS, and thermal inertia mosaics)

[[http://themis.asu.edu/landingsites/]{.underline}](http://themis.asu.edu/landingsites/)
(Decorrelation stretched THEMIS daytime mosaics)

<http://www.msss.com/mars_images/moc/guest/> (MOC)

[[ftp://psa.esac.esa.int/pub/mirror/MARS-EXPRESS/HRSC/]{.underline}](ftp://psa.esac.esa.int/pub/mirror/MARS-EXPRESS/HRSC/)
(HRSC)

Descriptions of the MSL mission and a summary of NASA's Mars exploration
strategy are available at:

<http://mars.jpl.nasa.gov/msl/overview>

<http://mars.jpl.nasa.gov/mep/mslides/index.html>

http://mepag.jpl.nasa.gov/reports/index.html.

All members of the scientific community are encouraged to participate in
the MSL site selection process, as input from the science community is
critical to identification of optimal landing sites for the MSL. We look
forward to your continued involvement in these activities!

Sincerely,

John Grant and Matt Golombek

Co-Chairs, Mars Landing Site Steering Committee