Dear Colleague:

As a participant and/or presenter at the first MSL landing site workshop
in 2006, your participation in the "next step" of the landing site
selection process is solicited. 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 and associated science and engineering requirements and
the safety of the landing sites relative to these 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. ***We expect
that approximately five sites will remain under consideration after the
second workshop. Hence, it is critical that presenters make a
comprehensive, persuasive talk on why a site is the right one for the
MSL mission and payload and include discussion (where possible) of the
engineering criteria so that each site can be comprehensively and fairly
considered***. An update of these requirements is included in the
updated User\'s Guide, attached and at:
\<http://marsoweb.nas.nasa.gov/landingsites/\>http://marsoweb.nas.nasa.gov/landingsites/
and \<http://webgis.wr.usgs.gov/msl\>http://webgis.wr.usgs.gov/msl.

***Because of the need to focus discussion, each site will be
represented at the workshop by a single speaker/science spokesperson at
the workshop.*** A list of the sites and the people proposing them at
the first workshop is attached. For sites proposed by multiple
individuals, we ask that you communicate with one another and identify a
single spokesperson for the site at the second workshop. Although there
will be only one speaker for each site at the workshop, the
participation of other interested individuals will help to ensure
comprehensive presentations of each site and is expected and encouraged.

We ask that you confirm the identity of the spokesperson for each site
or let us know if you wish to have a site taken off the list under
consideration no later than September 21, 2007. If we do not hear from
site representatives by that time, we will identify/confirm site
spokespersons and or remove sites from further consideration. We regret
that it will not be possible to reimburse you for travel expenses
related to the workshop.

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/\>http://marsoweb.nas.nasa.gov/landingsites/
and \<http://webgis.wr.usgs.gov/msl\>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 propose a new landing site and/or "safe haven"
landing sites must adhere to the science and engineering requirements
described in the User's Guide (see
\<http://marsoweb.nas.nasa.gov/landingsites/\>http://marsoweb.nas.nasa.gov/landingsites/
and \<http://webgis.wr.usgs.gov/msl\>http://webgis.wr.usgs.gov/msl),
make a comprehensive and compelling case for the science and safety of
the site, and provide a short summary of the new sites to both John
Grant and Matt Golombek (co-chairs of Landing Site Steering Committee)
no later than September 21, 2007.

Presentations at the second workshop will be evaluated based on a number
of relevant science and engineering criteria (see attached list) to
assist in narrowing the list of sites Additional presentations that
focus on the safety of the landing sites and how well they adhere to the
engineering requirements are also solicited and these talks are not
subject to the one speaker/science spokesperson per site requirement.
Persons wishing to make presentations on the safety of landing sites
must provide a short summary of their presentations 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.

Sites emerging from the second workshop will 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.

We value the input of the science community in identification of the
optimal landing site for MSL. Please feel free to contact either of us
if you have any questions regarding the site selection process or plans
for the second workshop. We look forward to your continued involvement
in these activities!

Sincerely,

John Grant and Matt Golombek

Co-Chairs, Mars Landing Site Steering Committee