The following provides an overview of the program for each session during the workshop as well as a summary of the discussion period that followed each of the sessions.

8:30 Harry MacDonald

Welcome and Announcements

8:45 John Grant and Matthew Golombek

Overview of the Process of Site Selection

9:00 Mark Adler

MER Mission Overview

9:15 Steven Squyres

9:30 Joy Crisp

Expected Science Return from MER Missions

9:45 Ralph Roncoli

Mission Engineering Constraints

10:00 Matthew Golombek

Engineering Constraints and Remote Sensing

10:15 Timothy Parker

MOC Imaging During MGS Extended Mission

10:45 Jakosky B. M. * Golombek M. P. 

11:05 Tanaka K. L. * Crumpler L. S.  Gilmore M. S.  Noreen E.  Hare T. M.  Skinner J. A. 

11:25 Farmer J. * Nelson D.  Greeley R.  Kuzmin R. 

Summary of presentation: John Grant presented an overview of the landing site selection process and schedule and described the mechanisms for community input into the process.

Summary of presentation: the talk presented an overview of the MER mission including a description of the launch schedule, process for delivering the spacecraft to the surface of Mars, and the Athena payload carried by the rovers. The mission science requirements were summarized and a description of the EDL events (including how surface-detecting landing radar operates) and rover deployment from the landers was presented. Rover communications via X-band, two low-gain, and a back-up UHF antenna were also reviewed. Mission schedule was presented and mention was made of a mission CDR to occur sometime in the early Summer of 2001. Finally, an update on landing site engineering constraints was made with the caveat that further refinements will occur as the mission continues to be developed.

Summary of presentation: Began by stating that the success or failure of the mission is critically dependent on selection of the proper landing sites. Then proceeded to provide a detailed description of the mission science objectives. This description included statements that the landing sites need to show evidence for water, that the two sites should be different (thereby allowing two sets of hypotheses to be tested), and should take advantage of rover mobility. Made mention of the fact that there is a strong latitudinal dependence on power/thermal conditions that can impact science and landing ellipse size. Finally, an overview of the Athena payload was presented.

Summary of presentation: Provided an overview of the expected science return from the MER mission within the context of the "bare minimum" science floor versus the maximum return possible. Commented that the MER mission is still in preliminary design stages, but that the "snapshot" of the mission is close to what it will ultimately look like. Mission success criteria have been defined and were described and a presentation of the power and operational margins for the rovers at various landing latitudes was described. Bottom line: these margins should be enough to enable mission objectives to be met. For example, MER-A has more energy margin (~8%) and data return margin (~20%) than MER-B because the Earth and Mars are closer together during MER-A operations.

Summary of presentation: Provided a summary of the MER mission engineering constraints and briefly discussed the power and EDL issues described by Crisp and Adler, respectively. Provided some good news indicating that Earth tracking during the MER Mars landings is quite good for the proposed sites. Focused on unknowns and possible errors in landing site ellipses and mentioned that a TCM-5 (as described by M. Adler) will be required just before getting to Mars.

Discussion related to M. Golombek Presentation: This presentation discussed how the engineering requirements map into acceptable landing sites on Mars. A question was raised as to why MER-B might go to the Hematite site and MER-A to another site. The answer has to do with the southerly latitudes available to MER-A, where Valles Marineris and crater lake sites are located. The ellipse size is likely to change, although it will not decrease by a factor of two, so major changes in available landing sites are unlikely. No effort is presently planned to maintain a handbook on site selection, although a project plan does exist and landing site activities will be maintained on the two web sites. It was emphasized that the method used to triage the sites emphasizes science over engineering for the first time. Mention was maid of the Beagle landing site in Isidis Planitia and how it might affect MER site selection.

Discussion related to T. Parker Presentation: To conserve time Tim Parker did not give a presentation, although MOC imaging of landing sites was the topic of extended discussion later on during the meeting.

Discussion related to B. Jakosky and M. Golombek Presentation: This presentation stressed the different scales of observation available to inferring surface properties and the science that can be done at sites. One question mentioned that certain aeolian processes may operate at many if not all locations, but that the effectiveness of these processes at different locations is difficult to assess.

Discussion related to Tanaka et al. Presentation: This presentation discussed accessing Noachian material at a landing site. It was concluded that careful mapping is required to determine if Noachian age materials are actually present at a landing site. It was noted that the act of placing potential landing sites in smooth flat terrain likely biases away from Noachian materials and towards younger resurfaced areas, even where existing geologic maps indicate Noachian materials.

Discussion related to Farmer et al. Presentation: This presentation concerned exobiology priorities on landing site selection. It reported on discussions in the Astrobiology Institute, Mars Focus Group. As happened during the MEPAG deliberations, the NAI focus group was split over the proper programmatic emphasis (as presented in the MEPAG document) regarding the search for present versus past water (i.e., subsurface hydrosphere) versus the ancient rock record) and considered two approaches as co-priorities in astrobiological exploration. The Hematite site was highly regarded, with Gale crater just below in priority. The Gusev site in the north does not provide access to the southern delta and looks modified by aeolian activity. Apollonaris Chaos and Eos Chasma were next highest in priority. Both provide access to potential fluvial and hydrothermal environments. A question was raised on whether MOC images were consulted during the process. It was pointed out that all sites reviewed by the group included available MOC images which are archived with presentations on the CMEX and ASU astrobiology program websites. It was also asked whether the specific materials of interest could be sampled at the highlighted sites (e.g., in situ sedimentary layers at Gale Crater or a grab bag emphasizing lithologic diversity as would be possible at Eos Chasma). It was pointed out that each site offers different approaches to sampling, but that at this early stage in our reconnaissance of surface mineralogy that an emphasis on sampling in situ lithologic diversity should have priority.

1:00 Christensen P. R. * Bandfield J.  Hamilton V.  Ruff S  Morris R.  Lane M.  Malin M. 

1:20 Noreen E. * Tanaka K. L.  Chapman M. G. 

1:40 Allen C. C. * Westall F.  Schelble R. T. 

2:00 Hynek B. M. * Arvidson R. E.  Phillips R. J.  Seelos F. P. IV

2:20 Gilmore M. S. * Tanaka K. L. 

2:40 Barlow N. G. *

3:00 Duxbury T. C. * Ivanov A. B. 

3:20 Hartmann W. K. *

3:55–4:45 Jack Farmer and Philip Christensen

Discussion of Landing Site Priorities and the Hematite Site

General comments: It was generally agreed that we should cast the problem of site selection in terms of testable hypotheses. This is of "paramount importance" and "essential" for a successful program and should be followed when considering any site. Such an approach will provide a framework for making decisions about how to most effectively use the scientific payloads available, while helping to define the operational needs of the mission. In this context, the community needs to turn its attention to identifying "mature, testable hypotheses" for the MER missions.

At this juncture in the meeting, it was noted that all sites were still in the running and could be considered for MOC images. However, because the two sites selected need to be separated by more than 37^o, it is important to consider which sites that will be excluded by selecting the hematite site.

It was suggested that Terra Meridiani should be considered a candidate site for MER A, in order to free up other important sites that are only accessible to MER B. However, it was also noted that from an operational standpoint, MER A will be more capable (provide more science) than MER B. The generally smooth surface and greater homogeneity of the hematite site suggests that we won't need to travel as far, or perhaps conduct the mission for as long, to obtain acceptable results. The actual (as the crow flies) traverse distances expected will depend upon the terrane. On a smooth surface like that we expect to see at the hematite site, MER B may be able to traverse quite a long distance (100’s of meters) in the time available. From an operational standpoint, this favors using MER B for the hematite site, thereby freeing up MER A for operationally more challenging sites.

Important scientific questions to examine at the hematite site: What is the carrier of the specular hematite signature? Are other aqueous minerals present below the detection limit of TES? If so, what do they reveal about aqueous processes? What is the cratering history at the site and the precise nature of the exhumation process? What are the compositional features of the dark, low albedo units exposed there? What is the composition and state of preservation of the Noachian-aged units?

Arguments in favor of the hematite site: A wide range of disciplines (e.g. igneous petrologists to aeolian geomorphologists, to paleontologists) have expressed an interest in this site and for a variety of different scientific reasons. This suggests that a lot of good science will be possible at the site.

From the standpoint of following the (ancient) water, the specular hematite present at the Terra Meridiani site will probably not be the most interesting component present. TES can detect minerals down to ~5% abundance. Thus, we should think of the hematite as simply a proxy for other less abundant, but potentially more interesting aqueous minerals (e.g. Fe-carbonates, sulfates, etc.) that could be present below the detection limit of TES and which might provide even more valuable information about the nature of aqueous processes.

Even with the smooth surfaces suggested by MOC images, models predict there will most certainly be rocks available to sample. Even if we don't detect hematite (unlikely), we are still likely to find basalt, the most widespread rock type on the planet! In addition, we have not yet sampled a dark, low albedo surface on Mars- one of the most widespread and important units. The hematite site will provide direct access to this type of surface. It was noted that while Pathfinder provided our first look at rocks, it also accomplished a lot of good atmospheric science and aeolian process geomorphology that can be carried out almost anywhere on the surface.

The hematite site is the only site outside of the Isidis rim region to provide access to Noachian strata. There was discussion concerning whether the Hematite site was actually Noachian or a younger, possibly a Hesperian age deposit. It was pointed out that in the MOC images, we see evidence of subjacent units exposed almost everywhere. This suggests that access to older (probable Noachian) units will be possible over broad areas of the basin. Even limited sampling of the 2-3 visible units, plus crater ejecta within the basin could be quite important scientifically. In the exercise for '01 the landing ellipses were placed on smooth Hesperian units of the Isidis Rim where a variety of older materials would likely have been delivered by erosion from surrounding Noachian-aged massifs. In contrast, at Terra Meridiani, it appears that we can actually land on an exhumed Noachian-aged deposit. (It is noted that to accomplish this, a landing ellipse will need to be properly positioned to avoid landing on the younger, superjacent units.) Access to a recently exhumed older surface could be quite important given that older highland surfaces may have been deeply gardened by impacts. At the hematite site, the recent exhumation process should provide access to much fresher (ungardened) Noachian-aged materials.

Arguments against the hematite site: There is a danger in selecting sites on the basis of testable hypotheses because a boring null result could undermine overall Public interest and support of the Mars Program. Parts of the hematite basin are very flat (<1 m relief), giving the lowest MOLA pulse width of any place on the equator. However, the flattest (and safest) part of the basin could be quite homogenous and boring compared to a layered site. The limited roving distance of this mission suggests we may not be able to sample many important units (e.g. the bright crater rim materials).

The hematite site is not a typical highland surface. Rather it should be viewed as anomalous and unrepresentative of the planet. Given our need to understand the evolution of Mars as a planet, should we not select a more typical highland site? Also, given the difficulty of the relative dating surfaces using cratering ages, we should be careful about assuming we will be able to sample actual Noachian units at the hematite locality. And what if we land there and find only basalt? Can we really expect to learn anything important about the aqueous history of Mars by landing on basalt?

Arvidson R. E. 

Bishop J. L. 

Duxbury T. C. 

Anderson R.

Head J.

Fisk M. R. 

Gulick V. C.  Deardorff D. G.  Briggs G. A. 

Haldemann A.

Hare T. M.  Tanaka K. L.  Skinner J. A. 

Hauber E.  Neukum G.  Behnke T.  Jaumann R.  Pischel R.  Hoffmann H.  Oberst J.  HRSC Science Team  

Morris R. V.  Bell J. F. III

Urquhart M. L.  Gulick V. C. 

Arvidson, Results from FIDO Prototype Mars Rover Field Trials.

Discusses the use of the FIDO roving vehicle for rehearsing remote operations of a rover on Mars.

Bishop, Mineralogy Considerations for 2003 MER Site Selection and the Importance for Astrobiology.

Makes the case that at least one MER site should be an "average" Martian terrain to gather spectroscopic ground truth.

Duxbury, A New Era in Geodesy and Cartography: Implications for Landing Site Operation.

Describes the role of MOLA in reducing errors in position, spin rate, topography, and the planetary ephemeris on Mars by some two orders of magnitude.

Anderson, MER Site Characterization using MOC and MOLA Data.

Discusses the development of synergistic data sets for Mars by combining MOC, TES, and MOLA data.

Head, MOLA Data and Landing Site Selection.

Looks at the scale dependence of roughness on Mars using MOLA baselines, and correlations of the roughness with geologic units.

Fisk, Submarine Volcanic Landforms and Endolithic Microorganisms.

No presentation given.

Gulick et al., A Virtual Web Environment for Mars Landing Site Studies.

Illustrates computer models that correlate MOC and MOLA data "on the fly" allowing Web site users to interact immediately with the data.

Haldemann, GSSR Delay-Doppler Data for MER Landing Sites.

Illustrates locations of Earth-based delay-doppler data for Mars, including upcoming opportunities at the next opposition (mid-2001).

Hare et al. Planetary GIS on the Web for the MER 2003 Landers.

Demonstration of PIGWAD, a web-based GIS system for Mars. Announced that he is able to release modified versions of ArcView to users for free.

Huber et al. MER 2003 Operations Support and Landing Site Characterization by Mars Express HRSC/SRC Imaging.

Discusses what can be done for the evaluation of future landing sites using the imaging systems on the Mars Express mission.

Morris and Bell Hubble Space Telescope Visible to Near-IR Imaging and Spectroscopy of Mars in Support of Future Landing Site Selection.

Illustrates use of HST for mapping dust and mineralogy of Mars at ~20km spatial scales.

Urquhart and Gulick Lander Detection and Identification of Hydrothermal Deposits.

Discusses use of geochemical modeling (under constrained conditions) to investigate potential Martian hydrothermal systems. Terrestrial systems are used to validate model.

8:30 Jakosky B. M. * Mellon M. T.  Pelkey S. M. 

8:50 Golombek M. P. * Jakosky B. M.  Mellon M. T. 

9:05 Golombek M. P. *

9:15 Ruff S. W. * Christensen P. R. 

9:35 Kass D. M. * Schofield J. T. 

Jakosky et al. Physical Properties of Potential Mars Landing Sites from MGS TES-derived Thermal Inertia.

Golombek et al. Thermal Inertia of Rocks and Rock Populations and Implications for Landing Hazards on Mars.

Illustrated the effective thermal inertia of rock populations on Mars and Earth derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia.

Golombek Extreme Rock Distributions on Mars and Implications for Landing Site Safety.

Based on a sampling of MOC images, it appears that the abundance of large boulders (>3m) and boulder fields is relatively rare (~0.1% areally). Makes the case that if you can’t see rocks in high resolution images, there will probably be no landing site issues in terms of rock size.

Ruff and Christiansen A Spectrally-based Global Dust Cover Index for Mars from Thermal Emission Spectrometer.

Introduces a spectral dust cover index based on thermal IR spectra. The index shows a high degree of correlation with VISIR albedo, although exceptions do occur.

Kass and Schofield Atmospheric Constraints on Landing Site Selection.

Discusses the development of atmospheric models used in EDL models for assessment of landing safety.

10:10 Cabrol N. A. * Grin E. A. 

10:30 Bridges N. T. *

10:50 Newsom H. E. *

11:10 Nelson D. M. * Farmer J. D.  Greeley R.  Kuzmin R. O.  Klein H. P. 

11:30 De Hon R. A. *

11:50–12:05 Richard Morris and Bruce Jakosky

Landing sites that show putative geomorphic evidence for aqueous processes include so-called crater lakes (paleolakes in impact craters), outflow channels, and shorelines of lacustrine basins. These sites are consistent with the "follow the water" theme of the Mars exploration program and offer the opportunity to study the water and climate history of Mars and sedimentary deposits and the processes that formed them. Based on terrestrial experience, such sites are favored as sites to sample for evidence of extant and/or extinct life. Gusev and especially Gale Craters were the consensus landing sites for investigation of putative Martian paleolakes. These sites have dunes, layered deposits, and relatively safe areas for landing. Lower priority crater-lake sites include Meridiani Crater, Boeddicker Crater, and an unnamed crater (9.3S, 209.5). A site in Durius Valles (outflow channel) was also discussed and given a lower priority.

1:20 Crumpler L. S. * Tanaka K. L.  Hare T. M. 

1:40 Gulick V. C. *

2:00 McEwen A. * Lanagan P.  Beyer R.  Keszthelyi L.  Burr D. 

2:35 Weitz C. M. * Parker T. J.  Anderson F. S. 

2:55 Mangold N. * Costard F.  Masson P.  Peulvast J.-P. 

3:15 Kuzmin R. O.  Greeley R. * Nelson D. M.  Farmer J. D.  Klein H. P. 

3:35 Rice J. W. Jr.*

3:55-4:15 Ginny Gulick and Roger Phillips

Summary Discussion

We should go to a place that we are "sure" has an aqueous origin over ~100% of ellipse to learn the "signature" of an aqueous site. Then we would be able to better recognize aqueous sites elsewhere and at the site learn about water processes on Mars. Landing site evaluations should focus on a few sites and raise confidence that they really are water sites over much of the ellipse. We must be able to access an aqueous environment no matter where the rover lands in the ellipse.

The outflow channels, some of Valles Marineris, Apollonaris, and Isidis offer grab bag samples that may be difficult to place in a geologic context. Sampling crater ejecta may also provide information about the subsurface, but may also be difficult to place in a geologic context.

Synopsis: The non-hematite site should be one that we are 100% confident has an aqueous origin, and aqueous over 100% of the landing ellipse, so that we are 100% confident that an aqueous environment can be sampled. There was less enthusiasm for a "grab bag" site because of the difficulty of placing the results in a geologic context.

4:15-6:15 Mike Carr and George McGill

A total of 32 high-priority sites for Mars 2003 landers/rovers were considered by those attending the workshop. These 32 sites were classified into three groups: 1) highest priority, to be imaged by MOC using non-nadir look angles if necessary; 2) sites of opportunity, to be imaged by MOC with normal nadir-looking geometry as opportunity arises; 3) lowest priority, no special effort to collect MOC images is recommended. A concerted effort was made to include in the highest priority list sites with as varied geology and topography as possible.

Concern was expressed that many sites with interesting geology might prove disappointing if the features of interest are beyond roving range. Sites with widely distributed or multiple targets, such as the hematite sites, Melas Chasma site, or a "grab bag site" such as Eos Chasma, are most likely to avoid this problem.

The hematite region was by far the most strongly supported candidate for a landing site. Because this is an extensive region it is possible to define many potential landing sites. Three specific sites within this region are among those on the highest priority list to permit some choice related to interesting geology or safety.

It is understood at this time that no sites have actually been selected. The next phase is to collect the additional data needed to assess both the science and the safety of all sites under consideration. These additional data include extensive coverage by MOC images, but also other input, such as analysis of MOLA pulse widths. Only after these data are in hand will it be possible to select the final sites. Likewise, no decision has been reached concerning which lander (MER-A or MER-B) would be assigned to any given site unless only one is possible within latitude constraints.

The classification of sites by the workshop participants is as follows:

HIGHEST PRIORITY (9 sites)

Hematite region TM10A/20B, TM21B, TM9A/19B

Gale crater EP82A

Gusev crater New site in the southern part of the crater

Valles Marineris (Melas Chasma) VM53A

Valles Marineris outflow (Eos Chasma) VM41A

Elysium (Cerberus plains) EP49B

Isidis (southern edge) IP85A/98B

SITES OF OPPORTUNITY (17 sites)

Hematite region TM11A/22B, TM12A/23B

Meridiani crater TM15A, TM16A

Unnamed crater EP69A

Boeddicker crater EP64A

Gusev EP55A

Apollinaris New Site at roughly 9.5S, 190.2W

Durius Vallis EP56A

Valles Marineris VM47A, VM48A, VM44A

Valles Marineris outflow VM42A, VM37A

Elysium EP74A

Isidis IP84A/96B

Cratered terrain TM13A/24B

ELIMINATED FROM CONSIDERATION (7 sites)

Valles Marineris outflow CP35B

Elysium EP71A, EP62B, EP77A, EP19B, EP61B, EP52B/68A

The First Mars 2003 Landing Site Workshop held January 24th and 25th, 2001 at Ames Research Center was just completed. A general consensus was reached on the highest priority landing sites. Three lists of

sites were agreed on. The first list is the highest priority sites that will be targeted by nadir and off nadir MOC images. The second list is medium priority sites that will be targeted by nadir MOC images only, when they become available. The third list is of sites that are being eliminated from further consideration. The lists include the site name, approximate ellipse center (latitude, longitude), elevation and geologic unit. Note that the ellipse center will shift slightly from these as ellipses with the new sizes are placed in these locations. In addition, the site in the southern part of Gusev crater has yet to be sited, the Apollinaris and Elysium sites are approximate at this time. New ellipse maps will be prepared and distributed shortly. If you see any errors in sites or ellipse locations, please let us know. Feel free to distribute this list.

Hematite Sites

1)

TM10A 2.2S 6.6 -1.7 Npl2

TM20B 2.3S 6.2 -1.3 Npl2

2)

TM21B 2.5S 3.3 -1.3 Npl2

3

TM9A 1.2S 5.6 -1.3 Npl2

TM19B 1.2S 5.3 -1.3 Npl2

Crater Gale

EP82A 5.8S 222.4 -4.5 S

Crater Gusev

New site in south of Gusev crater to be selected. Will be roughly at

15.5S, 184.5W.

Valles Marineris, Melas Chasma

VM53A 8.8S 77.7 -3.5 Avf

Valles Marineris Outflow at Eastern End

VM41A 14.0S 42.0 -4.0 Hch

Elysium Outflow

EP49B 7.4N 205.6 -3.0 Ael1

Isidis

IP85A 4.5N 271.9 -4.5 Aps

IP98B 4.7N 276.4 -4.0 Aps

Hematite

TM22B 3.2S 7.1 -1.7 Npl2

TM11A 3.4S 6.9 -1.6 Npl2

TM23B 3.4S 3.1 -1.4 Npl2

TM12A 3.6S 2.9 -1.3 Npl2

Other Crater Lakes

Meridiani Crater

TM15A 8.6S 6.7 -1.9 S

TM16A 9.4S 6.6 -1.9 S

Un-named Crater

EP69A 9.3S 209.5 -1.7 Npl1

Boeddicker

EP64A 14.8S 197.5 -2.1 Npl1

Duirus Valles

EP56A 14.6S 188.1 -1.6 Npl1

Gusev

EP55A 14.2S 184.8 -1.9 Hch

Valles Marineris

VM44A 13.1S 62.5 -4.5 Avf

VM47A 6.2S 70.1 -5.0 Avf

VM48A 7.1S 72.5 -5.0 Avf

Valles Marineris Outflow

VM37A 11.1S 37.9 -4.0 Hch

VM42A 7.7S 50.7 -4.5 Avf

Elysium

EP74A 4.2N 216.6 -3.5 Achu

Apollinaris

New Site at roughly 9.5S, 190.2W

Isidis

IP84A 4.5N 271.9 -4.5 Aps

IP96B 4.6N 272.3 -4.5 Aps

Cratered Terrain

TM13A 2.9S 10.5 -1.8 Hr

TM24B 2.8S 10.1 -1.8 Hr

Vallis Marineris Outflow

CP35B

Elysium Planitia

EP52B/EP68A

EP71A

EP62B

EP77A

EP19B

EP61B