PIO/SI(I271 • - / i _! t , i "- ? I( ' [ ! MARS sURVEYOR PROJECT LANDING SITE ACTIVITIES ['t: c_'tli _tetection Virginia C. Gulick, NASA-Ames Research Center, MS 245-3, Moffett Field, CA 94035; [email protected]; Geoffrey Briggs, NASA-Ames Research Center, MS 239-20, Moffett l high Field, CA 94035; R. Stephen Saunders, Martha Gilmore, Jet Propulsion Laboratory, MS 183- _aergy 335, 4800 Oak Grove Drive, Pasadena, CA 91109; and Larry Soderbiom US Geological Survey 2255 N. Gemini Drive Flagstaff, AZ 86001. _,esub,, l The Mars Surveyor Program --now a cooperative program led by NASA and CNES along dty is ,ith other international partners -- is underway. It has the primary science objective of furthering action understanding of the biological potential and possible biological history of Mars and has the much amaplementary objective of improving our understanding of martian climate evolution and planetary ,surface i_ory. The missions will develop technology and acquire data necessary for eventual human _ploration. Launches of orbiters, landers and rovers will take place in 2001 and in 2003; in 2005 a the _4nplete system will be launched capable of returning samples to Earth by 2008. A key aspect of the program is the selection of landing sites. This abstract 1) reports on the flatusof the landing site selection process that begins with the 2001 lander mission and 2) outlines I_ opportunities for the Mars community to provide input into the landing site selection process. IKkground Nominally, each mission includes at least a lander and a rover, both instrumented. Currently, fie 2001 mission (http://mars.jpl.nasa.gov/2001/index.html) includes a lander carrying a package to _ll_asure the surface radiation environment and to extract oxygen from the atmosphere along imtrurnents to be flown on the 2003 Athena rover: PanCam, a panoramic camera, MiniTES, an i_ared spectrometer, and a Mossbauer spectrometer. The lander will have a robotic arm and arm t_aneraadapted from the Mars Surveyor '98 mission. The lander will also carry a descent imager to I_port the 2001 rover, named Marie Curie, which will be essentially the same as Pathfinder's and Sojourner rover but with improved, calibrated APXS. The 2003 rover, named Athena, will be larger, more sophisticated, more capable, and have I_ ability to aquire surface materials for launch to, and to cache in, Mars orbit. The 2005 rover will anear copy of Athena and its collected samples will be launched to Mars orbit for recovery along the the Athena samples and transfer back to Earth The Athena rover science goal is to "determine the geologic and climatic history of a site in I_ ancient highlands where conditions may have been favorable to the preservation of evidence of Possiblepre-biotic or biotic processes". To do so the rover objective is to identify, collect, and store e g mrtian rocks and soils that have the highest possible chance of preserving evidence of ancient conditions. Site Engineering Constraints Three mission aspects drive the landing site selection: (1) The ability of the lander to reach site; (2) the safety of the landing site; and (3) the scientific characteristics of the landing The engineering constraints (1 and 2) are set by orbital mechanics, by the capabilities of the rack entry and descent system, and by the characteristics of the rocky martian surface. Table I the current engineering constraints for the 2001 mission. The size of the landing ellipse the rover mobility (- lkm for Athena, 10's of meters for Marie Curie) control how localized the track region may be if it is to be successfully sampled. An areally-extensive target, for example, the probability that the lander will land on or near the target and minimizes the required a traverse distance. A precision landing system, if developed, will minimize the landing ellipse greatly help in the investigation of sites that are small in areal extent. Landing Site Selection Procedure i__il The responsibility for the landing site selection rests with the Surveyor Project Otfice" at Jpl2_::'v_: and the Project Scientists involved. For the 2001 mission the Project Scientist has appointed a _;'!_"i_ Steering Committee to assess and recommend candidate sites. The Project Scientist is supported by astrobiologists at NASA's Ames Research Center through its Center for Mars Exploration .z • (CMEX) and by the USGS's Astrogeoiogy Branch in Flagstaff, Arizona. CMEX is responsible providing an interface with the general Mars science community and assisting in the overall coordination of the landing site selection process. To this end CMEX will host workshops and provide a web site and other support to ensure the participation of the general Mars community. US Geological Survey has responsibility to compile and provide cartographic databases for landing sites, to assemble the engineering requirements associated with the landing site (e.g., _' altitude, rock frequency), and to evaluate potential sites in light of these constraints. Table II presents the current preliminary schedule outlining landing site selection mi for the 2001 mission. A similar procedure is expected to be followed for the subsequent landil selection processes. Results of First Landing Site Workshop Ames hosted a first Surveyor landing site workshop in January 199g. Abstracts meeting have been posted to the web and can be found http://cmex.arc.nasa.gov/Mars_2001/200 l_abs_vol.html. A primary goal of the workshop was to choose a latitude band in which the most sites lie in order to facilitate engineering design studies. Of the 65 landing sites presented meeting, 51 fell into the latitude band between 5N to 15S. At the time of the meeting, the on choosing a landing site for the 2001 mission under the assumption that the Athena rover on that mission. While this is no longer the case,.the range of proposed sites provides insight selection process. Most sites fell into one of 5 broad categories: (1) basins & lakes; (2) sites of potential hydrothermal mineralization; (3) highland/lowland boundary sites; (4) sites at channel mouths or deltaic deposits; and (5) younger impact crater on older material. In general each site presented one or more of the following characteristics: _" (1) evidence of water, (2) fossil concentration mechanism, (3) thermal energy source, (4) a preservation mechanism (e.g., rapid burial, mineralization), and (5) an excavation mechanism (e.g., crater, erosion). Suggested sites representing some of the broad catergories listed above include W. Arabia Mangala Valles, "White Rock" Crater, Kayne Crater, and Apollinaris Patera. The next workshop will be held in the summer of 1999 with additional annual follow. Individuals interested in subscribing to the site selection mailing list should contact Gulick (vgul [email protected], gov). " L Tab._le1: Engineering Constraints Input for '01 mission Current value Comment 15°S to 15°N will be narrowed' 120 x 20 km this has not been finalized 20 x 20 km <11 ° low high <1% Chance of rock >35 cm Table II: Preliminary Schedule: Mars Program Site Selection Process For 2001 Responsibility Schedule MSOP 10/13 - 11/7/97 ' SPO-I Ends MSOP 5/I/98 st SPO-2 Data Collection MSOP 5/26/98 - _ented 9/11/98 iaefocl MGSAssessment Phase CD available PDS 7/1/98 erwo Identify Engineering Constraints MED, Projects 10/98 _ight (Rocks, temperature range, elevation, etc.) Collect Surface Environmental Data MEDSO 10/97 - 11/98 (Roughness, rocks, topography, slopes, thermal inertia) SPO-I Release to Archive MSOP 10/15/98 Assembly of existing data PSG 12/1/98 MSP'98 Orbiter Launch NASA 12/10/98 Solicitation of Science Community for Project 12/98 Additional Landing Sites Steering Group Committee Meeting Steering Group 1/99 MSP'98 Lander Launch NASA I/3/99 MSP'98 Ops MSOP 1/00- 12/01 MSP'98 Release to Archive MSOP 12/00, 6/01, rabia Ted 12/01 SPO-2 Release to Archive MSOP 1/15/99 orkshops Steering Group Committee meeting Steering Group 3/99 actVirgit (LPSC) MGS Mapping begins MSOP 4/1/99 MGS Data Releases MSOP 10/1/99, 4/1/00 Collect MOC data from some selected 4/99 - 6/99 targets, analyze MOC data Science Evaluation Science Community Continues Landing Site Workshop Science Community 1/98, 7/99, 1/00, 1/01 Initial selection of a few sites Steering Group 7/99, 1/00 Focus study on selected sites Steering Group and 7/99- 12/99 ScienceCommunity FinalProjectSelection PSG, Project, MED 3/00 NASAselection/approval NASA 4/00 MSP'O1LanderLaunch NASA 4/7/01 MSP = Mars Surveyor Program; PDS = Planetary Data System; MEDSO = Mars Ex Division Science Office; MGS = Mars Global Surveyor; PSG = Project Science Group; MED= Exploration Division