Mars Global Surveyor and 2001 Mars Odyssey Science Data Archives

Lunar and Planetary Science XXXIII (2002) 1303.pdf

MARS GLOBAL SURVEYOR AND 2001 MARS ODYSSEY SCIENCE DATA ARCHIVES. S. Slavney, R. E. Arvidson, and E. A. Guinness, Department of Earth and Planetary Sciences, McDonnell Center for the Space Sciences, Washington University, St. Louis, MO, 63130 ([email protected]).

Introduction: Science data sets from NASA's leases will occur every three months. GRS begins ac- Mars Exploration Program missions are archived with quiring data about 100 days after the start of mapping, the Planetary Data System (PDS) [1]. The PDS works with its first release in February 2003 [4]. with the missions to help them design and produce THEMIS generates multispectral visible and ther- quality, well-documented science archives. The PDS mal infrared images in image cube format. The total receives the archives produced by the missions and volume of raw and derived THEMIS data products is distributes them to the science community and the expected to be approximately five terabytes. general public. This abstract gives the status of science The GRS experiment generates gamma ray spectra data archives for the two Mars Exploration Program and derived maps of elemental ratios and concentra- missions currently in operation, Mars Global Surveyor tions, and the associated HEND and NS experiments and 2001 Mars Odyssey. produce spectra from which maps of hydrogen con- Mars Global Surveyor: The MGS spacecraft has centrations are derived. The data volume will not be been orbiting Mars since September 1997. Its primary as great as that of THEMIS, about 300 gigabytes. mission was completed January 31, 2001, and it is MARIE data sets are planned to consist of hydro- currently conducting an Extended Mission through gen and helium energy spectra associated with solar April 2002. A second Extended Mission has been ap- energetic events and galactic cosmic rays. In August proved to run through September 2004. Data from 2001 MARIE was turned off after it failed to respond MGS science experiments have been released regu- during a downlink, but mission personnel will attempt larly to the PDS [2, 3]. to recover the instrument after mapping begins. During the Primary Mission MGS generated over MGS and Odyssey Online Data Distribution: 500 gigabytes of science data products, archived on During the MGS Primary Mission the PDS distributed 815 CD-ROM, DVD-ROM, and CD-WO volumes. data both on CD-ROM and online. However, the ex- The data are available online from the PDS at this web pected increases in data volume from Odyssey and site: http://wufs.wustl.edu/missions/mgs/. Data from future missions will make CD-ROMs and even DVD- the MOC, MOLA, TES and MAG/ER experiments ROMs expensive to produce and impractical for users have been distributed on CD-ROMs and DVD-ROMs to access and store. Beginning with the MGS Ex- to about 300 planetary scientists. tended Mission, the PDS is moving away from data The MGS Extended Mission is expected to gener- distribution on CD-ROMs in favor of online access as ate about the same amount of science data as the Pri- the primary distribution method, with write-once CD mary Mission. As in the Primary Mission, instrument and DVD volumes available on request [5]. The PDS teams release data following a six-month validation will still maintain archival copies of data sets on period. The PDS is not distributing Extended Mission physical media for long term preservation. data products on CD-ROMs; they are available only The PDS is planning expanded online services to online. At present 25 volumes of Extended Mission help users locate and download data of interest. A sin- data are online. gle point of entry into the PDS will accept the user's 2001 Mars Odyssey: Odyssey entered Mars' orbit search criteria, locate the data among data stores at on October 24, 2001, and as of this writing is expected the various PDS Nodes, and return the data in user-se- to begin regular mapping on February 7, 2002, in a lected format. The first phase of the system will be Primary Mission extending through mid-2004. The operational by July 2002 and will provide access to Odyssey payload consists of THEMIS (Thermal Emis- Odyssey and MGS data. sion and Imaging System), MARIE (Martian Radia- The Odyssey GRS and THEMIS instrument teams tion Environment Experiment), and GRS (Gamma will be involved in the new system as PDS Data Nodes Ray Spectrometer), which includes the HEND (High for distributing their data. Each team facility will host Energy Neutron Detector) and NS (Neutron Spec- its data online, and will provide a product server to trometer) instruments. The first release of Odyssey respond to requests from the PDS distribution system. data to the PDS is scheduled for August 2002, and References: [1] Arvidson and Slavney (2000), will include THEMIS, HEND and NS data acquired Mars Exploration Program Data Management Plan, during the first month of mapping. Subsequent re- http://wufs.wustl.edu/missions/mep/dmp.html. [2] Ar- Lunar and Planetary Science XXXIII (2002) 1303.pdf

MGS AND ODYSSEY SCIENCE DATA ARCHIVES: S. Slavney et al.

vidson et al. (1998), Mars Global Surveyor Archive Generation, Validation, and Transfer Plan, MGS Document #542-312, http://wufs.wustl.edu/missions/- mgs/mgsarchive.pdf. [3] Arvidson et al. (1999), Ad- dendum: Updated Plan for Release of Mapping Phase Data. [4] Arvidson (2001), 2001 Mars Odyssey Or- biter Archive Generation, Validation, and Transfer Plan, JPL D-20679, http://wufs.wustl.edu/missions- /odyssey/docs/ody_archive.pdf. [5] Nelson et al. (2001), Mars Exploration Program: Expected Data Volumes and Data Access Requirements for Research and Public Engagement, http://wufs.wustl.edu/missions/mep/datarecomm.pdf.