rEESti42 INTEBESZLC IN ?HE EXEFCLAXION CE VENUS, NC. 8, 24 EAhCE 1EE6 Eagfllan update (Jet EroFulsicn Lab.) 14 F CSCL 0313 unc 1d s G3/91 440QO t Magellan (Formerly VRM) Update according to the previously agreed to Warren W. James schedule, but has taken action to start the procurement of the long-lead items needed Challenger Accident Impact on Magellan to replace this hardware so that Galileo will not be left without its spares. The launch accident which destroyed the Space Shuttle Challenger on January 28, A New Name for VRM 1986 is having major adverse impacts on all of the payloads that were scheduled to fly Following a two year on the Space Shuttle during this decade, decision-making process at NASA including Magellan (which was formerly Headquarters, a new name has been selected called Venus Radar Mapper). Launch delays for the Venus Radar Mapper (VRM) project. for the projects that were to precede us, The new name is Magellan and we will use i and a reduced number of Space Shuttles, MGN as its abbreviation. This name is .-.a*, WIII itsuii in increasea competition for consistent with NASA’s general plan of Shuttle launch services. naming major planetary missions after We do not presently know if we will famous historical persons; such ns be able to obtain a place on the Space scientists, astronomers, and explorers. i Shuttle manifest for our planned launch Magellan was deemed an appropriate name date in 1988. This is a question that for VRM because it connotes exploration, cannot be answered until the cause of the discovery and circumnavigation. Challenger accident has been determined Concurrent with the announcement and corrective solutions found to prevent of the new name, the project is selecting a this kind of accident from happening again. logo. Various designs for this have been Once that has been accomplished, NASA submitted and a panel is evaluating them. will revise its Shuttle payload manifest and The selection will be announced soon. we will know if it is possible to launch Magellan on our desired launch date. A Magellan Progress preliminary revision to the Space Shuttle manifest shows Magellan slipping to the The Magellan Project has been going 1989 launch opportunity, but the Magellan through a series of reviews as it progresses project continues to work to its present toward its 1988 launch date. The Final schedule. Mission Design Review was held on A second impact from the Challenger February 19, 1986 and no major problems accident involves the use of residual Galileo were uncovered, according to John hardware by the Magellan project. This Gerpheide, the Project Manager. The problem has arisen because the launch of Multi-mission Image Processing Laboratory Galileo has now slipped from May, 1986. to (MIPL) Baseline I1 Critical Design Review a later date. Magellan needs the use of (CDR) was also recently held and this this hardware now. The Magellan project system was judged to be in good shape for expects to receive the residual hardware handling our needs. Martin-Marietta has CW POOR QUALlrv V-gram successfully completed the CDRs on all of scientist's research activities so that, in its flight sub-systems, with the exception of sum, they answer the major questions about one. Everything is looking good for the the geology, geophysics, geochemistry and spacecraft. geological history of Venus, as described i However, the Radar Sensor and Alta below. reviews have revealed some design problems The Magellan RADIG was formed out which have been given special attention. of the Synthetic Aperture Radar (SAR) and i This has resulted in a tight schedule for Altimetry Investigation Groups of the building the Flight Model of the radar. An progenitor Venus Orbiting Imaging Radar important interface test for the radar and (VOIR) Mission, spacecraft is to start about May. scientists and The CDRs for the Missfon Omations System (MOS) and Radaf Data Pt&g 'i System are both planned for the second quarter of 1986 (although the MOS CDR has reconfirmed for Magellan. Of these, five I now slipped a month from its original are foreign residents and are supported by I schedule). The MOS flight operations phase their own governments. A list of the organization has been formed. A "tiger RADIG members and their affiliations is team" for evaluating the telemetry given in Table 1. Because of the large size processing subsystem requirements has of the RADIG membership, an executive defined both the high-rate and low-rate subset (identified in Table 1) has been requirements. chosen to represent it in the Project Significant progress has been made in Science Group (PSG), which meets defining and approving the data products quarterly during the years prior to the needed by the scientific investigators. launch of the spacecraft in April, 1988. To accomplish its assignment, the RADIG is organized around seven task THE MAGELLAN RADAR groups, each responsible for a general task INVESTIGATION GROUP as shown in Figure 1. The task groups Gordon Pettengill themselves cluster into two categories, depending on whether they are primarily Overview concerned with some aspect of Mission design, or with the scientific interpretation The Magellan (MGN) Radar of the data when received. We will be Investigation Group (RADIG) has the major hearing more about the plans of these task responsibility for the radar science of the groups, from their leaders, in future issues Magellan Mission. To do its job, the RADIG of the V-gram. must participate in the choice of parameters Most of the MGN data processing will for the radar system, in the design of be carried out at JPL, using the calibration and test procedures, in planning Multi-mission SAR Processing Laboratory the in-flight operations that relate to the (MSPL) and the Multi-mission Image radar system and, finally, in laying out the Processing Laboratory (MIPL). Some 1 processing and presentation of the data. specialized data processing will be done at The RADIG must make sure that all aspects other institutions, however, and we will of the Magellan mission are capable of hear more about these activities in future 1 producing results that satisfy the scientific V-Grams. I objectives of the Project. One of its most In order to compare the results from important tasks, of course, is to interpret the various experiments, it is necessary to the data resulting from the mission and to establish an accurate geodetic control publish the results of its studies. network for Venus, and to present the The RADIG is a collection of various types of radar observations in a individual scientists, each having his own cartographic style that is useful for perspective and field of expertise. The interpretation. The detailed specifications RADIG will attempt to coordinate each for the imaged and mapped products are ORIGINAL PAM 1s OF #K)R QUALm V-Gram Page 3 just now being finalized. The principal temperature and emissivity. data product that will receive wide In addition to being presented as distribution is a set of 62 maps in the standard cartographic maps and standard 1:5M U.S. Geological Survey photomosaics, the radar data from Magellan (USGS) planetary series. These maps will will also be made available in annotated display the SAR data at approximately 1-km digital form, thus preserving its full spatial resolution, and will contain altitude resolution and dynamic range. Careful contours. Beyond these, a set of about 200 documentation and archiving of the photomosaics will show the entire mapped accumulated results from MGN form an area of the planet at 225m resolution, while important part of data management for this about 250 photomosaics using the highest mission. Not only must the essential resolution SAR data (on the order of 100m) results be protected against deterioration will be produced for selected parts of the over time, but the relevant engineering planet. These maps and photomosaics will information needed to understand how these be used as the basemaps when presenting data were obtained must be stored so that data from the other experiments. future researchers can adequately interpret Complementary data products will include a these data. Also, the system used to store topographic map at about 10-km surface these data must provide easy access for resolution with a height accuracy of better users in the general planetary science than 50 m, and special products displaying community over a period of many years. surface roughness, reflectivity, brightness Table 1. RADIG Members Team Member Affiliation Raymond E. Arvidson (PSG) Washington University Victor R. Baker University of Arizona Joseph H. Binsack Massachusetts Institute of Technology Donald B. Campbell National Astronomy and Ionosphere Center (NAIC), Cornel1 University Merton E. Davies (PSG) The Rand Corporation Charles Elachi (PSG) Jet Propulsion Laboratory John E. Guest University of London James W. Head, I11 (PSG) Brown University William M. Kaula University of California, Los Angeles Kurt L. Lambeck Australian National University Franz W. Leberl Independent Consultant Harold C. MacDonald University of Arkansas Harold Masursky (PSG) U.S. Geological Survey, Flagstaff Daniel P. McKenzie Cambridge University Barry E. Parsons Oxford University Gordon H. Pettengill (PSG) Massachusetts Ins titu te of Technology Roger J. Phillips (PSG) Southern Methodist University R. Keith Raney (PSG) Canada Centre for Remote Sensing R. Stephen Saunders (PSG) Jet Propulsion Laboratory Gerald G. Schaber U.S. Geological Survey, Flagstaff Gerald S. Schubert University of California, Los Angeles Laurence A. Soderblom (PSG) U.S. Geological Survey, Flagstaff Sean C. Solomon (PSG) Massachusetts Institute of Technology H. Ray Stanley NASA, Wallops Island Manik Talwani Gulf Research and Development Co. G. Leonard Tyler (PSG) Stanford University John A. Wood Smithsonian Astrophysical Observatory It . Page 4 V-gram I U ORIGINAL PAQE IS V-Gram OF POOR,QUALcrV Page 5 RADIG Science Investigations the RADIG will develop hypotheses to explain the observed correlations, as well as The scientific tasks planned for the methods for testing them.