SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 7 - April 07, 2006

91 LUNAR AND PLANETARY SCIENCE AND EXPLORATION
Includes planetology; selenology; meteorites; comets; and manned and unmanned planetary and lunar flights.

For spacecraft design or space stations see 18 Spacecraft Design, Testing and Performance.

20060009305 NASA Langley Research Center, Hampton, VA, USA

Mars Science Laboratory Launch-Arrival Space Study: A Pork Chop Plot Analysis

Cianciolo, Alicia Dwyer; Powell, Richard; Lockwood, Mary Kae; [2006]; 11 pp.; In English; 2006 IEEE Aerospace Conference, 4-11 Mar. 2006, Big Sky, TM, USA; Original contains color and black and white illustrations Contract(s)/Grant(s): WBS 464.02.07.07; No Copyright; Avail.: CASI: A03, Hardcopy

Launch-Arrival, or 'pork chop', plot analysis can provide mission designers with valuable information and insight into a specific launch and arrival space selected for a mission. The study begins with the array of entry states for each pair of selected Earth launch and Mars arrival dates, and nominal entry, descent and landing trajectories are simulated for each pair. Parameters of interest, such as maximum heat rate, are plotted in launch-arrival space. The plots help to quickly identify launch and arrival regions that are not feasible under current constraints or technology and also provide information as to what technologies may need to be developed to reach a desired region. This paper provides a discussion of the development, application, and results of a pork chop plot analysis to the Mars Science Laboratory mission. This technique is easily applicable to other missions at Mars and other destinations. Author

Mars Missions; Descent Trajectories; Atmospheric Entry; Launching

20060010018 Lunar and Planetary Inst., Houston, TX, USA

Distribution and stratigraphy of basaltic units in Maria Tranquillitatis and Fecunditatis: A Clementine perspective

Rajmon, D.; Spudis, P.; Meteoritics and Planetary Science; 2004; Volume 39, No. 10, pp. 1699-1720; In English; Original contains color and black and white illustrations Contract(s)/Grant(s): NCC5-679 Report No.(s): LPI-Contrib-1210; Copyright; Avail.: Other Sources

Maria Tranquillitatis and Fecunditatis have been mapped based on Clementine image mosaics and derived iron and titanium maps. Impact craters served as stratigraphic probes enabling better delineation of compositionally different basaltic units, determining the distribution of subsurface basalts, and providing estimates of total basalt thickness and the thickness of the surface units. Collected data indicate that volcanism in these maria started with the eruption of low-Ti basalts and evolved toward medium- and high-Ti basalts. Some of the high-Ti basalts in Mare Tranquillitatis began erupting early and were contemporaneous with the low- and medium-Ti basalts; these units form the oldest units exposed on the mare surface. Mare Tranquillitatis is mostly covered with high- Ti basalts. In Mare Fecunditatis, the volume of erupting basalts clearly decreased as the Ti content increased, and the high-Ti basalts occur as a few patches on the mare surface. The basalt in both maria is on the order of several hundred meters thick and locally may be as thick as 1600 m. The new basalt thickness estimates generally fall within the range set by earlier studies, although locally differ. The medium- to high-Ti basalts exposed at the surfaces of both maria are meters to tens of meters thick. Author

Clementine Spacecraft; Lunar Maria; Stratigraphy; Basalt; Craters; Volcanology

20060010021 NASA Johnson Space Center, Houston, TX, USA

Trade Space Assessment for Human Exploration Mission Design

Joosten, B. Kent; January 2006; 1 pp.; In English; 1st Space Exploration Conference: Continuing the Voyage of Discovery, 30 Jan. - 1 Feb 2005, Orlando, FL, USA Contract(s)/Grant(s): 7611002E0566; No Copyright; Avail.: Other Sources; Abstract Only

Many human space exploration mission architecture assessments have been performed over the years by diverse organizations and individuals. Direct comparison of metrics among these studies is extremely difficult due to widely varying assumptions involving projected technology readiness, mission goals, acceptable risk criteria, and socio-political environments. However, constant over the years have been the physical laws of celestial dynamics and rocket propulsion systems. A finite diverse yet finite architecture trade space should exist which captures methods of human exploration - particularly of the Moon and Mars - by delineating technical trades and cataloging the physically realizable options of each. A particular architectural approach should then have a traceable path through this 'trade tree'. It should be pointed out that not every permutation of paths will result in a physically realizable mission approach, but cataloging options that have been examined by past studies should help guide future analysis. This effort was undertaken in two phases by multi-center NASA working groups in the spring and summer of 2004 using more than thirty years of past studies to 'flesh out' the Moon-Mars human exploration trade space. The results are presented, not as a 'trade tree', which would be unwieldy, but as a 'menu' of potential technical options as a function of mission phases. This is envisioned as a tool to aid future mission designers by offering guidance to relevant past analyses. Author

Mission Planning; Mars Exploration; Technology Assessment; Space Exploration

Source: NASA