Pamela E. Clark

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1Goddard Space Flight Center, Code 691, Greenbelt, Maryland 20771, USA 2The Catholic University of America, Physics Department, 620 Michigan Avenue Northeast, Washington, D.C. 20064, USA 3Cornell University, Space Sciences Building, Ithaca, New York 14853, USA 4Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution,(More)
The regulation of proteoglycan synthesis in a fibrocartilaginous tissue by mechanical loading was assessed in vitro. Discs of bovine tendon fibrocartilage were loaded daily with unconfined, cyclic, uniaxial compression (5 s/min, 20 min/day) and the synthesis of large and small proteoglycans was measured by incorporation of [35S]sulfate. All discs(More)
Hemerythrin from coelomic cells of Phascolosoma lurco (syn. P. arcuatum) was isolated by gel filtration as two components, hemerythrin-I (25%) and hemerythrin-II (75%). The Mössbauer spectrum of oxyhemerythrin-II consisted of two pairs of lines of the same isomer shift (0.5 mm s(-1) corresponding to Fe(III) but different quadrupole splitting (1.01 and 2.02(More)
We describe the Prospecting ANTS Mission (PAM) whose object is to explore the resource potential the Solar System's Asteroid Belt. The mission is consistent with the present NASA strategic plan for the HEDS (Human Exploration and Development of Space) enterprise. In this plan, the automated discovery of space resources is envisioned as a building block for(More)
A reconfigurable space filling robotic architecture has a wide range of possible applications. One of the more intriguing possibilities is mobility in very irregular and otherwise impassable terrain. NASA Goddard Space Flight Center is developing the third generation of its addressable reconfigurable technology (ART) tetrahedral robotics architecture. An(More)
With the insertion of the NEAR spacecraft into orbit around the asteroid 433 Eros, a new stage of asteroid exploration has begun, with the return of spatially resolved mineralogical, geological, and chemical information from specific asteroids. In this paper, we outline the features of a partially differentiated asteroid using the acapulcoite and lodranite(More)
The Significance of Dust: Dust studies have already been identified as crucial components of missions to the Moon, Mars, asteroids, and Mercury over the next decade [1,2]. Detailed study of the physical and chemical nature of the fine particulate portion of regoliths of planetary bodies is a key to understanding micrometeorite bombardment and the nature of(More)
High Mobility Requirement for Exploration of Rugged Terrain: Reconfigurable architecture [1,2] is essential in exploration because reaching features of the great potential interest, whether searching for life in volcanic terrain or water in at the bottom of craters, will require crossing a wide range of terrains [3]. Such areas of interest are largely(More)
Some of the most scientifically interesting terrain is among the most inaccessible, presenting problems for all mobility strategies. Lava flows, for example, can have structure at all scale sizes rendering traversal via appendage or wheel difficult at best. NASA researchers have been developing an innovative mechanical structure that provides mobility in(More)