title: A proposed Comet Nucleus Penetrator for the Comet Rendezvous Asteroid Flyby mission.
abstract: Among the major objectives of NASA's program of space exploration is a better understanding of the origin and evolution of the solar system.  Crucial to this objective is the study of comets, which are thought to be the most primitive, pristine bodies remaining in the solar system.  The importance of the study of comets has led NASA to plan a mission to rendezvous with comet Tempel 2 in 1997.  Critical to the understanding of comets will be measurements of the nucleus material to determine its elemental and isotopic composition, its mechanical properties, and its thermal state and properties.  This paper describes a proposal for a Comet Nucleus Penetrator to accomplish these measurement goals.  The Comet Nucleus Penetrator will implant instruments into the comet's nucleus beneath a probable volatile-depleted surface mantle into material more representative of the bulk composition of the nucleus.
authors.affiliation: NASA Ames Research Center, Moffett Field, Calif, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Swenson
authors.forename: S W
authors.initials: SW
authors.lastname: Squyres
authors.forename: T C
authors.initials: TC
authors.lastname: Knight
mesh_terms: D000512:Alpha Particles; D004602:Elements; D007053:Ice / Q000032:analysis; D019110:Meteoroids; D012107:Research Design; D016082:Solar System; D013026:Space Flight / Q000295:instrumentation*; D018531:Spacecraft / Q000295:instrumentation*; D013051:Spectrometry, Gamma / Q000295:instrumentation
chemical_list: D004602:Elements; D007053:Ice