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Comet and Asteroid Ephemerides for Spacecraft Encounters

Published online by Cambridge University Press:  12 April 2016

Donald K. Yeomans
Donald K. Yeomans*
Affiliation:
Jet Propulsion Laboratory, California Institute of Technology Pasadena, California, USA

Abstract

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To a significant degree, the success of spacecraft missions to comets and asteroids depends upon the accuracy of the target body ephemerides. In turn, accurate ephemerides depend upon the quality of the astrometric data set used in determining the object’s orbit and the accuracy with which the target body’s motion can be modelled. Using error analyses studies of the target bodies for the NEAR, Muses-C, Clementine 2, Stardust, and Rosetta missions, conclusions are drawn as to how to minimize target body position uncertainties at the times of encounter. In general, these uncertainties will be minimized when the object has a good number of optical observations spread over several orbital periods. If a target body lacks a lengthy data interval, its ephemeris uncertainties can be dramatically reduced with the use of radar Doppler and delay data taken when the body is relatively close to the Earth. The combination of radar and optical angle data taken at close Earth distances just before a spacecraft encounter can result in surprisingly small target body ephemeris uncertainties.

Type
Dynamics and Astrometry: Present and Future
Information
International Astronomical Union Colloquium , Volume 165: Dynamics and Astrometry of Natural and Artificial Celestial Bodies , 1997 , pp. 1 - 12
Copyright
Copyright © Kluwer 1997

References

Marsden, B.G., Sekanina, Z., and Yeomans, D.K.: 1973, “Comets and nongravitational forces. V”, Astron. J. 78, 211–225.Google Scholar
Monet, A.K.B., Stone, R.C., Monet, D.G., Dahn, C.C., Harris, H.C., Legget, S.K., Pier, J.R., Vrba, F.J., and Walker, R.L.: 1994, “Astrometry for the Galileo mission. I. Asteroid encounters”, Astron. J. 107, 2290–2294.Google Scholar
Owen, W.M. and Yeomans, D.K.: 1994, “The overlapping plates method applied to CCD observations of 243 Ida”, Astron. J. 107, 2295–2298.Google Scholar
Ostro, S.J., Campbell, D.B., Chandler, J.F., Shapiro, I.I., Hine, A.A., Velez, R., Jurgens, R.F., Rosema, K.D., Winkler, R. and Yeomans, D.K.: 1991, “Asteroid radar astrometry”, Astron. J. 102, 1490–1502.Google Scholar
Roeser, S.: 1987, “Catalogue of astrometrie observations of comet P/Halley at its apparition 1909-1911”, Astron. Astrophys., Suppl. Ser. 71, 363–395.Google Scholar
Stone, R.C., Monet, D.G., Monet, A.K.B., Walker, R.L., Abies, H.D., Bird, A.R., and Harris, F.H.: 1996, “The Flagstaff Astrometrie Scanning Transit Telescope (FASTT) and star positions determined in the extragalactic reference frame”, Astron. J. 111, 1721–1742.CrossRefGoogle Scholar
Yeomans, D.K.: 1994a, “Astrometry and space missions to asteroids and comets”, in: Galactic and Solar System Optical Astrometry (Morrison, L.V, Gilmore, G.F., eds), Cambridge University Press, 276–285.Google Scholar
Yeomans, D.K.: 1994b, “A review of comets and nongravitational forces”, in: Asteroids, Comets, Meteors 1993(Milani, A., Di Martino, M., Cellino, A., eds), Kluwer, Dordrecht, 241–254.CrossRefGoogle Scholar
Yeomans, D.K., Ostro, S.J., and Chodas, P.W.: 1987, “Radar astrometry of near-Earth asteroids”, Astron. J. 94, 189–200.Google Scholar
Yeomans, D.K. and Chodas, P.W.: 1989, “An asymmetric outgassing model for cometary nongravitational accelerations”, Astron. J. 98, 1083–1093.CrossRefGoogle Scholar
Yeomans, D.K., Chodas, P.W., Keesey, M.S., and Ostro, S.J.: 1992, “Asteroid and comet orbits using radar data”, Astron. J. 103, 303–317.Google Scholar
Yeomans, D.K., Chodas, P.W., Keesey, M.S., Owen, W.M., and Wimberly, R.N.: 1993, “Targeting an asteroid: The Galileo spacecraft’s encounter with 951 Gaspra”, Astron. J. 105, 1547–1552.CrossRefGoogle Scholar