Abstract Doppler and ranging measurements using the radio signal of the GIOTTO spacecraft were taken before, during, and after the encounter with Comet Halley on 13 14 March 1986. The spacecraft velocity was found to decrease by a total of 23.3 cm s−1 due to impacting gas and (primarily) dust in the cometary atmosphere. A preliminary dust production rate Q d ⋍ 10 × 103 kg s −1 is found to be consistent with this deceleration. Power spectra of the carrier phase fluctuations reveal an increase in level and a flattening of the spectrum just prior to encounter, presumably associated with the enhanced dust impact rate. Finally, simulated Doppler time profiles are computed using the radial dependence of plasma density observed by the GIOTTO in situ investigations. It is shown that the cometary electron content profile would have been clearly seen if a dual-frequency downlink radio configuration had been available at encounter.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Preliminary results of the Giotto radio science experiment


    Contributors:
    Edenhofer, P. (author) / Bird, M.K. (author) / Volland, H. (author) / Esposito, P.B. (author) / Porsche, H. (author)

    Published in:

    Advances in Space Research ; 5 , 12 ; 201-209


    Publication date :

    1985-01-01


    Size :

    9 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Preliminary results of the Giotto radio science experiment

    Edenhofer, P. / Bird, M. K. / Volland, H. et al. | NTRS | 1985


    Measurement technique for the Giotto radio science experiment

    Edenhofer, P. / Bird, M.K. / Buschert, H. et al. | Tema Archive | 1987


    The Giotto magnetometer experiment

    Neubauer, F.M. / Acuna, M.H. / Burlaga, L.F. et al. | Tema Archive | 1987


    The Giotto electron plasma experiment

    Reme, H. / Cotin, F. / Cros, A. et al. | Tema Archive | 1987