A Case Study of Post-CME Flow
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Post-CME Flow↗
Engineering topics
Goldstein, Raymond
Publications and source records attributed to Goldstein, Raymond.
Cometary Coma Chemical Composition (C4) Mission
Cometary exploration remains of great importance to virtually all of space science. Because comets are presumed to be remnants of the early solar nebula, they are expected to provide fundamental knowledge as to the origin and development of the solar system as well as to be key to understanding of the source of volatiles and even life itself in the inner solar system. Clearly the time for a detailed study of the composition of these apparent messages from the past has come. A comet rendezvous mission, the Cometary Coma Chemical Composition (C4) Mission, is now being studied as a candidate for the new Discovery program. This mission is a highly-focussed and usefully-limited subset of the Cometary Rendezvous Asteroid Flyby (CRAF) Mission. The C4 mission will concentrate on measurements that will produce an understanding of the composition and physical makeup of a cometary nucleus. The core science goals of the C4 mission are 1) to determine the chemical, elemental, and isotopic composition of a cometary nucleus and 2) to characterize the chemical and isotopic nature of its atmosphere. A related goal is to obtain temporal information about the development of the cometary coma as a function of time and orbital position. The four short-period comets -- Tempel 1, Tempel 2, Churyumov-Gerasimenko, and Wirtanen -which all appear to have acceptable dust production rates, were identified as candidate targets. Mission opportunities have been identified beginning as early as 1998. Tempel I with a launch in 1999, however, remains the baseline comet for studies of and planning the C4 mission. The C4 mission incorporates two science instruments and two engineering instruments in the payload to obtain the desired measurements. The science instruments include an advanced version of the Cometary Ice and Dust Experiment (CIDEX), a mini-CIDEX with a sample collection system, an X-ray Fluorescence Spectrometer and a Pyrolysis-Gas Chromatograph, and a simplified version of the Neutral Gas and Ion Mass Spectrometer (NIGMS). Both of these instruments have substantial heritage as they are based on those developed for the CRAF Mission. The engineering instruments include a simplified Comet Dust Environmental Monitor (SCODEM) and a navigational Camera, NAVCAM. While neither of the instruments will be permitted to establish science requirements, it is anticipated that significant science return will be accomplished Radio science will also be included.
Carle, Glenn C.↗
Comment on 'Ion acceleration at the contact surface of Comet P/Halley', by C. Gurgiolo and J. D. Winningham
It is argued that some of the conclusions in Gurgiolo and Winningham (GW, 1990) are unlikely. Arguments are made against the claim by GW that two 'ion enhancements' seen near the comet ionopause are due to impulse acceleration of the boundary producing heated plasma pulses, and also against the conclusions of GW that ions within the inner coma are ion beams narrow in energy and traveling across the cavity roughly parallel and antiparallel to the spacecraft motion and reflecting from the cavity boundary. In a reply, GW reaffirm their earlier findings.
Goldstein, Raymond↗
Energetic ion fluxes in the inner coma of Comet P/Halley
The particle phenomenon observed inside the magnetic field-free cavity near the nucleus of Comet P/Halley by the Giotto Ion Mass Spectrometer High-Energy Range Spectrometer sensor is studied. The question of access to the cavity of particles ionized farther out in the coma is addressed. A quantitative model of a mechanism for creating the observed fast-ion fluxes in the cavity is presented.
Eviatar, Aharon↗