We employed numerical modeling of the martian atmosphere, and our expertise in understanding martian atmospheric processes, to better understand the coupling between lower and upper atmosphere processes. One practical application of this work has been our involvement with the ongoing atmospheric aerobraking which the Mars Global Surveyor (MGS) spacecraft is currently undergoing at Mars. Aerobraking is a process whereby a spacecraft, in an elliptical orbit, passes through the upper layers of the atmosphere (in this instance Mars). This passage through the atmosphere 'drags'upon the spacecraft, gradually reducing its orbital velocity. This has the effect, over time, of converting the elliptical orbit to a circular orbit, which is the desired mapping orbit for MGS. Carrying out aerobraking eliminates the need for carrying large amounts of fuel on the spacecraft to execute an engine burn to achieve the desired orbit. Damage to one of MGS's solar panels shortly after launch has resulted in a less aggressive extended in time aerobraking phase which will not end until March, 1999. Phase I extended from Sept. 1997 through March 1998. The leader of each of the daily AAG meetings took the results of that meeting (current state of the atmosphere, identification of any time trends or spatial patterns in upper atmosphere densities, etc.) forward to the Aerobraking Planning Group (APG) meeting, at which time the decision was made to not change MGS orbit, to lower the orbit to reach higher densities (greater 'drag'), or raise the orbit to avoid experiencing excessive, possibly damaging densities.


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    Title :

    Martian Meteorology: Determination of Large Scale Weather Patterns from Surface Measurements


    Contributors:

    Publication date :

    1998


    Size :

    5 pages


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English




    Martian Meteorology: Determination of Large Scale Weather Patterns from Surface Measurements

    Murphy, James R. / Bridger, Alison F. C. / Haberle, Robert M. | NTRS | 1998



    Martian Meteorology: Determination of Large Scale Weather Patterns from Surface Measurements

    Murphy, James R. / Haberle, Robert M. / Bridger, Alison F. C. | NTRS | 1998