RE: upcoming solar sail launch

From: Ted Molczan (molczan@rogers.com)
Date: Sun Feb 06 2005 - 11:22:42 EST

  • Next message: Kevin Fetter: "two satellites near each other"

    Kevin Fetter wrote:
    
    > On Mar 1 a Volna rocket will launch a satellite called cosmos 
    > 1 into a approx 825 km high 78 degree inclination orbit.
    > 
    > http://www.planetary.org/solarsail/
    > 
    > This should make for a nice satellite.
    
    Indeed, and the web site provides sufficient information to estimate the
    approximate orbital elements.
    
    Based upon the countdown clock on the above web page, I estimate launch on 2005
    Mar 01 at 04:56:10 UTC.
    
    The following page provides fairly detailed information on the planned orbit,
    and the time of orbit insertion, 1168 s (19m28s) after launch:
    
    http://www.planetary.org/solarsail/images/Sail_Pics/2nd%20phase%20demo.jpg
    
    The timeline provides an approximate time and location along the orbital ground
    track: 
    
    http://www.planetary.org/solarsail/timeline.html
    
    "[one of two] portable [tracking] stations will be located on the island of
    Majuro, in the Marshall Islands of the central Pacific. Majuro is the first land
    point in the spacecraft's orbital path, and it will be passing over the island 4
    minutes after orbit insertion. The Majuro station should be able to track the
    spacecraft for around 10 minutes."
    
    So the pass over Majuro should occur about 23m28s after launch. Based upon the
    location of the launch site, and description of the ground track, the pass over
    Majuro will be southbound. The following elements place the satellite directly
    over Majuro (7.1 N, 171.383 E) at about 05:19:38 UTC:
                                                             832 X 840 km
    1 70900U 70900A   05060.22196759  .00000000  00000-0  00000-0 0    07
    2 70900  78.6000 231.8000 0005500   0.0000 172.6800 14.16100000    00
    
    This orbit is consistent with the planned subsequent acquisition by one of the
    permanent tracking stations, Panska Ves in the Czech Republic (50.533 N, 14.550
    E), about 1h14m after orbital insertion.
    
    This orbit results in pre-dawn passes over much of the inhabited Earth. Russell
    Eberst will have a high elevation pass near the end of civil twilight.
    
    The real orbit is bound to be somewhat different, but this should be suitable
    for rough observation planning purposes.
    
    It occurs to me that hobbyist visual tracking might of some use in the first
    hours after launch. Perhaps someone should contact the project managers and ask
    whether we might of assistance. All we would require are accurate pre-flight
    elements, and information on the dimensions of the spacecraft in the various
    expected stages of deployment (my guess is that it is small without the sail).
    Then, we could determine whether or not any of our sensors would be able and
    willing to get up early and have a look.
    
    Ted Molczan
    
    
    
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