RE: NanoSail-D not seen

From: Ted Molczan (
Date: Sun Jan 23 2011 - 16:02:57 UTC

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    Viktor Voropaev wrote:
    > According to reports from Yarovoye (Russia) the satellite had
    > a brightness of about 2m. More information and photos is here:
    > (in Russian only, I'll translate if necessary).
    I have not seen any confirmation that the images are of NanoSail-D, so I analyzed one of them, and
    it appears to correlate closely with the current TLE provided by NASA:
    1 90027U 0        11021.03111096 +.00000496 +00000-0 +78023-4 0 00033
    2 90027 071.9761 003.6513 0021431 200.5132 159.5103 14.77037263000254
    The observer's stated coordinates are 52.9206N, 78.5828E. Altitude not stated, but Heavens-Above
    reports ~100 m for several locations in the vicinity. It is not clear whether this is the exact site
    from which the image was taken, but that is what I assume.
    The filename of the second of the three images (URL below) indicates that it was taken on 2011 Jan
    22 at 18:45:00, which is the observer's local time, 6 h ahead of UTC; therefore, ~12:45 UTC.;topic=7897.0;attach=286144
    The trail begins near 22:59, +22:56, and ends near 22:57, +27:11 (2000.0). If the site coordinates
    and TLE are accurate, then the positions correspond to approximately 12:45:08 and 12:45:18 UTC,
    respectively, and they agree with the predicted track to within a few one-hundredths of a degree of
    arc. The duration is in agreement with the stated 10 s exposure.
    A check against all objects in known orbits reveals no other likely candidates within 2 min time and
    2 deg cross-track.
    According to NASA, perturbations due to drag and SRP (solar radiation pressure) are expected to take
    the object out of orbit within 70 to 120 days of sail deployment.
    USSTRATCOM apparently has yet to catalogue this object, so for now, I suggest that we adopt the next
    available COSPAR designation, 2010-062L. For the catalogue number, I suggest that we use the next
    available one in the hobbyist UNID numbering sequence, which is 90086.
    Ted Molczan
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