RE: ISS orbit on March 6, 2011

From: Frank@reednavigation.com
Date: Thu May 05 2011 - 02:05:31 UTC

  • Next message: Russell Eberst: "2011MAY4.OBS"

    Ted Molczan, you wrote:
    "Space Track provides historical TLEs."
    
    Thank you. I guess I never noticed that on the space-track site. It's been a few years since I was really interested in satellite observing, and I had no idea where to find my space-track user details. Lo and behold, I had put them into the URL in my favorites for quicker login.
    
    Anyway, that worked great. I have the data I needed. Thank you again! 
    
    If anyone is interested, there is a lovely photo of a sliver of a crescent moon taken from the ISS in March with the Moon and various stars in Pisces visible above the backlit limb of the Earth after the Sun has set. It shows very nicely how the twilight glow is the principal source of illumination for a satellite in the Earth's shadow. That's what originally got me interested in the photo, but it's also an interesting navigation puzzler. From the position of the Moon among the stars, the time (UT) can be determined if the observer's position is known, or the position of the ISS can be determined if the UT is known. Since we also have altitudes of stars relative to "some" horizon, it's possible to solve for both. The photo could only be taken from one place in space at one moment of time. That's off-topic for SeeSat-L, so if any of you are interested, you are welcome to join the discussion on NavList at www.fer3.com/arc. It's in the topic "An exotic lunar distance puzzle" an!
     d the first message on it (from me) is located here: 
    http://www.fer3.com/arc/m2.aspx?i=116272
    
    -FER
    
    
    
    
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