Hi Listers, Since I started lurking this list last year, I have been quite impressed at the remarkable understanding and knowledge of orbital mechanics that many of you have. You're way past my own level. I truly wish I had the time to devote to get to the point where many of you are. I have a question that many of you should be able to answer, and it would be interesting to see which of you can come the closest with your prediction. I have just learned that approximately 6 hours and 14 minutes after the Shuttle is scheduled to undock from the ISS, it will make a very nearly overhead pass here, and I'm wondering what the apparent distance will be between them at this time. Heavens Above lists a difference of 14 seconds between the zenith of the two passes tomorrow night, which would, I suppose, suggest a separation of about 20 degrees (a very rough guess) assuming that both objects are traveling in the same line, but I wonder if H-A is taking into account whatever engine burns are scheduled to take place between now and then. Interestingly, H-A also shows both objects reaching a zenith of 87 degress, but it shows the azimuth of the zenith of the ISS pass as being WSW, whereas the azimuth of the Shuttle pass is listed as just West. H-A has been fairly accurate for me, but in this case I decided to check NASA's Skywatch. Besides eventually crashing my MSIE, Skywatch predicts no degree of separation during this pass tomorrow night. Worse yet, it reports a pass that's a whopping 44 minutes earlier! I recall H-A as being less than accurate on occasion with respect to the Shuttle specifically, which I assumed to be due to the fact that some maneuvering was not accounted for, and one would expect NASA to have the most accurate data with respect to one of their own crafts. Apologies for this long message, and for not having the time to learn this discipline the way that it should be learned, but I still truly enjoy stepping outside in our clear West Virginia skies to see things, and the ISS and Shuttle flying in tandem is surely one of my all time favorite sights. I'd like to tell me friends and neighbors to take a look, but now I'm not sure when to tell them to look. Our own location (in decimal) is 38.067 North, 80.434 West, and I'll bet that some of you all could tell me where and when to look with even more accuracy that H-A and Skywatch combined! In particular, I'd be very interested in knowing what some of you would expect to see in terms of the amount of separation between the two objects. Many Thanks and Best Regards, Art Almost Heaven Overseas HC 67 Box 539 BB Renick WV 24966 Phone 304-497-2610 Fax 304-497-2698 e-mail art@almostheaven.net http://www.almostheaven.net/ ---------------------------------------------- Offering direct sales of Saunas, Steamrooms and the widest selection of Pool, Spa, Sauna and Hot Tub Equipment worldwide. "We're not just overseas anymore" ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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