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Triple Spacecraft Sighting
Greetings,
Last night at 22:10-ish Mountain Daylight Time in Boise, Idaho, I observed the ISS/Shuttle pair as they passed by, not quite overhead. I have watched numerous ISS and Shuttle passes and have been excited to watch this particular one with our own Barbara Morgan (astronaut/teacher) aboard. I have even watched a few passes through a small telescope - very interesting to see structure! But last night's sighting was more unusual. I was waiting to see the ISS rise, which I expected to preceed the shutle since the Endeavor had undocked earlier in the day. I suddenly found "it" a little higher in the sky than I expected but along the expected flight path. Perhaps I noticed it so late because it was dimmer, perhaps mag 3 when it was predicted to be mag -1. I watched it move slowly across the sky and even managed to get a 4.5" Dob on it a few times. Interestingly I could not see the solar panels or any detail as I had just the two previous nights. Nor could I see the shutle anywhere... even though it was moving to the southeast. I expressed my disappointment to my wife who was watching with me when she looked to the west and said, "Then what are those?" Sure enough, a brighter ISS followed by a slightly dimmer shuttle were tracking along the expected flight path. The shuttle was perhaps 5 degrees (about 7 seconds time-wise) behind the ISS. I did get the Dob onto the ISS to see the solar panels and then left it pointing at one location to let the shuttle catch up and pass through the field of view. Sure enough, the shuttle had a slight teardrop shape. So now the big mystery: what was the mag 3 object that preceeded the ISS/shuttle pair by about a minute, maybe minute and a half??? I checked Heavens-Above and it listed nothing but the ISS/shuttle at that time in that location. Without any way to prove it, I would say the first object was in the "same"orbit as the ISS - could it be a Progress re-supply ship? I really wouldn't expect to see one near the ISS when the shuttle is manoevering so close. Regardless of what it was, it was very exciting to see THREE spacecraft at once. I just hope the first one was a "friendly" one... ;-} Jim Hewitt Boise, ID |
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Triple Spacecraft Sighting
In sci.astro.amateur message , Mon, 20
Aug 2007 11:08:51, Jim Hewitt posted: So now the big mystery: what was the mag 3 object that preceeded the ISS/shuttle pair by about a minute, maybe minute and a half??? One of the two items (Early Ammonia Servicer, camera mounting) launched manually by Clayton Anderson 2007-07-23? ? -- (c) John Stockton, Surrey, UK. Turnpike v6.05 MIME. Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links; Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc. No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News. |
#3
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Triple Spacecraft Sighting
"Jim Hewitt" wrote in message ... snippage So now the big mystery: what was the mag 3 object that preceeded the ISS/shuttle pair by about a minute, maybe minute and a half??? I checked Heavens-Above and it listed nothing but the ISS/shuttle at that time in that location. Without any way to prove it, I would say the first object was in the "same"orbit as the ISS - could it be a Progress re-supply ship? I really wouldn't expect to see one near the ISS when the shuttle is manoevering so close. Perhaps it was a cargo ship detaching itself from the ISS? |
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Triple Spacecraft Sighting
On Aug 20, 1:08 pm, "Jim Hewitt" wrote:
So now the big mystery: what was the mag 3 object that preceeded the ISS/shuttle pair by about a minute, maybe minute and a half??? I checked Heavens-Above and it listed nothing but the ISS/shuttle at that time in that location. Without any way to prove it, I would say the first object was in the "same"orbit as the ISS - could it be a Progress re-supply ship? I really wouldn't expect to see one near the ISS when the shuttle is manoevering so close. I believe that you may have seen USA 193 (06057A / 29651). It preceded ISS by 2.5 min, following nearly the same path, but culminating 14 deg higher (48 deg vs 34 deg). Its predicted maximum magnitude was 2.1, but the uncertainty was at least a couple magnitudes. Heavens-Above has current elements, but not its standard magnitude (4.3 at 1000 km, 90 deg phase angle), so it does not show up in predictions. Regardless of what it was, it was very exciting to see THREE spacecraft at once. I just hope the first one was a "friendly" one... ;-} It is believed to be an experimental NRO imaging reconnaissance satellite. It reportedly died within days of launch. Ted Molczan |
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Triple Spacecraft Sighting
wrote in message
ups.com... On Aug 20, 1:08 pm, "Jim Hewitt" wrote: So now the big mystery: what was the mag 3 object that preceeded the ISS/shuttle pair by about a minute, maybe minute and a half??? I checked Heavens-Above and it listed nothing but the ISS/shuttle at that time in that location. Without any way to prove it, I would say the first object was in the "same"orbit as the ISS - could it be a Progress re-supply ship? I really wouldn't expect to see one near the ISS when the shuttle is manoevering so close. I believe that you may have seen USA 193 (06057A / 29651). It preceded ISS by 2.5 min, following nearly the same path, but culminating 14 deg higher (48 deg vs 34 deg). Its predicted maximum magnitude was 2.1, but the uncertainty was at least a couple magnitudes. Well, I'd guess that was it. As I now recall, the first object was indeed a bit higher than the ISS. And it may have been much more than a minute ahead - I watched it travel from due west to past south, moving east - that should be a couple of minutes. When the ISS was about 15 degrees up, nearly due west, the first one was perhaps south-south-east and could have been 45 degrees up. But it was close enough to the predicted ISS path that it threw me for a litle loop ("Why is it so DIM?!!"). What source do you use to find out about these thing? I've relied on Heavens-Above though I have clearly seen other things in the past that HA did not predict for me or tell me about after. Thanks for your help. Jim |
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Triple Spacecraft Sighting
On Aug 20, 6:36 pm, "Jim Hewitt" wrote:
wrote in message I believe that you may have seen USA 193 (06057A / 29651). It preceded ISS by 2.5 min, following nearly the same path, but culminating 14 deg higher (48 deg vs 34 deg). Its predicted maximum magnitude was 2.1, but the uncertainty was at least a couple magnitudes. Well, I'd guess that was it. As I now recall, the first object was indeed a bit higher than the ISS. And it may have been much more than a minute ahead - I watched it travel from due west to past south, moving east - that should be a couple of minutes. When the ISS was about 15 degrees up, nearly due west, the first one was perhaps south-south-east and could have been 45 degrees up. That fits very well. At 22:10:20 PDT, ISS reached elevation 15 deg, at azimuth 282 deg. At that moment, USA 193 was at elevation 41 deg, azimuth 192 deg. But it was close enough to the predicted ISS path that it threw me for a litle loop ("Why is it so DIM?!!"). This sort of situation arises quite often, due to the large number of objects in orbit. What source do you use to find out about these thing? I've relied on Heavens-Above though I have clearly seen other things in the past that HA did not predict for me or tell me about after. I am one of about 20 hobbyists who specialize in finding and keeping track of objects like USA 193. Heavens-Above uses our orbital elements, but for some reason, does not have the standard magnitude for this one, which is required to predict approximate magnitude. So, you can run predictions if you specify the object, but it will not come up in the general predictions for bright satellites. Unfortunate, because it is a bright object. I will alert H-A to the correct std mag. Thanks for your help. My pleasure. Ted Molczan |
#7
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Triple Spacecraft Sighting
wrote in message
ups.com... I am one of about 20 hobbyists who specialize in finding and keeping track of objects like USA 193. Cool! That sounds fun. At least, it sounds for for YOU to do it because I understand there's a lot of stuff up there. But I guess if it keeps you looking up, it can't be bad. Thanks again. Jim |
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