The Lacrosse 5 "disappearance trick", and a BWGS meeting

On Saturday 26 September, a small number of BWGS satellite observers gathered at the house-boat of Leo Barhorst (Cospar 4253) at Almere. Present were, besides Leo Barhorst, BWGS president Bram Dorreman and me. A number of active BWGS observers alas could not come, hence the rather small group this time.

In the afternoon we exchanged some information, looked at some software, my collection of "black space program" mission, launch and unit patches, and Leo's collection of space-related postal stamps. I demonstrated how I astrometrically measure my satellite photographs for positions, and how I get brightness curves from an image.

The plan was to try some joint observations that evening (we could stay for the night at Leo's boat), and as it was sunny, we started preparations in the early evening. I took below photograph of Leo (seen frontal) and Bram (seen on the back) while they were making their preparations

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The sky was not perfect (and would progressively deteriorate later that evening). From a small green a few tens of yards from Leo's boat, we started by watching Iridium 80 flare to mag. -3.5 close to epsilon Cyg in the eastern wingtip of Cygnus. I took the picture below, a 10-second exposure with the EF 100/2.8 Macro USM:

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Immediately after that I rushed to re-aim the camera and capture the USA 144 decoy (99-028C) passing close to vega in the next minute. Predictions had put the track just west of Vega, and while Bram and Leo were watching there with binoculars I made a series of images. Strangely enough, Bram and leo did not pick it up: and the reason was, after a look at my photographs, that it passed east of Vega, not west! After a puzzled "huh?!?" it dawned upon me: the coordinates of my prediction software were still set on my Leiden locality!

Next up were the objects related to the recent launch of a Russian Meteor weather satellite. Bram and Leo indeed picked one up with their binoculars.

Shortly after that, we watched a nice pass of the SAR Lacrosse 5 (05-016A) with the naked eye. As we watched it, it did it's infamous "disappearance trick" again. It did so during an exposure, that captured the quick loss of brightness very well. It was the first time I imaged the phenomena with my Canon EOS 450 DSLR. It yielded this very nice diagram of the brightness variation (constructed from two images):

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Note how quick the brightness drop is (it takes a mere 4 seconds) and how sharp the turnpoints in the diagram are.

Next up were passes of the KH-12 optical reconnaisance Keyhole USA 186 (05-042A), which briefly attained naked eye visibility and was of course photographed; and the NOSS 3-3 duo (05-004A & C) which were faintly visible to the naked eye as they crossed Cygnus, and yielded two very fine pictures, one of which is below:

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Note the difference in brightness between the A and C components. (note: I mistakenly labelled the C component as 'B' in the image...)

After this, Leo and Bram observed the NOSS 3-3 rocket, which is a flasher. As the sky quality rapidly deteriorated, we called it quits after that and went inside to reduce the observational data.

It was nice to meet and observe together. Leo was a perfect host, and his cat Bankie kept my feet warm later that night.

USA 184 Trumpet (?) ELINT and more

Yesterday in the daytime, it was clouded and rainy. It cleared marvelously in the evning though. I detected the clearings too late to capture the evening Keyhole passes, but captured a number of other objects: IGS 1B (03-009B, a defunct Japanese SAR), Lacrosse 2 (91-017A, a SAR as well), the NOSS 3-3 Duo (05-004 A & B), and two HEO objects: USA 184 (06-027A) and the USA 144 decoy (99-028C) again.

The image below shows the USA 144 decoy again, and is a somewhat better picture than that which I posted in a previous post:

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USA 184 was imaged as well, and for the first time by me. It showed up bright. It is probably a Trumpet-class ELINT satellite. It is in a Molniya orbit (see below) and at the time of imaging was at an altitude of 28560 km, over Northern Europe.

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Below is one of the images, plus an animated GIF of all five images, showing the movement perpendicular to the night sky rotation:

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NOSS-es, Lacrosses and ISS

Yesterday evening the 9th it was clear in twilight, but clouds came in a while later. Nevetheless there was time enough to get out the ETX-70 again and bag the NOSS 3-4 duo (07-027A and 07-027C), the NOSS 3-3 duo (05-004A and 05-004C) and Lacrosse 3 (97-064A). In total, 7 points were obtained. In the morning of the 10th, I observed the International Space Station just before clouds again interfered.

About 3 minutes before the NOSS 3-4 duo pass, another faint sat crossed the telescope field in a similar trajectory. I was just making a last check of the star field in view against a plotted map to ensure I had the correct location in view, so hadn't the stopwatch in my hands. At first I was a bit worried it was one of the 07-027 objects but very early, so I was relieved when 3 minutes later the real 07-027A sailed into the FOV.

Later that night it cleared again. Below is the image of the ISS I shot a few hours later, during the morning hours. It can be seen passing from Corona borealis into Hercules. It was bright, around mag. -4. My main intended target for that early morning was Progress M-61, but clouds (already visible in the ISS image) intervened.

(click image to enlarge)