Showing posts with label USA 129. Show all posts
Showing posts with label USA 129. Show all posts

Saturday, 21 April 2007

Timing errors and a mag. -5 IGS 1B flare

After the unexpected METOP-A flare of yesterday evening, I was surprised by another unexpected flare. And what a flare: it concerned the failed Japanese radar satellite IGS 1B (03-009B) flaring at about 21:06:20 UTC to magnitude -5!

It happened after I had taken a photograph of IGS 1B and was in the process of moving my tripod to another corner of the courtyard. I suddenly saw it flaring so brilliantly with a distinct yellowish colour and my jaw dropped. I didn't get the chance to aim and get a shot of it.

I have never seen IGS 1B do this before. Together with the somewhat irregular brightness behaviour in past evening sightings, I think it underlines that it is tumbling out of control.

On a less positive note, I seem to have developed a time lag in my positions lately. They seem to be about 0.35 seconds too late in general. All positions produced from now on will incorporate a 0.35s correction therefore and we'll see whether things get in line again.

The most likely source of the timing error is in the camera (another much less likely option is in the DCF77 signal). Indeed I recently did access my camera with other software than usual, which seems to have done something to my settings.

The timing accuracy keeps being a head-ache and the bottle-neck of the technique I employ, together with the effects of random noise (and the noise suppression routine) in the image.

Yet for now my current equipment is all I can afford, so I'll just have to do with it.

Below is another image of yesterday, showing Keyhole USA 129 (96-072A) crossing at mag. +1 close to the coma cluster (here shown at reduced resolution, so some of the fainter stars are lost).

(click image to enlarge)

Friday, 20 April 2007

Bonus flare of unknown (=Metop-A) with USA 129 (UPDATED)

"Something" just produced a fine mag. -1.5 flare only a few degrees from USA 129. I have not identified the flaring object yet. I could see the two cruise up with each other on roughly parallel tracks, a few degrees apart, USA 129 at +2.5, in Ursa Major. The flarer was leading and produced the flare at 20:12:10 UTC. See image below. The fainter trail is USA 129.

USA 129 itself (I believe) produced a flare of mag. 0 low in the east at about 20:11:00 and remained bright for tens of seconds after that. I catched it still being +1 some 20 seconds later.

More later, including (I hope) the flarer ID after I have measured the image and have dan an ID run with the positions.

Update: the flaring object is identified as Metop-A, 06-044A. With thanks to Russell Eberst and Arnold Barmettler.

(click image to enlarge)

Thursday, 19 April 2007

Flare Galore! And IGS 1B tumbling?

Flare Galore this evening! Three objects were observed flaring: keyholes USA 186 (05-042A), USA 129 (96-072A), and Lacrosse 4 (00-047A).

The USA 186 flare was spectacular, see the image below. It was a complex double flare. First it very slowly flared to mag. -1.5, peaking round about 20:53:00 UTC. When it was still fading from that flare, a second very short flare was seen at about 20:53:11 UTC. This flare terminated very suddenly, the sat becoming faint in an instance.

Below image shows it all. The peak of the first -1.5 flare coincides more or less with start of the exposure and is at down left (movement is from down left to upper right). The second flare can be seen at upper right. It ended very abruptly with the sat going to naked eye near-invisibility almost at an instance. update (19/04/07): the faint trail extension I thought was real, turns out to be an image artifact.

(click images to enlarge)



Shortly after this, USA 129 flared as well, albeit more modest than USA 186 ten minutes earlier. It reached about mag. +1 at 21:03:30 UTC. The image below shows it fading directly after the flare peak.

(click image to enlarge)


The third flare of this night was produced by Lacrosse 4, and predicted to me by Philip Masding. His prediction was for 21:37:34 UTC: it flared at 21:37:37 UTC. It was a modest flare only. The image is below, the brightness modestly peaks in the second part of the trail.

(click image to enlarge)


This evening I finally successfully observed and captured IGS 1B (03-009B), the Japanese radar satellite that recently reportedly failed. It made a shadow exit at 23:52:50 UTC and was of mag. +2 immediately following that. In the next minute it slowly, irregularly but clearly varied in brightness with an amplitude of about 0.5 to 1 magnitude.

This is quite unlike its steady brighness in past years, so it appears that after the power failure its attitude is now out of control and it is tumbling.

In the image below it is fading, shortly after the end of the exposure it shortly gained brightness again.

(click image to enlarge)


In addition to this all I also watched and photographed a fine pass of the International Space Station around 20:32 UTC, and spotted and photographed a bright stray object near 20:51 UTC while waiting for USA 186: I still have to identify this object as I have not measured that image yet.

Wednesday, 11 April 2007

USA 129: 0.6s early and bright

USA 129 (96-072A) flared again to mag. -1 at about 19:56:50 UTC in the bum of Leo. It was some 0.6s early, so it looks like no manoeuvre yet. On the 9th perigee of the satellite coincided with equator crossing, which is usually the moment KH's manoeuvre.

Below image started some 10 seconds after the flare peak and shows USA 129 still bright, fading from +1 to +2, between Leo's bum and the coma cluster.

(click image to enlarge)

Monday, 9 April 2007

Chasing Keyholes

The past two evenings where very clear again. I spent them chasing Keyholes and Lacrosses.

USA 129 (96-072A) and USA 186 (05-042A) provided some nice flares again. On Saturday the 7th, USA 129 displayed a slow -1 flare at 20:01:00 UTC, and a +2 flare very low in the west during the second pass at 21:38:40. The next evening, its cousin USA 186 flared to mag. 0 at 20:22:30 UTC in pretty much the same local sky area as USA 129 did the previous evening. In both cases they peaked in brightness before my first exposure started, and I catched them fading again (see image below).

I also obtained my first point on the Japanese radar sat IGS 1B (03-009B) since its reported failure. It came out of eclipse just above the rooftops, the trail on the image is still faint and hence I am not too confident in the single position I obtained.

In the next few weeks, moving away from spring equinox, the IGS-es will come higher and higher in the sky. There is a new set of recently launched IGS objects I hope to start tracking besides IGS 1B.

As usual the Lacrosses were covered again too. Lacrosse 5 (05-016A) did its "disappearance trick" again on the 7th at 19:30:17 UTC. The other Lacrosse target was Lacrosse 2 (91-017A).

For yesterday evening, I had USA 129 less than 0.1 s "late", but clearly off-track by 0.08 degree. USA 186 was as much as 0.9s late but on-track. Lacrosse 2 was less than 0.1s "early" and on-track.

The image below shows USA 129 (96-072A) some 15 seconds after a flare peak, still being mag. +2, crossing near the Coma cluster on the 7th.

(click image to enlarge)

Wednesday, 28 March 2007

Another case of identity confusement

It must be in the air or something, but yesterday evening I again mixed up two satellites, and again it involved USA 186.

This time, I observed a magnitude zero flare in the zenith at 20:35:10 UTC and mistakenly reported it to the Seesat list as being a flare of USA 186 (05-042A).

In reality, it was another Keyhole, USA 129 (96-072A). USA 186 would pass 10 minutes later along a similar track...

It shows up on two images (both taken after the flare) and yielded 4 positions, the last of which is probably in error.

I also covered two passes of Lacrosse 5 (05-016A). The first pass was a twilight pass and Lacrosse 5 remained "hidden" most of that pass, except for a brief period of maybe 30 seconds after 19:14:10 UTC, when it suddenly appeared just east of Polaris at about mag. +2.5. Lutz reported it was gone again by 19:14:47 UTC.

The second pass saw no disappearance event. Lacrosse 5 was bright and steady, and four photographs yielded 8 positions.

With regard to the night previous to this, I can add a few things. First the confusion between Keyhole USA 186 and the weathersatellite NOAA 14 when the latter was producing a brilliant flare. As can be seen from the following diagram, the two were indeed cruising up very closely at that time, hence why they were so easily confused. At the time of the bright flare which I captured on photograph, they were only 8 degrees apart in azimuth and 0.2 degrees in elevation.

(click diagram to enlarge)


In addition, I can also report that I obtained positions on USA 129 and Lacrosse 5 that night.

Monday, 12 March 2007

Lacrosse 2 running early

Lacrosse 2 (91-017A), the oldest in the Lacrosse (Onyx) SAR-satellite series still in orbit, is running increasingly early. Yesterday evening it already was over 7 seconds early and clearly off-track relative to a 4 day old elset. Is it going down for a de-orbit?

Yesterday evening saw very clear skies. I gathered a nice batch of data: two images (4 positions) on Lacrosse 2 (91-017A), two images (4 positions) on Lacrosse 3 (97-064A), and three images (6 positions) on USA 129 (96-072A). Plus in addition to this, I catched a stray in one of the Lacrosse 3 images, which turned out to be a 22-year-old Russian rocket booster, Kosmos 1689 Rk (85-090B, #16111).

Below is one of the three images I shot of USA 129.

This evening I skipped tracking activities. I am not feeling well and decided to take some rest instead.


(click image to enlarge)

Saturday, 10 March 2007

Flaring Keyhole USA 129

There was cirrus in the sky in daytime, persisting after sunset. Only after 9 pm local time, the sky had cleared enough from haze to attempt photography. This left only one target, USA 129 (96-072A, #24680), a Keyhole imaging satellite.

It made a zenith-pass near 20:21 UTC during which it put on a spectacular show.

As it cleared the edge of the roof and came into my view in the zenith, it was very bright and clearly flaring. It must have been around mag. 0 to -1, peaking near or before 20:21:20 UTC. When my camera opened it was already past peak brightness for several seconds but still bright, gradualy fading. The image is below.

Obtained two positions from the image. My timings suggest it was 1.15s early with regard to elset 07066.85705303

(click image to enlarge)

A Keyhole and two Lacrosses

Another clear evening last night. I managed to catch one KH and two Lacrosses.

The KH was USA 129 (96-072A). It appears as two rather faint trails on two images: the starting point on the first trail is behind the building. I have it running 0.7s early relative to a 2-day-old elset. I obtained 3 positions

Lacrosse 2 (91-017A) was as much as 1.5s early and 0.1 degree off in cross-track relative to a similar aged elset. I obtained 3 positions.

Lacrosse 3 (97-064A) by contrast was pretty much on-time and on-track. It made a nice bright trail. It briefly and modestly flared up to maybe +1.5 at about 19:49:45 UTC, just before shadow entry. I obtained 2 positions.