The orbit of USA 245 and the current KH-11 constellation

In the past two weeks (e.g. here, here and here) I have written about tracking USA 245 (2013-043A), the new KH-11 Keyhole (Evolved Enhanced CRYSTAL) optical reconnaissance satellite launched as NROL-65 on August 28.

USA 245 has been launched in the same orbital plane as USA 186 (2005-042A), a KH-11 Keyhole launched on 19 October 2005. In time, it is therefore probably intended to replace this satellite.

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The diagram above (made with JSatTrak and using our amateur derived orbits for the two satellites) shows the orbital similarity between USA 186 and USA 245. The orbital plane is the same and the orbital altitudes are similar (and will probably be even more similar in the future, after more USA 245 orbital manoeuvering). USA 245 (white) is currently in a 262 x 1010 km, 97.87 degree inclined orbit. USA 186 (green) is in a 263 x 1017, 97.93 degree inclined orbit.

The constellation of on-orbit KH-11 Keyholes now counts five satellites:

USA 129  (1996-072A)
USA 161  (2001-044A)
USA 186  (2005-042A)
USA 224  (2011-002A)
USA 245  (2013-043A)

These operate in two rather loose orbital planes. One, sometimes called the "West plane", produces passes in the local evening and morning, around 10 am and 9 pm local time. To this plane belong USA 129, USA 186 and the new USA 245. The other plane, sometimes called the "East plane", produces passes one to two hours after local noon and local midnight, around 1 am and 2 pm local time. This plane is occupied by USA 224 and USA 161.

The orbits of all the Keyholes currently in orbit are pictured below, with the two orbital planes well visible left and right of the center meridian:

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Of the Keyholes still in orbit and presumably operational (as they are periodically reboosted to maintain their operational configuration), USA 129, launched on 20 December 1996, has been on orbit for almost 17 years now. As can be seen in this table of data compiled by Ted Molczan, this is the longest operational lifetime of any of the KH-11 Keyholes so far. It will be interesting to see how long they will keep it flying: it's last predecessor, USA 116 (1995-066A), was de-orbitted on 19 October 2008.

With the optical component of the FIA program cancelled, I suspect all of the remaining post-1996 Keyholes to remain operational for many years. For USA 129 though, the end should come one of these days, perhaps once USA 245 has been fully checked out and is put on operational status.

(note added 14 Sep 2013: this post has a long follow-up post here, detailing past configurations of the KH-11/CRYSTAL constellation, and how I expect to see the satellite configuration re-arranged early 2014, when USA 245 becomes fully operational)

SAR Lupe 4 and USA 129 (pass footage)

Like a few days ago, I used the WATEC 902H video camera  yesterday evening to film a pass of  USA 129.

Near 19:41:30 UTC (21 March), the same 10-degree wide FOV first saw the German military Radar satellite SAR Lupe 4 (08-014A) pass and then, only some 10 seconds later, the American KH-12 Keyhole optical reconnaissance satellite USA 129 (96-072A). Below is the resulting footage:



The FOV is about 10 degrees wide, and the two brightest stars are delta and gamma Uma in the Big Dipper. The lens used was a Canon EF 2.0/35mm lens. The camera is a WATEC 902H. Time insert is done by a GPS time inserter.

Footage of a pass of the KH-12 Keyhole optical reconnaissance satellite USA 129

Spring is a time when not only some birds appear out of their winter hiding, but some satellites emerge from winter darkness as well. Among them the evening plane KH-12 "Improved Crystal" Keyhole satellites.

The footage above shows one of these evening plane KH-12 Keyholes, USA 129 (96-072A), the oldest one still in orbit. The footage was shot by me in the evening of Monday 19 March, from my observatory in Leiden. The star field is a part of the tail of the Big Dipper: epsilon Uma at lower left and delta Uma at upper left. A WATEC 902H camera, GPS time inserter and Canon EF 2.0/35mm lens were used.

USA 129 was quite bright during this pass and well visible by the naked eye: initially near magnitude zero in Leo, then near magnitude +2.5 once culminating near Uma (the segment of footage shows it while it was near +2.5.)

The Keyholes are optical reconnaissance satellites, resembling Hubble Space Telescopes pointing to Earth surface. They image the earth with a resolution that is believed to be in the order of 10 centimeters (about 4 inch). Four of them are in orbit currently: USA 129 imaged above, USA 161, USA 186 and USA 224. USA 186 is an evening plane Keyhole just like USA 129: the other two are midnight plane Keyholes. On my 52 degree latitude, the evening plane Keyholes start to make visible evening passes in March, the midnight plane Keyholes during the late spring and summer (starting April-May).

Topex/Poseidon flaring

Monday evening was clear. I targetted the KH-12 Keyhole USA 129 - it is expected to manoeuvre one of these days.

While watching it (and photographing it), a bright mag. +0.5 flash occurred close to it, followed by another one and than a longer +1.5 flare. It turned out to be the malfunctioned US-French Oceanographic satellite Topex/Poseidon (92-052A), which I have observed flashing before. It malfunctioned in 2006 and since has started to tumble.

Below is the image showing both USA 129 and Topex/Poseidon, the latter showing the three flares:

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The image yields this brightness curve, with peaks (two narrow and one broad) spaced 3.6 seconds apart:

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USA 161 new orbit finally established

The saga earlier covered here and here is finally coming to an end: it seems that the KH-12 keyhole USA 161 now no longer is escaping our detection.

The reboost on August 24 has provided our observer's and analysts corps with quite a challenge. After initial failures to recover it, the satellite was detected by several observers (including me) for a number of times in the early days of September. But in each case it was subsequently lost again and each new preliminary orbit solution put forward seemed to be wrong (see the two posts linked above in the introduction). Analysts were in despair, and observers confused.

Then Ted finally found a solution which seemed to agree with all observations and asked observers to search according to this search orbit early this week. Following this, Scott Tilley in the USA indeed recovered the object in a position much as predicted by Ted's solution, with Russell Eberst in Scotland following suit.

The now established orbit is quite different from the earlier search orbits. Instead of the perigee having  been raised, it turns out that it has been lowered, with the perigee 40 km lower and apogee 120 km lowered.

USA 161 playing hide-and-seek with observers

A few days ago, I wrote about the effort to recover the KH-12 Keyhole optical reconnaissance satellite USA 161 (01-044A). After it went "missing" following August 24, and not everybody bought into the opinion that it was de-orbitted, it was recovered in the first days of September by an effort of several observers, including Pierre Neirinck and me. It had made a massive orbital manoeuvre (for more details, read here).

Following Pierre Neirinck's and my positive observation on September 1-2 already reported earlier, Björn Gimmle in Norway as well as Pierre and I failed to see it on the night of September 2-3. This could (in the case of Pierre and me) however have been due to unfavourable observing conditions at both our localities in France and the Netherlands.

Next Russell Eberst in Scotland  observed it again on September 3-4. However, on subsequent orbits it definitely got lost again. Scott Tilley in the US could not find it on September 5 and neither could Pierre Neirinck in France (I had meanwhile dropped out of the chase due to bad weather).

Next, Scott Tilley positively observed it on September 6th in an orbital position definitely out of sync with Pierre and my observations from September 1-2. This indicated that USA 161 made yet another major manoeuvre around the time of Russell's September 3-4 observation.

The situation now had gotten very confusing, with one of the analysts trying to solve the discrepancies by suggesting that Russell's observation was not USA 161 but a random stray. This is unlikely though, as any object in LEO big enough to be mistaken for USA 161 is catalogued, and Russell's object did not match any of these known catalogued objects. Moreover, as another analyst remarked, the solution to exclude Russell's observation and link our September 2-3 observations with Scott's September 6 observation, would yield very unrealistic drag parameters.

It got even more confusing for a short while, when Italian observer Alberto Rango reported a possible observation on 6-7 September, but with hesitation as he wasn't too sure. In this case, it quickly turned out to be a stray, ironically the French optical reconnaissance satellite Spot 2.

So, for the moment we have lost USA 161 again. Our observer's corps is now trying to search according to a number of possible orbital solutions, most of them no more than educated guesses. I am confident that given time, it will be found again. Given that the weather has turned bad and that the advancing winter is quickly diminishing my midnight window for USA 161 (it can now only be seen low in the north, where I have horizon obstruction), I think I am out of the chase however.

USA 161: "The reports of my death are greatly exaggerated..."

KH-12 Keyhole USA 161 (01-044A) is alive! Pierre Neirinck and I observed it last night around 23:55 UTC (1 Sept). Below is one of the two images of it which I captured:

click image to enlarge

The Keyhole, launched from Vandenbergh on 5 October 2001, went AWOL on or short after 24 August, with several observers failing to observe it in a window well around its last orbital position after that date. This lead to some suggestions, covered earlier here, that it could have been de-orbitted. After all, a new Keyhole, USA 224 (11-002A) had been launched in the same orbital plane on January 20, 2011, ostensibly as a replacement for USA 161.

Not everybody took to the idea of a de-orbit for USA 161 though. It's much older sister ship in the evening plane, USA 129 (96-072A), was after all still active even though USA 186 (05-042A) had been placed in the same orbital plane in 2005. So why de-orbit the newer USA 161 but leave the much older (and presumably less modern) USA 129 up?

The alternative to a de-orbit, was a massive reboost into a different orbit. This option got more credibility when an anonymous radio observer reported the possible reception of a radiosignal from USA 161 on August 26. Based on this possible reception, Ted Molczan dispatched a number of search orbits to the active observers, and the hunt for Red October USA 161 was on...

Skies were overcast in Leiden at that time, but on 28-29 August it cleared somewhat (with the emphasis on "somewhat"). I tried to cover the nominal plane of the search orbits that night (which meant staying up late to 2 am local time) under conditions that can only be described as abominable (thin and sometimes thicker clouds) but failed to recover the satellite. That could easily have been due to the conditions though. In France, Pierre Neirinck suffered the same conditions.

On the night of 30-31 August, Pierre Neirinck in France spotted an object that could be USA 161 near 00:17 UTC. As his sky suffered from clouds, there was some uncertainty in the position he obtained. His observation suggested that the satellite was moving in an orbital plane that was shifted slightly more eastwards than the plane of the search orbits.

On the night of August 31-September 1, Björn Gimmle in Norway possibly observed it again near 23:20 UTC, but he wasn't too sure. Pierre Neirinck observing from France between 22:58-23:23 UTC did not see it. Neither did I, keeping (under good sky conditions) a visual and photographic watch between 23:31-23:46 UTC. Red October USA 161 turned out to be elusive and not willing to give up it's location easily!

Third time is a charm however (or, as we say in Dutch: Drie maal is Scheepsrecht, which is ambiguous to translate beacuse the exact meaning of "scheepsrecht" is under dispute: but it is something like "Three times is Ship's Justice" or "Three times is Alderman's Justice").

On the night of September 1-2, both Pierre in France and I in the Netherlands observed it unequivocally around 23:55 UTC. Keeping a visual and photographic watch under good conditions, I picked it up visually somewhat east of Polaris and under Cassiopeia, and just under the FOV of my camera. I quickly re-aimed and shot two images (one of them shown above), yielding four points. It was steady and at its brightest about mag. +2, a naked eye object. At the same time, Pierre in France also saw it visually and got three points.

With these data of last night, the new orbit is starting to get a bit of shape - probably enough for others to recover it more easily the coming nights. Probably not here at Leiden though: the sky has grown very hazy today (thin clouds) and I need some sleep.

The very preliminary orbit still needs more observations before it becomes accurate, but it looks like the perigee has been significantly raised to twice the altitude it was (from 303 km to ~590 km), and apogee slightly lowered (from 911 km to ~780 km).

These kind of situations, where a satellite makes a big manoeuvre and the hunt is on to recover it, are always exciting times where the hobby gets most fun!

KH-12 USA 161 de-orbited? [updated 02/09/2011]

UPDATE 2 Sept 2011: USA 161 is Still Alive! It has not been deorbitted but made a large manoeuvre. Read more about the recovery here.

Negative observations on Wednesday and Thursday 24-25 and 25-26 August reported by Russell Eberst from Scotland on SeeSat-L and Pierre Neirinck from France (priv. com) suggest that the KH-12 Keyhole USA 161 (2001-044A), an advanced high resolution optical reconnaisance satellite launched on 5 October 2001, has either undergone a large manoeuvre or (more likely) has been de-orbited last week.

Earlier this year (January 20, 2011), USA 224 (2011-002A) was launched as NROL-49 and put in the same orbital plane as USA 161, probably as a replacement for the latter.

Below are two archive pictures I shot of USA 161 brightly flaring twice on 30 July 2009:

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The remaining KH-12 constellation (if indeed USA 161 has been de-orbitted last week) now consists of three satellites: USA 129 (96-072A), USA 186 (05-042A) and USA 224 (2011-002A), the oldest of which (USA 129) is now 15 years in service.

USA 224 which replaced USA 161 represents the noon and midnight plane. USA 129 and USA 186 represent the morning and evening plane. Below diagram shows the satellite constellation as it is now USA 161 has presumably been de-orbitted:

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Satellites far and near

Both Friday and Saturday evening were very clear, and the moon not yet a nuisance untill midnight.

On Friday I targetted both a few LEO and HEO objects. The KH-12 Keyhole USA 129 (96-072A), the SAR Lacrosse 3 (97-064A) and the FIA Radar 1 (10-046A) were observed, although a misalignment of the camera in the case of FIA R1 resulted in only one point on the latter. As I was waiting for FIA R1 to pass, the International Space Station (ISS) made a majestic, very bright zenith pass.

Next I changed the EF 2.5/50mm lens for the Carl Zeiss Jena Sonnar MC 2.8/180mm, and targetted two faint and distant HEO objects, The Trumpet ELINT and SBIRS platform USA 200 (08-010A) and the SDS 3-4 data communications satellite USA 179 (04-034A). Two images of both are shown below.

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While sleeping, the G68 Sierra Stars Observatory Telescope in California made images for me that resulted in a position on the enigmatic Prowler (90-097E).

Saturday evening was clear as well. This time, I only targetted LEO objects: the Japanese malfunctioned satellite IGS 1B (03-009B), and both the KH-12 USA 129 and the FIA Radar 1 again.

As I was observing, a group of people attending a birthday party of one of the neighbours came onto the courtyard for a smoke. Curious, they asked me what I was doing, and after a short explanation from my part, the group of six watched in an excited state when IGS 1B made a very bright pass. It was easily visible naked eye, and they all saw it.

Below is one of the images from this evening: the FIA Radar 1 (10-046A) passing through Lyra (brightest star is Vega).

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More flashing NanoSail-D, and flaring KH-12 USA 224

A week after my May 24 observations, I observed NanoSail-D (2010-062L) again, the experimental NASA solar sail.

NanoSail-D (image: NASA/MSFC)

As a week ago, it became very bright after culmination, while descending in the south, and was rapidly flashing again. It was easily seen by the naked eye, reaching mag. +1 or possibly +0.5.

In fact it is so bright, that the pixel brightness of the trail reached saturation on two of the three images. The first image (below) did yield brightness information: the resulting curve is shown beneath it. The flash period is irregular, but periods of 0.5s and 1.0s pop up frequently in the diagram (for actual determined flash times, see here. Astrometry on the satellite itself can be found here).

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As can be seen on the images, the satellite was in a race with an untimely field of clouds (the orangish streaks in the images), staying just ahead of it. Visually, the brightness fluctuation was much more apparent than it is on these images (due to the saturation of the latter): it was very clearly flashing.

Nanosail-D was not the only object flashing. USA 224 (11-002A), the new KH-12 Keyhole launched on January 20 this year, flared too, while passing through the zenith, with flares at 23:48:27.3 and 23:48:31.8 UTC (May 31). The "saddle" and elevated brightness between the two flares is interesting (the trail is notably fainter before the first flash, and subsequent images show it is fainter again after the second flash):

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This was the second time I imaged USA 224 (The first time was May 24). In addition to USA 224 and NanoSail, I also imaged another KH-12 Keyhole, USA 161 (01-044A), and a Lacrosse SAR, Lacrosse 3 (97-064A).

KH-12 USA 129 flaring: and IGS 1B again

A period of sunny weather commenced the past week, albeit with a trend towards increasing hazyness. I observed on the 19th, 20th and 21st of April, targets being the evening KH-12's USA 129 (96-072A) and USA 186 (05-042A), as well as IGS 1B (03-009B). An attempt to locate the geostationary satellite Mentor 2 (98-029A) on the 20th failed, probably because of the poor observing conditions.

Yesterday evening (21st April) the sky was quite hazy with, during twilight, abundant whisps of thin clouds. USA 129 (96-072A) slowly flared to mag. 0 at about 19:56:15 UTC, and the resulting picture of the flare amidst thin clouds in a still bluish twilight sky, looks very eerie:

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Some what later, I made this shot of IGS 1B (03-009B) gracefully sailing through Bootes:

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My story about the re-entry of the above pictured malfunctioned IGS 1B satellite in about a year from now, has been picked up, notably after Jim Oberg reposted it on the NASA Spaceflight Forum here. Two journalists contacted me with questions, and my post itself attracted some US Government attention (when the Executive Office of the President visits your weblog, you know it is being taken serious). So I guess some people have woken up now, and hopefully we will soon see a serious risk assessment and more pertinent information by the Japanese as to the tank content of the satellite.

Bright and fast KH-12 USA 129 zapping through perigee

Yesterday evening was clear, and I observed the KH-12 Keyholes USA 129 (96-072A) , USA 186 (05-042A) as well as the SAR satellite Lacrosse 3 (97-064A).

USA 129 was making a pass at 40 degree altitude in the east, at an altitude of only 303 km only minutes from passing through perigee. As a result, it was bright and very fast, zipping through the sky at notable speed: very cool to watch. It resulted in two long bright trails on the images. Two strays were captured as well: a very faint Russian rocket stage (84-067B) in one image, and a brighter Russian rocket stage (Kosmos 1484 r, 83-075B) in the second. The latter cruised up parallel to USA 129, being overtaken by it when both were passing through the tail of the Big Dipper. See the image below, where the longer brighter trail (the lower one of the two) is USA 129, the other the Russian rocket stage:

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KH-12 USA 186 passed through the same sky area 20 minutes later, but at a much different altitude (830 km, against only 303 km for USA 129). The clear difference in trail length this generates, is shown by the image below, which is a stack of the two images of 19:41 and 20:03 UTC:

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Again the FIA Radar 1 (NROL-41)

Last night was frosty and very, very clear. In the evening, I took pictures of the KH-12 USA 129 (96-072A), the HEO SDS 3-4 USA 179 (04-034A) and the geostationary ELINT USA 202/Mentor 4 (09-001A), low over the southeastern horizon. At the time of observation, it was some 4 degrees south of Jupiter.

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I took a quick shot at Jupiter too with the Carl Zeiss Sonnar MC 2.8/180, to capture the moons of Jupiter. Here is the image, at 100% pixel resolution:

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In the early morning, at 5:18 am local time, I watched and photographed a very fine pass of the FIA Radar 1 (10-046A) again. It attained a maximum brightness of +3.5 while crossing through Cassiopeia. Below is an image, showing the 'W' of Cassiopeia and the FIA Radar 1 trail (movement is from top to bottom).

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Spectacular Keyhole appearances

The KH-12 Keyholes USA 129 (96-072A) and USA 186 (05-042A) delivered some spectacular views in the early part of September.

USA 129 was making passes over Europe near its perigee, at no more than 300-310 km altitude. That is lower than the ISS! It resulted in a zipping fast speed, especially during zenith transits. It was very bright too, attaining magnitude +0 easily.

Below are two images of two such spectacular passes. One (3 Sept 2010) shows it in twilight low in the eastern sky, grazing the roof of my neighbours, at a distance to the observer of 800 km and an orbital altitude of only 305 km. The other image (5 sept 2010) shows it during a zenith pass, when it was at only 300 km orbital altitude at a distance to the observer of no more than 305 km! As can be seen, the FOV of my EF 2.5/50mm (about 24 x 18 degrees) was no longer adequate at that time! (the image shows the full frame: movement is from bottom to top).

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Below diagram shows the geometry in question for the second image (based on elset 10248.82329557). The photograph was taken 30 seconds after perigee: during perigee itself, it could not be photographed as it coincided in time with emergence from the Earth's shadow.

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A few nights later, USA 186 flared brightly to mag. +0 on September 9th at 21:15:10.7 UTC, yielding this nice picture plus brightness diagram (movement is from left to right):

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click diagram to enlarge

Manoeuvring KeyHoles and the flashing Iridium 33 wreckage

July 2010 so far yielded a nice series of clear evenings, due to very warm, sunny weather (in most cases allowing observations in shorts and shirt). I observed on July 3, 4, 6, 12, 15, 16, 17 18, 19 and 22.

Two manoeuvring KeyHoles

Prime targets this month were the KH-12 KeyHoles USA 186 (05-042A) and USA 161 (01-044A). These both manoeuvred on the 14th of July, giving us observers a nice task of recovery and renewed tracking.

The manoeuvre of USA 186 (05-042A) was first noted by Pierre Neirinck in France. After some other observers missed it, he observed it being very late, but initially lost his reference points. Ted Molczan next created a number of search orbits, based on different presumed manoeuvre times. Next Alberto Rango and me again recovered the satellite (Alberto first while I still had daytime, then me on the next orbit, in deep twilight), in an orbit very close to one of Ted's search orbits.

Using pre-manoeuvre and post-manoevre orbits calculated by Ted Molczan from our observations, the manoeuvre occurred on July 14th at the ascending equator crossing at about 15:00 UTC, over Indonesia.

Next it turned out that another KH-12 Keyhole, USA 161 (01-044A) had also manoeuvred early on the 14th. Again, Pierre noted it first, observing it 12 minutes late on July 17th. Next Ted and a number of other observers joined the recovery (including me at some point). Using pre- and post-manoeuvre orbits calculated by Ted and Mike from our observations, the manoeuvre ocurred at the ascending equator crossing near 00:20 UTC, July 14th, near Hawaii.


The flashing behaviour of the Iridium 33 wreckage

On 10 February 2009, the American Iridium 33 (97-051C) telephone communication satellite and a defunct Russian satellite, Kosmos 2251, collided in space. A large number of debris pieces were spread over Low Earth Orbit (see here), and the main wreckages of the two objects kept orbiting, now wildly out of control.

The Iridium 33 wreckage (97-051C) made some fine passes last month, displaying the same kind of flashing behaviour due to tumbling that I also observed shortly after the collision in 2009 (see here, here and here). Some of these flashes are easy naked eye flashes, reaching mag. +0. The object interchanges bright flashes like these with (more numerous) fainter flashes in the +4 range.

I targetted the satellite wreckage several times this month to determine the flashing behaviour. In March 2009, it showed a period of 4.7 seconds. Analayses of the imagery of the past few nights, shows this has changed to about 3.1 seconds. Below is one of several images, taken on July 16th, showing a series of fainter and brighter flares:

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Below are graphic representations of the flare positions (yellow dots) observed on consecutive nights (resp 16-17, 17-18, 18-19 and 22-23 July 2010). Please note: only flares happening during photographic exposures are shown here. There were more flares, but these happened while the camera wasn't open:

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(maps made using Heavensat)

An unusual flare was captured on July 17-18, consisting of a triple flare with flares within 0.5 seconds:

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Other objects besides the KH-12 Keyholes USA 161 and USA 186, and the Iridium 33 wreckage observed last 3 weeks include:

- the geostationary objects Milstar 5, Mentor 2 and Mentor 4 (USA 202);
- the HEO objects USA 184, the USA 40 rk;
- the LEO objects Progress-M 04M, MSX, Lacrosse 5, the Lacrosse 5r, IGS 1B, the IGS 5r, USA 32, the NOSS 3-3 duo and the USA 144 decoy,;
- plus a large number of GEO and LEO strays.

I have yet to analyse the USA 144 decoy (99-028C) data from July 20 for a new tumble period determination.

-5 KeyHole flare! (May 9th observations, Part I)

Yesterday evening (9 May) I observed the most spectacular Keyhole flare I have ever seen. KH-12 USA 186 (05-042A) flared brilliantly to at least mag. -5 in a blue twilight sky, while crossing from Cvn into Uma. It yielded this Iridium-like picture:

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I cannot provide a brightness profile: for the simple reason that the trail is saturated over the full length. Peak time was about 20:34:29.4 UTC (9 May 2010).

I also observed on the 5th and 6th of May, capturing a.o. USA 186 again, as well as the IGS 5 r/b and the Molniya object USA 198.

USA 198 (07-060A) showed a clear, slow brightness variation over the 1m20s image series of 5 images, taken on May 5th, growing slowly fainter over the series:

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The data during the first 12 seconds of the diagram above, are close to saturation. Hence, the brightness variation in reality is probably more expontential than the diagram suggests.
The background readings have been taken just to the right of the trails, and are plotted to show that the change in brightness of USA 198 is not due to lens vignetting, but real.

Yet another nice USA 186 KeyHole flare

I am running behind with reporting on my observations again. After my last report, I observed again on the 22nd and 26th of April. Targets were the usual suspects: the KH-12 KeyHoles USA 129 and USA 186, and two of the IGS objects (IGS 1B, and the IGS 5 r/b).

USA 186 is giving nice flare shows again. On the 22nd, I captured one of these flares (peaking at 21:11:36.7 UTC) on photograph. The same image also has the Kosmos 1515 r/b on it as a stray. See the image below, and the brightness profile of the flare below it:

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Another Keyhole flare

Although the skies were somewhat hazy, observations were conducted on the evenings of April 15th and 16th. Targets were the various IGS objects (1B, 5A, 5r/b), the Lacrosse 5 r/b, and the KH-12 Keyholes USA 129 and USA 186.

USA 186 was so friendly as to flare in my camera image on the 16th. The flare occurred at 20:43:40.75 UTC (Apr 16). Below is the image, and the resulting profile (with saturation at the peak). The two bright stars are the front stars of the pan of the Big Dipper, alpha and beta Uma.

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Spring objects, a Keyhole manoeuvre and a flare of the IGS 5 rocket

After three weeks with cloudy and rainy weather, two consecutive evenings on a row finally allowed observations again on 4 and 5 April.

This is the time of the year that, like spring birds, some object re-appear from their winter hiding: the American KH-12 Keyholes, and the Japanese Intelligence Gathering Satellites (IGS).

Two KH-12 keyhole optical reconnaissance satellites were targetted the past two evenings: USA 129 (96-072A) and USA 186 (05-042A). USA 129 is of special interest these days, as it made a small manoeuvre early april raising it's orbit slightly. I captured it 8 seconds late relative to an early April elset on April 4th. An analysis of the pre- and post-manoeuvre elsets suggest the manoeuvre occurred on April 1st near 04:35 UTC while the satellite was passing the US west coast just after going through it's ascending node.

USA 129 flared to mag. 0 on April 5th, 20:05:08 UTC.

Below is an image of USA 129 rising through patchy thin clouds in Leo on April 4th, and it's sister craft USA 186 moving low in the east though Bootes on the same evening around the same time:

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I also got my first images of this year of the Japanese IGS, optical and radar satellites. The defunct IGS 1B (03-009B) was imaged on April 4 and 5, and flared briefly to mag. 0 at 21:21:15 UTC on April 5 with a distinct orange colour. On April 5, the IGS 5A craft (09-066A) was imaged by me for the first time.

Below is an image of IGS 1B shot on April 4th:

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I also captured the rocket from the 09-066 (IGS 5) launch: IGS 5r (09-066B). It shows flaring behaviour, as can be seen below from the photograph and the detail image, with the resulting brightness profile below that. The main brightness maximum in the image occurred at 21:44:06.9 UTC (April 5).

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