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).

click images to enlarge

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:

click image to enlarge

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.

Progress-M 04M, MSX, and Mentor 2

A long spell of very warm, sunny weather is resulting in several clear nights. Since my last observations reported here (those of June 2nd), I have been able to observe on June 3, 13, 14, 16, 17, 22, 24, 26 and 29. Objects include Progress-M 04M, Mentor 2, Mentor 4 (USA 202), USA 161, USA 32, USA 184, MSX, Milstar 5, the NOSS 3-1 duo, and the STSS Demo-1. This does not include a number of non-classified strays also captured.

USA 161 (01-044A) slowly flared to -1 at 23:58:59 UTC (24 Jun).

Below are a few pictures. First: UARS captured as a stray, flaring, on June 16th:

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Progress-M 04M on 26 and 29 June:

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Geostationary USA 202 (Mentor 4), in the trees low in the sky (altitude about 17.5 degrees):

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Mentor 2 (geostationary), MSX and a stray (HJ-1A, a Chinese Earth Observation Satellite)

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The flash period of USA 81 on June 2nd (UPDATED with February 24 results)

In my previous post I reported on a bright stroboscopic flash display by the SIGINT satellite USA 81 (92-023A) on June 2. I now had some time to analyse the images. Below are diagrams showing the brightness behaviour in the two images that captured the event.

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In the first image, the median period between succesive peaks is a very neat 0.20 seconds (average: 0.18s; modus: 0.19s). The same period also is present in the series from the second image, but with more "noise" in terms of either extra "peaks" or missing peaks. Below images shows it as diagrams of the delta time between peaks, and the deviation of these to the 0.20s period established by the first image:

click diagrams to enlarge

The results compare with similar results I obtained in February this year, which for some reason I never published on this blog. These are diagrams from my February 24, 2010 observations (two images), when it showed a series of sharp glints in the zenith, similar to those of June 2nd, with a period of ~0.41s (multiple of the 0.20s of June 2nd). Lower in the sky, it changed to a slower cycle of less sharp peaks with a period of 1.26s.

click diagrams to enlarge

The brightness behaviour hence is quite similar to that for it's older sister ship USA 32 (see here).

USA 198 brightness behaviour: a belated 2nd report

A belated report on a second instance of USA 198 (07-060A) flaring.

On May 13th I captured another one of such instances, after first capturing it on May 5th (see report here, 2nd part of that post).

On May 5th I captured it decreasing in brightness froma prominent brightness peak. This time, I captured it increasing in brightness towards a prominent peak near 21:44 UTC, with a hint of the start of a decrease later. Here is a selection of images, all spaced 1 minute apart:

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The first 11 images in the series yield the curve below (I did not include the rest of the images, as they are all saturated)

click diagram to enlarge

Both this May 13 and the earlier May 5th flaring occurred close to the moment that the sun, observer and satellite lined up, indicating it is probably due to reflection on the solar panels.

An IGS 1B flare, and Geostationary satellites again

Last evening 25-26 May was not the best of evenings: cirrus, and moonlight, plus this time of the year the sky darkens late and in fact remains in twilight all night at 52 N.

In twilight, I observed the KH-12 KeyHole USA 186 (05-042A), IGS 1B (03-009B), and Lacrosse 4 (00-047A). Short after midnight, the still flaring commercial geostationary satellite Galaxy 11 (99-071A) and the classified military geostationary satellite Milstar 5 (02-001A) were the target.

IGS 1B slowly flared to mag. -0.5 at about 21:15:48.5 UTC (May 25), while the camera was open. below photograph shows the brightnes speak, when it was cruising close to the Coma cluster:

click image to enlarge

IGS 1B is a defunct Japanese Radar Reconnaissance satellite. Since it went out of control, it is producing flares occasionally (sometimes up to mag. -3 to -5 peak brightness).

Galaxy 11 was flaring again, but is getting fainter at its peak. If my modelling is right, it might flare again in a new cycle around the 3rd week of July. Below link provides an animated GIF of last night covering 20 minutes with the geosat flaring up. Milstar 5 is in it as well, moving southward.

Link: animated GIF ( 5.5 Mb)

Around 22:10 UTC, Intelsat 802 (97-031A) briefly flares up close to Galaxy 11. It stays faint, but is visible. The single image below might help discern it:

click image to enlarge

Geostationary Galaxy 11 flaring to mag +2.5

In my post of yesterday, I reported a bright geostationary satellite flaring to naked eye brightness, observed by several Dutch and Belgian observers.

Below are my images of last night (taken with the EF 50/2.5 Macro). It shows two "stars" "too many" in Ophiuchus: a brighter one (A, vertical arrow) and a fainter one (B, flat arrow). The second image is a more detailed crop of the first, at full pixel level resolution.

click images to enlarge

The glare next to the tree in the wide field image, is due to a street lantern.

The satellite flaring to mag. +2.5 turns out to be Galaxy 11 (99-071A). It peaked near 22:18 UTC (23 May) and was visible with the naked eye at that moment, nothwithstanding it was low in the sky and I was observing from the city center.

The other object is Milstar 5 (02-001A) again. A faint trail of a non-geostationary satellite is visible as well: this turned out to be Globalstar 55 (99-049C).

Link: 2.2 MB animated GIF

Above link opens a 2.2 Mb animated gif with images from 22:10 to 22:19 UTC, which shows Galaxy 11 increasing in brightness. Milstar 5 is slowly drifting south.

A third geosat was captured on the images (not shown here), which is either Thuraya 2 (03-026A) or USA 202 (09-001A); probably the first.

Two naked eye flaring Geosynchronous sats

Dutch meteor observer Peter van Leuteren contacted me this week as he had a strange bright stationary object on images of his photographic all-sky meteor fireball camera, appearing in Ophiuchus at around 22:18 UTC on 3 consecutive nights. The same object was also noted visually, at mag. about +2.5, by BWGS chairman Bram Dorreman. It was evidently a brightly flaring geosynchonous satellite.

After an alert on Dutch and Belgian astronomy mailing lists, several observers noted it as well.

I took images last night (22 May, 22:13 - 22:25 UTC) in hopes of catching it and identifying it from the position. I used the Canon 450D with the EF 50/2.5 Macro for that purpose.

Unfortunately, as it later turned out, "the" mystery geosat (for now) was hidden just behind some tree branches for me. A few degrees west of it, I however captured a second flaring geosat!

That one has now been identified by Bram and me, based on my photographic positions, as Milstar 5 (2001-001A, #27168). I have made a movie out of 13 images (10 second exposures) spaced one minute each. It can be seen here (1.4 Mb animated GIF)

The FOV of the movie is a small crop from the images, at full pixel level. The object is moving southwards at about 55"/minute.

-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:

click image to enlarge

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:

click images to enlarge

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:

click images to enlarge

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.

click images to enlarge

Satellite rush hour

Over the past week I could observe on the evenings of April 8th, 11th and 12th. Several objects were captured: the KH-12 USA 186 (05-042A) on all three evenings, IGS 1B (03-009B) on the 8th and 12th, the KH-12 USA 129 (96-072A) and the IGS 5r/b on the 8th. USA 186 slowly flared to -1 on the 11th at 20:34:45 UTC.

In addition, a number of strays were captured, including yet another Breeze-M tank (09-016C, from the Eutelsat W2A launch) and a non-classified military object, the DMSP B5D2-2 (83-113A) military weather satellite. The latter flared, with the flare peak near 20:34:12.87 UTC (secondary peaks near 20:34:12.45 and 20:34:13.37 UTC).

The DMSP flare was captured as a stray in a rather uniquely satellite-crowded image that also shows the KH-12 USA 186 (the target), the mentioned Breeze-M tank (09-016C), and a third stray, the Kosmos 1531 r/b (84-003B) all in an area of only a few degrees! Below is the image in question (the DMSP is moving from top to bottom here, USA from bottom to top):

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Below is the brightness profile of the DMSP flare derived from the image:

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During observations, I had a spectator: Pippi the cat followed my activities with close attention from behind the window:

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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:

click images to enlarge

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:

click image to enlarge

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).

click images to enlarge

GOCE keeps flaring

Yesterday evening (Jan 8) started clear. I captured GOCE (09-013A) flaring again, and then observed Lacrosse 3 (97-064A). I also tried the HEO objects USA 179 and 198 but due to a mistake in software parameters I keyed in, I photographed the wrong sky locations...

Next the sky got clouded again, the forerunners of snow.

The GOCE flare behaviour is by now getting familiar (if still in aspects unexplained: see the previous post). This time, the flare occurred at 17:02:55.1 UTC (Jan 8). This corresponds to an angle of 93.4 degrees and a tilt of 25.8 degrees.

Below is the picture and the resulting brightness diagram.

click images to enlarge

I also photographed a GOCE flare on 5 January, under appaling sky conditions. Start and end of the trail were not visible (hence, I cannot produce a brightnes sprofile for that flare) and in fact the flare even shos up only marginally (see image below). By measuring the brightest point of the flare and comparing to the GOCE orbit, it resulted in a flare time though: 17:15:48.1 UTC (Jan 5). This corresponds to an angle of 93.2 degrees and a tilt of 37.8 degrees.

click image to enlarge