Wednesday, 7 September 2011
I am giving Twitter a try - I know, I am late to jump on this bandwagon, but what with this observing blog and Facebook and all, it is already enough thin gs to update. Anyway, click on the small blue button with twitter logo in the top of the sidebar if you are interested in my tweets. They will not all be about satellites though, and some might occasionally be in Dutch.
SBSS 1
The attention to the hunt for USA 161 means I have a backlog of other objects to report. One of these is my first observation of SBSS 1 (2010-048A), the first object in the Space Based Space Surveillance (SBSS) series.
The picture above was made in the evening of September 1st, using the new Samyang 1.4/85mm lens. It shows SBSS 1 moving (left to right) through the northern part of Cygnus (bright star at left is Deneb).
SBSS 1 is the pathfinder mission in the SBSS series and was launched a year ago on 25 September 2010. It is too faint for my 2.5/50mm lens, but the 1.4/85mm Samyang captures it well and has a FOV that is wide enough to show the full trail.
The satellite consists of a 30cm telescope with a 2.4 megapixel sensor. It's purpose is to track other objects in space. A picture of it during assembly can be seen here.
click image to enlarge
The picture above was made in the evening of September 1st, using the new Samyang 1.4/85mm lens. It shows SBSS 1 moving (left to right) through the northern part of Cygnus (bright star at left is Deneb).
SBSS 1 is the pathfinder mission in the SBSS series and was launched a year ago on 25 September 2010. It is too faint for my 2.5/50mm lens, but the 1.4/85mm Samyang captures it well and has a FOV that is wide enough to show the full trail.
The satellite consists of a 30cm telescope with a 2.4 megapixel sensor. It's purpose is to track other objects in space. A picture of it during assembly can be seen here.
Above: mission and launch patches from the SBSS 1 launch
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.
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.
Friday, 2 September 2011
SPECTACULAR flare by IGS 1B!
Click images to enlarge! Do!
This picture speaks for itself. When this happened, I was jumping up and down in excitement, shouting "WOHOOOOO!!!!".
The picture shows the malfunctioned Japanese spy satellite IGS 1B flaring to at least magnitude -8 in Hercules (M13 can be seen as a fuzzy "star" in the picture) at 20:58:40 UTC (2 Sept 2011). It rivalled the best of Iridium flares.
Image shot with the Canon EOS 450D + EF 2.5/50mm Macro, 800 ISO. It was somewhat hazy with a few contrails in the sky, one of them lighting up around the flare for added drama.
Needless to say, I was extremely happy that this happened while the camera was open...
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:
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 forRed 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!
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
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.
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!
Wednesday, 31 August 2011
Rush hour on the Sagitta-Vulpecula border
Yesterday, while preparing the series of images on comet 2009 P1 Garrad (see previous post), I captured below 10 second exposure using the Samyang 1.4/85 mm lens. The telescope mount was not yet adequately following that time.
It shows satellite rush hour on the Sagitta-Vulpecula border: as much as four objects in this single image measuring less than 10 degrees!
11-037B is related to the SPEKTR R (Radioastron) launch. Kosmos 530 (72-087C) is clearly slowly flashing.
Later that evening, I captured the FIA Radar 1 (10-046A) passing through Cygnus amidst whisps of clouds, making for this eerie picture (made using the Canon EF 2.5/50mm Macro):
It shows satellite rush hour on the Sagitta-Vulpecula border: as much as four objects in this single image measuring less than 10 degrees!
11-037B is related to the SPEKTR R (Radioastron) launch. Kosmos 530 (72-087C) is clearly slowly flashing.
click image to enlarge
Later that evening, I captured the FIA Radar 1 (10-046A) passing through Cygnus amidst whisps of clouds, making for this eerie picture (made using the Canon EF 2.5/50mm Macro):
click image to enlarge
OT: comet 2009 P1 Garradd with the new 1.4/85 mm lens (updated)
Yesterday evening (30 Aug 2011) started reasonably clear, so I set up the small Meade ETX-70, put the Canon EOS 450D with the new Samyang 1.4/85 mm lens piggyback on it, and made a series of images of the Sagitta-Vulpecula border area, where comet 2009 P1 Garradd is currently located.
Sky conditions were variable. Out of 97 images (of 10 seconds exposure each), I selected the 34 best for the stack below. The comet (small, but with a clear tail) is in the center, parts of Sagitta with M71 are at left, the "coathanger" cluster is at right:
A detail of the image at full pixel resolution:
Sky conditions were variable. Out of 97 images (of 10 seconds exposure each), I selected the 34 best for the stack below. The comet (small, but with a clear tail) is in the center, parts of Sagitta with M71 are at left, the "coathanger" cluster is at right:
click image to enlarge
A detail of the image at full pixel resolution:
click image to enlarge
Tuesday, 30 August 2011
NOSS 2-1 (C) very bright
In the evening of August 28, during a short clearing, I was testing a new lens, the very fine Samyang F1.4/85 mm Aspherical IF.
The EOS 450D with the lens was mounted piggyback on my Meade ETX-70, with the ETX following the movement of the stars.
While making a series of images of the Deneb area, situated near the zenith, a bright naked eye satellite of mag. +1.5 passed through Cygnus and the camera field.
On the image, it turned out to be accompanied by two other satellites, much fainter. It actually was the NOSS 2-1 trio, and the bright one was the (C) component (1990-050C). Below is the image:
NOSS-es usually do not get this bright in the zenith and I have never seen 1990-050C this bright before. Scott Tilley from the USA has recently observed the same unusual brightness of NOSS 2-1(C), and so did Brad Young.
The lens I was testing, the Samyang F1.4/85 mm Aspherical IF which gets raving reviews on the internet, turns out to be an extremely fine F1.4 lens. The optical quality is astounding, and this at a cost of only €269,- !
The EOS 450D with the lens was mounted piggyback on my Meade ETX-70, with the ETX following the movement of the stars.
While making a series of images of the Deneb area, situated near the zenith, a bright naked eye satellite of mag. +1.5 passed through Cygnus and the camera field.
On the image, it turned out to be accompanied by two other satellites, much fainter. It actually was the NOSS 2-1 trio, and the bright one was the (C) component (1990-050C). Below is the image:
click image to enlarge
NOSS-es usually do not get this bright in the zenith and I have never seen 1990-050C this bright before. Scott Tilley from the USA has recently observed the same unusual brightness of NOSS 2-1(C), and so did Brad Young.
The lens I was testing, the Samyang F1.4/85 mm Aspherical IF which gets raving reviews on the internet, turns out to be an extremely fine F1.4 lens. The optical quality is astounding, and this at a cost of only €269,- !
Friday, 26 August 2011
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:
click image to enlarge
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:
click diagram to enlarge
Tuesday, 23 August 2011
Progress M-11M, and a spectacular flare by IGS 1B
At 9:35 UTC on 23rd August 2011, the Progress M-11M spacecraft (2011-027A) which had been attached to the International Space Station (ISS) since June was decoupled from the latter. It will orbit earth on its own for 9 days and will do various measurements, before being de-orbited to burn up over the Pacific.
On the evening of the 23rd near 20:29 UTC (22:29 local time) I watched them both during a fine near-zenith pass. The Progress spacecraft was about 1 minute ahead of the ISS in time, and attained a maximum brightness of mag. +0.5. Below two images show the Progress (top image) and the ISS a minute later(bottom image), both in Lyra:
Next I observed the IGS 5 rocket (09-066B), and IGS 1B (a malfunctioned Japanese spy satellite that is up for an uncontrolled re-entry in 2012-2013, see here). Both objects flared.
The IGS 5 rocket stage flared to mag. -0.5 at about 20:35:55 UTC. But IGS 1B (03-009B) flared much more spectacularly, to at least mag. -3 at 20:43:01 UTC, while passing through the zenith! An image of this splendid flare (captured close to the edge of the image) is the top image below, while the bottom image shows it while ascending in the south, just west of Altair:
On the evening of the 23rd near 20:29 UTC (22:29 local time) I watched them both during a fine near-zenith pass. The Progress spacecraft was about 1 minute ahead of the ISS in time, and attained a maximum brightness of mag. +0.5. Below two images show the Progress (top image) and the ISS a minute later(bottom image), both in Lyra:
click images to enlarge
Next I observed the IGS 5 rocket (09-066B), and IGS 1B (a malfunctioned Japanese spy satellite that is up for an uncontrolled re-entry in 2012-2013, see here). Both objects flared.
The IGS 5 rocket stage flared to mag. -0.5 at about 20:35:55 UTC. But IGS 1B (03-009B) flared much more spectacularly, to at least mag. -3 at 20:43:01 UTC, while passing through the zenith! An image of this splendid flare (captured close to the edge of the image) is the top image below, while the bottom image shows it while ascending in the south, just west of Altair:
click images to enlarge
Sunday, 21 August 2011
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.
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).
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.
click images to enlarge
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).
click image to enlarge
Thursday, 18 August 2011
Nanosail-D: a pattern in the Chaos
Earlier I reported on my August 14 observations of the experimental Solar sail Nanosail-D (2010-062L), including a brightness variation diagram derived from one of the images.
Initially, I could not see any clear pattern in it, so I called it "irregular". Next, Alain Figer from France pointed out it was not so irregular after all. His own images from August 16th (URL's here) show a very neat pattern of one major flash, then two secondary flashes, then a major flash again. On his images, the major flashes are 0.73 seconds apart.
Going back to my observations, it turns out it is indeed possible to find a similar periodicity of 0.73 +/- 0.03 seconds. The secondary flashes appear to be 0.73/3 = ~0.24 from these main peaks: in other words, main and secondary peaks fit a ~0.24s pattern.
Below diagram shows it. the lowest line gives the observed peaks, with the red triangles representing the main 0.73s cycle. The yellow tringles point out several secondary maxima at ~0.24s after the main cycle peak; the grey/white triangles point at a hint of a similar pattern ~0.24s before he main cycle peaks.
The upper line shows the modelled behaviour: a main peak (black triangle) each 0.73s, with secondary and tertiary peaks at ~0.24s intervals.
Initially, I could not see any clear pattern in it, so I called it "irregular". Next, Alain Figer from France pointed out it was not so irregular after all. His own images from August 16th (URL's here) show a very neat pattern of one major flash, then two secondary flashes, then a major flash again. On his images, the major flashes are 0.73 seconds apart.
Going back to my observations, it turns out it is indeed possible to find a similar periodicity of 0.73 +/- 0.03 seconds. The secondary flashes appear to be 0.73/3 = ~0.24 from these main peaks: in other words, main and secondary peaks fit a ~0.24s pattern.
Below diagram shows it. the lowest line gives the observed peaks, with the red triangles representing the main 0.73s cycle. The yellow tringles point out several secondary maxima at ~0.24s after the main cycle peak; the grey/white triangles point at a hint of a similar pattern ~0.24s before he main cycle peaks.
The upper line shows the modelled behaviour: a main peak (black triangle) each 0.73s, with secondary and tertiary peaks at ~0.24s intervals.
click diagram to enlarge
Monday, 15 August 2011
Nanosail-D flashing rapidly and brightly
As in late May and early June, Nanosail-D (2010-062L), the experimental NASA Solar Sail is making favourable passes again and under favourable conditions becomes bright and is flashing rapidly.
Yesterday evening around 22:50 local time (20:50 UTC) I observed it when it made a near-zenith pass, from SW to NE. While ascending and going through the zenith it was quite bright and an easy naked-eye object, reaching mag. +1.5. It was rapidly and very irregularly, rather nervously flashing.
I shot four images, two of which are shown below: in the first image, the brightness variation is photographically less apparent than it was visually, because the trail is near saturation. It shows the Solar sail passing just below Lyra (Vega in top left) along with a stray, the French Optical Remote Sensing satellite Spot 4 (98-017A, the fainter of the two trails).
The second image, shot while Nanosail-D was getting fainter, shows the sharp flashes more readily.
From the latter image, I could derive this brightness variation diagram:
A large number of sharp brightness peaks can be seen: I count some 26 peaks in a 10.05 seconds time span, the one more prominent than the other. No regularity in the pattern is apparent.
Yesterday evening around 22:50 local time (20:50 UTC) I observed it when it made a near-zenith pass, from SW to NE. While ascending and going through the zenith it was quite bright and an easy naked-eye object, reaching mag. +1.5. It was rapidly and very irregularly, rather nervously flashing.
I shot four images, two of which are shown below: in the first image, the brightness variation is photographically less apparent than it was visually, because the trail is near saturation. It shows the Solar sail passing just below Lyra (Vega in top left) along with a stray, the French Optical Remote Sensing satellite Spot 4 (98-017A, the fainter of the two trails).
The second image, shot while Nanosail-D was getting fainter, shows the sharp flashes more readily.
click images to enlarge
From the latter image, I could derive this brightness variation diagram:
click diagram to enlarge
A large number of sharp brightness peaks can be seen: I count some 26 peaks in a 10.05 seconds time span, the one more prominent than the other. No regularity in the pattern is apparent.
Wednesday, 10 August 2011
Perseid
Yesterday evening saw very dynamic weather conditions, with the sky going from overcast to cklear to overcast in a matter of minutes. I managed to photograph the FIA Radar 1 (10-046A) and IGS 1B (03-009B).
Then I set up my camera with an Aputure automatic timer and let it take 20 second pictures all night. I did this earlier, to construct a time-lapse showing sky rotation. This time, it was also meant to capture some early Perseid meteors.
I captured one (below), low in the west.
Then I set up my camera with an Aputure automatic timer and let it take 20 second pictures all night. I did this earlier, to construct a time-lapse showing sky rotation. This time, it was also meant to capture some early Perseid meteors.
I captured one (below), low in the west.
click image to enlarge
Friday, 15 July 2011
Some of my pictures on Wired.com
Wired.com has published a short photographic item about secret spacecraft today.
Two of the images in it were shot by me: a photograph of Lacrosse 3 and one of Mentor 4.
Two of the images in it were shot by me: a photograph of Lacrosse 3 and one of Mentor 4.
Tuesday, 12 July 2011
Prowler
Among the family of classified satellites, three stand out as more mystifying than the rest: Misty 1 & 2, PAN, and Prowler.
The latter has long existed in the realm of rumours only. It was launched by Space Shuttle Atlantis on mission STS-38, which was a classified DoD mission launched on 15 November 1990. Officialy only one satellite, USA 67, was launched from the Atlantis payload bay. This is believed to be a geostationary SDS communications satellite, SDS 2-2.
USSTRATCOM released catalogue numbers (but no public orbit) for three objects connected to this launch: the SDS satellite USA 67 itself (90-097B, 20963) plus two rocket bodies (90-097 C & D, 20964 and 20965).
The latter was puzzling, as it is one too many (see the discussion by Ted Molcan here), This was the start of the idea that a second, unacknowledged object was launched by STS-38 as well.
In 2004 an NBC journalist referred to such a secret payload by the name of Prowler, in a news-item discussing a Senate debate about a classified spy satellite program drawing criticism for massive cost overruns. The same journalist, citing anonymous sources, did so again in 2007.
According to these stories, Prowler was an experimental satellite used for close inspection of other (non-US) satellites in geostationary orbit (see discussion here), reportedly coming to within decimeters of some satellites. There are suggestions that it was a test of technology which, in wartime, could be used to sabotage enemies' space assets. It was also said to employ stealth technologies to evade easy detection.
Meanwhile, US amateur observers Ed Cannon and Mike McCants had discovered an unidentified near-geostationary object in July 1998. As time progressed and more and more ISON and amateur-discovered objects could be identified with specific launches, this one was one of few left unidentified. This in turn led to suggestions that the object in question was the rumoured unacknowledged STS-38 launch, Prowler. It was likely discovered only after its active lifetime ended, and it was put in a disposal orbit (see below).
Since then, a long term analysis by Ted Molczan has strengthened this identification. The object has al the right characteristics in terms of brightness behaviour and orbital behaviour. It currently is in an unusual librating disposal orbit that seems devised to keep it out of reach of Soviet tracking facilities (see discussion in depth by Ted here). In a second analysis, Ted showed that STS-38 indeed had the opportunity to launch this object and some tell-tale clues to that are present in the manoeuvering history of STS-38 Atlantis. The whole history of the object, from launch onwards but also including the final disposal orbit when the stealth character of the object was lost, was designed with low detectability by Soviet tracking facilities in mind (see Ted's discussion here).
The object now resides in a currently 13-degrees inclined orbit librating between 73 W and 136 W, putting it over the eastern Pacific, with visibility from the western United States. Over the past two weeks , I imaged it a number of times, using the 0.61-meter "remote" telescope of Sierra Stars observatory in California. Below is one of the better images, shot on the morning of July 6th:
The latter has long existed in the realm of rumours only. It was launched by Space Shuttle Atlantis on mission STS-38, which was a classified DoD mission launched on 15 November 1990. Officialy only one satellite, USA 67, was launched from the Atlantis payload bay. This is believed to be a geostationary SDS communications satellite, SDS 2-2.
STS-38 mission patch
USSTRATCOM released catalogue numbers (but no public orbit) for three objects connected to this launch: the SDS satellite USA 67 itself (90-097B, 20963) plus two rocket bodies (90-097 C & D, 20964 and 20965).
The latter was puzzling, as it is one too many (see the discussion by Ted Molcan here), This was the start of the idea that a second, unacknowledged object was launched by STS-38 as well.
In 2004 an NBC journalist referred to such a secret payload by the name of Prowler, in a news-item discussing a Senate debate about a classified spy satellite program drawing criticism for massive cost overruns. The same journalist, citing anonymous sources, did so again in 2007.
According to these stories, Prowler was an experimental satellite used for close inspection of other (non-US) satellites in geostationary orbit (see discussion here), reportedly coming to within decimeters of some satellites. There are suggestions that it was a test of technology which, in wartime, could be used to sabotage enemies' space assets. It was also said to employ stealth technologies to evade easy detection.
Meanwhile, US amateur observers Ed Cannon and Mike McCants had discovered an unidentified near-geostationary object in July 1998. As time progressed and more and more ISON and amateur-discovered objects could be identified with specific launches, this one was one of few left unidentified. This in turn led to suggestions that the object in question was the rumoured unacknowledged STS-38 launch, Prowler. It was likely discovered only after its active lifetime ended, and it was put in a disposal orbit (see below).
Since then, a long term analysis by Ted Molczan has strengthened this identification. The object has al the right characteristics in terms of brightness behaviour and orbital behaviour. It currently is in an unusual librating disposal orbit that seems devised to keep it out of reach of Soviet tracking facilities (see discussion in depth by Ted here). In a second analysis, Ted showed that STS-38 indeed had the opportunity to launch this object and some tell-tale clues to that are present in the manoeuvering history of STS-38 Atlantis. The whole history of the object, from launch onwards but also including the final disposal orbit when the stealth character of the object was lost, was designed with low detectability by Soviet tracking facilities in mind (see Ted's discussion here).
The object now resides in a currently 13-degrees inclined orbit librating between 73 W and 136 W, putting it over the eastern Pacific, with visibility from the western United States. Over the past two weeks , I imaged it a number of times, using the 0.61-meter "remote" telescope of Sierra Stars observatory in California. Below is one of the better images, shot on the morning of July 6th:
click image to enlarge
Wednesday, 6 July 2011
An update on IGS-1B
Along the line of expectations, our tracking data show that the Japanese spy satellite IGS 1B (2003-009B) which malfunctioned in March 2007, keeps coming down (see earlier coverage here and here).
Early July 2011, the perigee had come down to 450 km and the Mean Motion (the number of orbital revolutions per day) is steadfastily increasing as the orbit becames more narrow:
The predicted decay date keeps shifting back and forth, being highly dependant on solar activity. Solar activity has been back to modest the past two months. As a result, the decay date forecast has shifted further away in time.
If solar activity does not increase, forecasted decay will be in late 2013 (SatEvo with current solar flux F10.7 cm = 85, elset 11184.15154535). If it does increase - which is likely, as we are on the approach to a solar maximum - it will be earlier, possibly as early as mid-2012.
Meanwhile, it is interesting to see how the still active sister-ship IGS 1A (2003-009A), launched in the same 2003 launch, is faring. Above diagram shows the evolution of the orbital inclination. IGS 1B's orbital inclination is clearly drifting, consistent with loss of control. IGS 1A's orbital inclination initially was allowed to co-drift with IGS 1B, but then altered in a manoeuvre mid-2008 that brought the inclination up again, to match the other IGS-es in the constellation. As of 2010, it is kept more or less steady, librating around a value of 97.39 degrees, the sun-synchronous value for a 487 x 498 km orbit.
Early July 2011, the perigee had come down to 450 km and the Mean Motion (the number of orbital revolutions per day) is steadfastily increasing as the orbit becames more narrow:
The predicted decay date keeps shifting back and forth, being highly dependant on solar activity. Solar activity has been back to modest the past two months. As a result, the decay date forecast has shifted further away in time.
If solar activity does not increase, forecasted decay will be in late 2013 (SatEvo with current solar flux F10.7 cm = 85, elset 11184.15154535). If it does increase - which is likely, as we are on the approach to a solar maximum - it will be earlier, possibly as early as mid-2012.
Meanwhile, it is interesting to see how the still active sister-ship IGS 1A (2003-009A), launched in the same 2003 launch, is faring. Above diagram shows the evolution of the orbital inclination. IGS 1B's orbital inclination is clearly drifting, consistent with loss of control. IGS 1A's orbital inclination initially was allowed to co-drift with IGS 1B, but then altered in a manoeuvre mid-2008 that brought the inclination up again, to match the other IGS-es in the constellation. As of 2010, it is kept more or less steady, librating around a value of 97.39 degrees, the sun-synchronous value for a 487 x 498 km orbit.
PAN, and the NOSS 3-5 duo
Monday evening was a nice clear evening with a very transparent sky.
I observed the NOSS 3-5 duo (11-014 A & B), which was captured in a very fine image with a stray nearby, the rocket from the Kosmos 1697 launch (85-097B). De double parallel trail above is the NOSS duo, the single trail under an angle is the Russian rocket (bright star near trails is Deneb):
I also took opportunity of the transparent sky to target some geostationary objects low in the southeast. Targets were PAN (09-047A) and Mentor 4 (09-001A):
I observed the NOSS 3-5 duo (11-014 A & B), which was captured in a very fine image with a stray nearby, the rocket from the Kosmos 1697 launch (85-097B). De double parallel trail above is the NOSS duo, the single trail under an angle is the Russian rocket (bright star near trails is Deneb):
click image to enlarge
I also took opportunity of the transparent sky to target some geostationary objects low in the southeast. Targets were PAN (09-047A) and Mentor 4 (09-001A):
click image to enlarge
Monday, 4 July 2011
Imaging geostationary satellites using a remote telescope [UPDATED]
I have been using the "remote" telescopes of Sierra Stars observatory in California and Winer Observatory in Nevada for some time now to image asteroids (recently, earthgrazing NEA 2011 MD).
The past two days I have used the Sierra Stars Obs. 0.61-meter Cassegrain telescope to make some "remote" images of classified geostationary satellites that are not visible from the Netherlands, but visible from the western United States. It concerned the recently launched SBIRS-GEO1 satellite (11-019A) and the mysterious object (90-097E) that is most likely Prowler, launched in 1990 on STS-38.
Below are the images: as this is a guided telescope, the satellites have created trails on the images. Top image: Prowler. Bottom image: SBIRS-GEO1, plus an unidentified object (UPDATE: the latter object might be the SBIRS-GEO r/b).
The past two days I have used the Sierra Stars Obs. 0.61-meter Cassegrain telescope to make some "remote" images of classified geostationary satellites that are not visible from the Netherlands, but visible from the western United States. It concerned the recently launched SBIRS-GEO1 satellite (11-019A) and the mysterious object (90-097E) that is most likely Prowler, launched in 1990 on STS-38.
Below are the images: as this is a guided telescope, the satellites have created trails on the images. Top image: Prowler. Bottom image: SBIRS-GEO1, plus an unidentified object (UPDATE: the latter object might be the SBIRS-GEO r/b).
click images to enlarge
Tuesday, 28 June 2011
OT: more imagery of the earthgrazing asteroid 2011 MD
Like yesterday, I used the 0.61-meter F/10 Cassegrain of Sierra Stars Observatory (G68) in California again to image the earthgrazing asteroid 2011 MD, this time a few hours after closest approach.
Below animated GIF was made from three 30 second exposures, spaced 30 seconds, starting at 09:35:01 UTC (28 June).
Below animated GIF was made from three 30 second exposures, spaced 30 seconds, starting at 09:35:01 UTC (28 June).
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