Prowler captured flaring again

On June 10 of last year (2014) I captured a brief bright flare of Prowler (1990-097E) when imaging it 'remote' with the 0.61-m Schmidt-Cassegrain of MPC G68 Sierra Stars Observatory in California, USA.

Last week on March 7, Prowler again briefly flared while I was imaging it with the same telescope, Note the brightening of the trail near the left end of it:

It is a flare of the same short specular type as that of last year. It was captured in one of three brief 30-second exposure  images taken near 03:45UT: the flare is close to the end of the trail in the second image, i.e. occuring at about 03:45:10 UT (March 7, 2015). Here is a stack of all three images:

These brief specular flares are superimposed on what seems to be another, very slow periodicity in brightness.

Prowler itself is a very interesting, enigmatic object. It was a clandestine launch from Space Shuttle STS-38 in 1990 and long existed in the realm of rumours only. It was a top secret experimental  satellite with stealth characteristics, meant to make close inspections of third party satellites in GEO orbit. I have written an extensive in-depth post on the story of Prowler before which you can read here.

Prowler flaring

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I have written on the enigmatic Prowler satellite (1990-097E) before. I periodically observe it using a 'remote' telescope (usually the 0.61-meter Cassegrain of SSON, MPC G68).

On 2014 June 10 I captured it briefly flaring - I had not observed that before, though other observers had. The brief flare can be seen near the edge of the image (the trail runs out of the FOV) in the lowermost of the two images above.

Approximate positions of this flare:

- begin RA 17 25 24.73 DEC -20 49 41.7
- maximum RA 17 25 26.15 DEC -20 49 45.2
- end RA 17 25 27.36 DEC -20 49 45.6

Extrapolation from the measured timed positions above, gives the following approximate times for the flare:

- begin 09:25:23.9 (UT, 10 June)
- maximum 09:25:25.3 (UT, 10 June)
- end 09:25:26.5 (UT, 10 June)

Apart from these short flashes, observers report a much slower brightness variation. Indeed, I had suspected such from my own observations, as the trail brightness widely varies (between bright and completely invisible) between different image sessions. On May 27 for example, I also tried to image Prowler using the same 0.61-meter telescope, but it was invisible.

As Allen Thomson remarked, part of this brightness behaviour might be due to Prowler's former stealth characteristics.

An unknown object in (near) Geostationary orbit: Express AM-5?

The evening of December 29 2013 started clear, so I did a small survey of a part of the geostationary belt. Main focus of the session was PAN, as well as Mentor 4 and 6.

Inspecting the images I found an unidentified object in near-Geostationary orbit some 4 degrees east of PAN, between Mentor 6 and NSS 5, on several images (positions here). The image below shows it near M42, the Orion nebula, near 19:17 UT:

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In addition to the UNID you can also see a classified satellite at left, Mentor 6 (2012-034A), a SIGINT satellite also known under the code name Advanced Orion. At right are two commercial geostationary satellites, NSS 5 (1997-053A) and Galaxy 26 (1999-005A).

Cees Bassa in the Netherlands and Greg Roberts in South Africa also observed what is likely the same UNID object later that night. While it is not easy to fit a reliable orbit to such a relatively short span of observations, the suggestion is an object with an inclination near 0 and a Mean Motion of about 0.92 revolutions per day, i.e. an object near Geostationary altitudes.

The Mean Motion could suggest an old object being moved to a Graveyard Orbit. If this is the case, we haven't been able to identify which 'old' object it is yet.

Another option is that this is a new object. The only likely candidate in that case is the Russian satellite Express AM-5 which was launched on December 26th. This object seems to have been temporarily "lost" by JSpOC: as I write this (Jan 2),  Space-Track does not list orbital elements later than December 26th (when it was still in  a temporary transfer orbit).

For the moment, Mike McCants has given it the name UNK 131229 (with the acronym UNK meaning "Unknown").

This observing session also served to check on PAN (2009-047A). PAN is a highly mobile satellite and often moves position in May and December (I have written on the mystery of this satellite before). Not this time, it seems: it is still at the position it has been in for several months, forming a trio with the commercial satellites Yahsat 1B and Intelsat 10:

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Other classified objects imaged this night were the old SIGINT Mercury 1 (USA 105, "Advanced Vortex", 1994-054A), and the SIGINT Mentor 4 (USA 202, 2009-001A). Mercury 1 was placed at 48 E and recovered by me about a year ago.

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During this observing session, I captured a bright irregular orange light moving across the sky: a 'Thai Lantern' ( a miniature hot-air balloon). They are the cause of many false fireball and re-entry reports. Here it is, moving through Orion while carried by the wind:

Two days earlier, on December 27, I also did my periodic check on Prowler (90-097E), using the 61-cm Cassegrain of Sierra Stars Observatory in Markleeville, California (MPC G68).

I concluded the evening of the 29th by making some shots of M31, the Andromeda Galaxy. Unfortunately, some thin haze came in after a while. The image below is a stack of 16 haze-free images of 30 seconds exposure each, with a CLS filter (against light pollution - the images were taken from Leiden town center)) and Zeiss 2.8/180mm lens piggyback on the mount of my C6:

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Tracking Prowler

Last week I imaged Prowler again, the classified spacecraft we amateur trackers indicate with the informal Cospar code 2009-097E. The object (no longer operational) is in a librating geosynchronous disposal orbit located over the eastern Pacific. It is hence not visible from the Netherlands. I therefore use a 'remote' telescope in the US to observe it.

Prowler is (or was) one of the most secret and enigmatic objects in existence. It was probably an experimental satellite for close covert inspection of Soviet geostationary satellites. I have posted on the background story of this object in more detail before. Clandestinely launched from Space Shuttle STS-38 in 1990, its launch and existence have never been acknowledged by the US government.

The images below were made on October 25 and 27, using the 61-cm F/10 Cassegrain of Sierra Stars Observatory in Markleebergville, California.

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Both images have an exposure time of 30 seconds. The brightness difference between the two images is mostly due to a difference in phase angle.

30 (mostly) geostationary objects in one image

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The image above was made by me just after midnight of June 18-19, 2012. It is a single image taken with my new Canon EOS 60D and a SamYang 1.4/85mm lens (800 ISO, 10s exposure). It was shot from the center of Leiden town.

The image shows a 11 x 14 degrees wide field low in the south-southeastern sky, between 20 and 30 degrees elevation above the horizon. Diagonally over the image runs a part of the geostationary belt, at declination -7.4 deg for my location.

In this single image, as much as 30 mostly geostationary satellites are visible: 23 commercial geostationary satellites, 1 classified military geostationary satellite (Milstar 5, 2002-001A), and 6 rocket boosters.

I did a poor job with the focus of this image, resulting in a slight unsharpness (especially near the edges of the image). Yet, the number of  objects nevertheless visible in this small piece of low southern sky is amazing!

This is just one of several images I took that night. Apart from Milstar 5, a number of other classified (military) geostationary satellites were imaged and astrometry on them obtained.



PAN in it's new position at 37.9 E

One of these objects is PAN (2009-047A), an enigmatic satellite I have written about before. Here is an image from June 18-19:

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One of the curious aspects of this strange classified geostationary satellite operated by an undisclosed agency (see Dwayne Day's article in The Space Review), is that it is very frequently repositioned. It recently did so again (see my imagery of May 16, when it was still on the move). It has now stopped drifting and taken up position at 37.9 deg E (a position it has occupied before) not far from Paksat 1R, as can be seen in the image above. A stray Atlas Centaur rocket booster passed the area as well when the image was taken.


Vortex 4 and Mercury 2

Other classified objects imaged include  the older geostationary satellites Vortex 4 (1984-009A) and Mercury 2 (96-026A), the latter of which currently also is on the move (it is probably being sent to a disposal orbit after reaching the end of its operational mission):

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Vortex 4  (launched on 31 January 1984) and Mercury 2 (USA 118, launched on 24 April 1996) both are SIGINT (eaves-dropping) satellites, with the Mercury being a further advanced version of the Vortex.

In addition, a newer SIGINT satellite was imaged as well,  Mentor 4 (2009-001A, one that frequently features in this observational blog, as it is bright and easy to observe), and the object designated by our amateur network as  UNK 060616 (probably an old r/b).


Prowler, AEHF 1 and DSP F15 imaged from Winer observatory, USA

While the above imaging was all done from my home in the Netherlands, I also imaged a few objects 'remotely' using the UoI Rigel (MPC 857) 37-cm Cassegrain telescope at Winer Observatory, Sonoita, Arizona, USA.

The enigmatic Prowler (1990-097E), a clandestine launch from Space Shuttle mission STS-38 which has featured on this blog more often (read the intriguing story of Prowler here; plenty of suspense!) was imaged on June 19 and 22. On June 19 I also imaged the military communications satellite AEHF 1 (2010-039A), and on June 22 the old DSP Infra-red early-warning satellite DSP F15 (1990-095A). Images of these objects below:

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Comet 185P/Petriew

In addition to all these satellites, two  Solar System Minor Bodies were imaged: 2012 LZ1 and 185P/Petriew.

I posted imagery of the June 15 fly-by of Near Earth Asteroid (NEA) 2012 LZ1 here before in my previous post, and obtained more astrometry on this object on subsequent nights. In addition, I obtained some imagery on the faint periodic comet 185P/ Petriew on June 22. Below is a stack of 5 images of 45s exposure each:

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Not a pretty picture, but the comet was near magnitude +17 to +18! My astrometry has been included in MPEC 2012-M33 (22 June).


New camera: a Canon EOS 60D

I had completely forgotten to mention this: during the second half of May, my EOS 450D camera broke down. During a macro-session on Dragonflies, the shutter broke. Much to my regret.

I had the choice between having the shutter repaired (expensive), or buying a new camera. I choose the latter option, as the new generation of EOS cameras performs notably better than the 450D, especially in performance at high ISO (less noise). So I decided to upgrade.

The choice I made was for the Canon EOS 60D, an 18 MP DSLR with Digic IV processor. So far (and having mostly used it for "normal" photography for now) I very much like it!

Before I can use it on satellites in Low Earth Orbit, I'll first have to complete a calibration program with the camera. This calibration entails the delay between the moment you press the shutter button and the exposure is actually taken; and the real duration of exposures (a "10 second" exposure is not exactly 10.00 seconds). I have some preliminary calibration results by now, but it will take some time before I have final results and can start to use the camera regularly on satellites. For geostationary satellites (where the timing accuracy isn't that much of a factor; rather the astrometry is) the preliminary results I have mean I can already use it (as has been done, see this post).

IGS 1B on 12 and 13 May

After a month of generally bad weather conditions, two clear evenings allowed to track IGS 1B (2003-009B) again, the malfunctioned Japanese spy satellite that will have an uncontrolled reentry this summer.

Below video shows footage from both evenings: it opens with May 12 footage of IGS 1B crossing through Bootes and Corona Borealis (25 mm lens), and next shows footage of May 13 showing it moving through Leo and Uma (9 mm wide angle lens)




The photograph below was shot in the evening of May 13 using the EF 2.0/35mm lens, showing IGS in Leo over the roof of my house:

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Other objects tracked include the IGS 5 r/b (09-066B). I also obtained remote telescopic imagery of Prowler (90-097E) using the 37-cm Rigel telescope in Sonoita, Arizona.

MiTEx 1, AEHF 1 and Prowler

Weather conditions have not been too well lately. In the evening of March 14, I could do some imaging from Leiden, albeit under hazy skies. The relatively bright geostationary SIGINT Mentor 2 (98-029A) was the target.

In addition, I used a "remote" telescope, the 37-cm F14 Rigel Cassegrain of Winer Observatory (MPC 587) to image a few geostationary objects over US longitudes. Targets were (below images from top to bottom) the communication satellite AEHF 1 (10-039A), and the enigmatic objects MiTEx 1 (06-024A) and Prowler (90-097A).

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AEHF 1 (aka USA 214) is the first of the Advanced Extremely High Frequency communication satellites that should replace the Milstar system. Because one of its onboard rocket boosters failed, the satellite had to be brought from GTO to its geostationary destination using smaller thrusters designed for station keeping, a procedure which took over a year.

This was the first time I imaged AEHF 1.

Prowler and MiTEx 1 are both enigmatic objects. Prowler's unique story has been discussed here before. MiTEx 1 (USA 187)  is an enigmatic object that has some connection to the Prowler legacy. Like Prowler presumably was, it was designed to inspect other satellites. Two MiTEx satellites were launched (in the same launch in 2006), MiTEx 1 and 2. They were used to inspect, amongst others, the failed DSP satellite DSP-23 in 2009. I imaged MiTEx 2 before, this was the first time I also imaged MiTEx 1.

ISS, Prowler, and a flashing Vortex 1 rocket

Apart from a  glimpse through clouds of the ISS on January 2nd (video posted here earlier), I managed to do my first observations of 2012 this weekend, in the evening of January 7 from Leiden and (using a remote telescope in the USA) on January 9.

Conditions were not ideal on January 7th: a lot of moonlight and intermittent clouds. I observed the HEO object USA 200 (08-010A), but due to the moonlight interference the trails were weak (but good enough to get a few positions) and the pictures not pretty.

For the night of January 8-9, I scheduled a few observations on a "remote" telescope, the 61-cm F10 Cassegrain of SSON in California. Target was Prowler (90-097E), an enigmatic object discussed here earlier.

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The image series on Prowler (I always take a series of at least three images at minute intervals, in case the object is a bit off from predictions) contained a flashing stray.

This turned out to be a classified object as well: Vortex 1r, the r/b from the Vortex 1 launch (78-058B). This rocket stage is clearly tumbling or spinning, as attested by a quite regular flash pattern:

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The main flashes are 2.96 seconds apart, and flanked on each side by slow secondary flashes about 0.47s before and after the sharp main flashes, giving the trail on the image a dash-dotted appearance.

Observing Geostationary Satellites from Leiden and Arizona

While the focus was on LEO and HEO satellites earlier in October, I primarily targetted Geostationary satellites last week. Both from my own locality with my own equipment, as well as by means of a "remote" telescope in Arizona.

The two images below were taken from Leiden (the Netherlands) in the early evening of October 23, using my own equipment (Canon EOS 450D + Carl Zeiss Jena Sonnar MC 2.8/180mm).

They show the enigmatic, frequently re-locating PAN satellite (09-047A: see Dwayne Day's article here) and the SIGINT (eavesdropping) Mentor 4 (USA 202) satellite (09-001A), as well as a few commercial geostationary telecom objects: Hellas-sat 2 (03-020A), Thuraya 2 (03-026A) and Paksat 1R (11-042A).

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As can be seen, PAN and Hellas-sat 2 are a very close pair now, so close that I am not actually 100% sure which one is which (the westernmost one or rightmost one is likely PAN). As can be seen in comparison to this post from May, it has relocated again, from 45.0 to 38.9 E - it did so in July, when I was on hollidays.

Somewhat earlier the same week, when the sky in Leiden was overcast, I took refuge by hiring a "remote" telescope again. This time not the 61-cm of SSON, but the 37-cm Cassegrain of Winer Observatory (MPC 857) in Sonoita, Arizona, USA. While a smaller instrument, this telescope has a larger FOV which is good if the satellite is a bit off from predictions, and allows te satellite to be captured on more than one image when a 3-image run is done. Also, it is cheaper to rent.

Targets were two "usual suspects": the enigmatic Prowler (90-097E: see story and links in my previous post here) on October 17 and 21 and the SBIRS-GEO 1 (11-019A) on October 21:

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Note: because the telescope follows the stars, the satellites become trailed, unlike the images shot from Leiden which are from a stationary tripod (hence the stars trail, but the satellites not).

A few non-geostationary satellites were tracked the past two weeks as well. They include the STSS Demo 1 & 2 (09-052 A & B) and the USA 89 r/b (92-086C) on October 22, and the HEO ELINT & SBIRS platform USA 184 (06-027A) on October 15.

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.

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:

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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).

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