The re-entry of IGS 1B on 26 July 2012

While I was away on holidays, the Japanese spy satellite IGS 1B (03-009B) that malfunctioned in March 2007, re-entered on 26 July 2012, over Polynesia.

The demise of this satellite was covered for over a year on this blog: as the satellite was weighing 1.2 tons and as it had an unknown amount of remnant fuel onboard, the uncontrolled reentry raised some questions and initial concerns (see coverage here).

The last amateur observations of the object were done by Mike Waterman (USA) on July 24th and Alain Figer (France) in evening twilight of July 25th. The last amateur orbital update by Ted Molczan based on a.o. Mike Waterman's observations, showed it to have descended to a 211 x 213 km orbit on July 24th and analysis of this dataset by this author using Alan Pickup's SatEvo suggests reentry on July 26, somewhere between approximately 9:50 and 10:50 UTC.

USSTRATCOM published a final TIP for IGS 1B on July 26th (that they did so for a classified object is unusual), placing re-entry at 26 July 2012, 09:52 +/- 2 min UTC, near 25 S, 186 E, which is near New Zealand. This is at the start of the reentry window given above and hence seems very reasonable even though the reentry coordinates are a verbatim copy (down to one decimal) of a pre-decay prediction issued at 7:34 UTC (only the uncertainty value has changed, from 2 hours to 2 minutes). No details on the orbital development in the final few revolutions were given.

The map below shows the USSTRATCOM determined reentry location and final trajectory. In principle, the re-entry could have been observed from the northern islands of New Zealand and potentially the Fiji-Tonga area. Note that only half a revolution later (about 30 minutes later) it would have passed over NW Europe and next west Africa.

click map to enlarge

The diagram below shows the orbital evolution in terms of apogee and perigee altitudes, from malfunction early 2007 to decay on 26 July 2012. It is based on orbital element sets calculated by Mike McCants and Ted Molczan from amateur observations, including mine:

click diagram to enlarge

2

IGS 1B was a nice object to observe over the past years: it was bright, and it was interesting to follow its orbital evolution towards decay. The observation that remains the most vivid imprint in my memory is the one that resulted in the picture below: on 2 September 2011, while I was watching and photographing a pass in a slightly hazy sky, the satellite brightly flared to at least magnitude -8 if not more: the brightest satellite flare I have ever seen. I was jumping up and down and yelling "WOOOOOWWWW!!!!" when this happened. It resulted in this wonderful, eerie picture:

click image to enlarge

Update on IGS 1B (10 June 2012)

We are slowly getting closer to the uncontrolled re-entry of the 1.2 tons malfunctioned Japanese spy satellite IGS 1B (2003-009B). The satellite's orbit has by now dropped below 340 km altitude (see second diagram below, perigee/apogee values from orbits calculated by Mike McCants based on amateur observations including mine). That is well below the ISS orbital altitude (ISS is currently in a 392 x 406 km altitude orbit). A mere month ago it was still considerably higher, in a 366 x 368 km orbit: it lost over 25 km or orbital altitude since. It is dropping fast, and the rate increases (see diagram below).

Using the latest amateur orbital elements for the object and Alan Pickup's SatEvo software with the current 10.7 cm solar flux, re-entry is currently estimated to occur between mid-July and early August 2012.

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:

click image to enlarge

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.

An update on IGS 1B - a spy satellite about to reenter this summer

(updated reentry prediction at the end of this post)

Last year I wrote extensively about the malfunctioned Japanese spy satellite IGS 1B (2003-009B) which is about to reenter, uncontrolled, into the atmosphere soon. The above footage of the object was shot by me last April 13 and 14 and shows two passes over Leiden.

This radar satellite, launched to keep an eye on North-Korea in 2003, malfunctioned in March 2007, halfway though its mission. Since then, it has been steadily coming down (see diagrams below) in a way that clearly shows that the satellite operators do no longer have control over it.

Last year, I pointed to the fact that the 1.2 tons  satellite will reenter in 2012 (so this year), and likely still has some remnant fuel onboard. A subsequent assessment by high-end amateur satellite tracker Ted Molczan showed that this amount of fuel is limited - probably about 14 to 50 kg, an order of a magnitude less than the infamous case of USA 193 in 2008. This assessment is important, as an uncontrolled reentry of a satellite with fuel onboard is a potential hazard (reason why I wrote about it last year) and authorities were (and are) very quiet about it. Ted's assessment, the only public one to date, helped to put the potential risks involved into proper context.

In the autumn of 2011 we temporarily lost track of IGS 1B because it entered winter invisibility for the Northern hemisphere (where most of our observers are located). Early April this year, it emerged from this winter blackout again. I did a failed attempt to recover it on the evening of April 2, and then Russell Eberst successfully recovered it a day later on the evening of April 3. Since then, I observed it on April 13, 14 and 22 (see video footage above of the April 13 and 14 passes) and other amateurs have observed it as well.

Below is a 35-second integration of video frames from the April 13 video (upper right are tail stars of the Big Dipper):

click image to enlarge

Orbital evolution over the winter blackout

When IGS 1B was lost in the winter blackout in the autumn of 2011, it was in a 453 x 455 km orbit. Since then, it has come down considerably: as of 2012 May 1 it is in a 366 x 368 km orbit, almost 100 km lower (and now below the orbital altitude of the ISS). It is coming down at an increasingly fast speed, as the diagrams below show (based on orbital calculations by Mike McCants, derived from amateur observations which include my observations):

click diagrams to enlarge

 

Current Decay Prediction

Using Alan Pickup's SatEvo software with the current orbit and solar activity, I expect the reentry of IGS 1B to occur somewhere during a window that spans from June until August. As the orbit is evolving fast, it is pertinent that we keep close track of the object in order not to lose it (a few days old elements already results in several minutes uncertainty in pass time).

UARS re-entry Update (and Nanosail-D, and IGS 1B)

UARS update: It seems that the re-entry moment for UARS, the defunct NASA Upper Atmosphere Research Satellite, is moving forward in time, as Harro Zimmer pointed out on the Seesat-L list.

NASA and SSC Space-Track both settle for a decay on or near 24 September, and so do independant analysis by Harro Zimmer as well as my own assessment (using Alan Pickup's SatEvo software with current 10.7cm flux values).

As the orbital development near decay is highly influenced by solar activity, there currently is an uncertainty of possibly up to a few days in these predictions. Yet it seems save to say that UARS has not much more than a week left.

Nanosail-D update: Meanwhile, that other NASA object up there slowly coming down, NASA's experimental solar sail Nanosail-D, seems not quite willing to give up. It's current orbit and current values for 10.7cm solar flux suggest it will hang on at least another month, untill late October. Same caveats as for UARS apply.

IGS 1B update: this defunct Japanese spy satellite which is steadily coming down (see earlier post here and earlier posts linked their in) since it malfunctioned in 2007, likewise seems intend on spending some more time up there. The current orbit plus solar activity now give a nominal re-entry prognosis for early 2013 instead of 2012. This date is certainly still going to shift back or forth considerably however, depending on how solar activity develops.

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...

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:

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

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.

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

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.

click image to enlarge

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.

More on the IGS 1B fuel tank, and the (reduced) risk of it re-entering

At the end of the previous weekend, I posted an extensive post on the malfunctioned Japanese spy satellite IGS 1B (03-009B). It malfuntioned in 2007, has subsequently lost orbital altitude, and is now expected to re-enter early 2012.

The concerns was, that it might have a still partly filled fuel tank - potentially creating a risk at re-entry, a concern similar to that for the re-entry of USA 193 in 2008 (which, for that reason, was destroyed on-orbit by a SM-3 missile). This greatly worried me, the more as no news on this was appearing from either the Japanese, or US Space Command (who no doubt must have been aware that IGS 1B was coming down - an object like this will certainly be tracked).

My assessment of a potentially still half-full tank, was, as I indicated, at best an "educated guess". Noted amateur observer Ted Molczan from Toronto has now made an independant assessment of the situation, notably on the absolute amount of fuel left. Below I quote from his analysis, in which he writes (after first noting that he gets similar results to mine as to the probable time of decay, i.e early 2012):

"I agree that IGS 1B could decay from orbit in 2012, with perhaps half of its initial fuel mass; however, I believe that its initial fuel mass probably was far less than that of USA 193 - between approximately 28 kg and nearly 100 kg, compared with the 450 kg of USA 193. If half of IGS 1B's fuel has been expended, then between 14 kg and 50 kg may remain - at most 10 percent of USA 193's fuel load. Only the Government of Japan knows for certain the quantity of fuel that remains, but if my estimate is in the ballpark, then the risk of an uncontrolled decay from orbit would be much less than for USA 193."

[...]

"USA 193 carried about 450 kg of fuel, none of which had been expended by the time of its impending decay, due to its failure soon after it reached orbit. I believe that IGS 1B may have considerably less fuel for the following reasons:

1. IGS 1B was designed to operate at a considerably higher altitude than USA 193 (485 km vs. 360 km), which means that it was subject to far less atmospheric drag, which would have decreased the quantity of fuel required for orbit maintenance.

2. IGS 1B's total mass is reportedly about half that of USA 193 (1200 kg vs. 2300 kg). For a given velocity change, the fuel expenditure varies in direct proportion to total spacecraft mass.

3. IGS 1B died four years into what was reportedly a five year mission, so might already have expended most of its fuel."  

[note from Marco Langbroek: but its sister ship IGS 1A is still maintaining orbit 8 years later, as I indicated in my original post, suggesting that these satellites carry more fuel than for a minimum 5 year mission]

"With respect to points #1 and #2, assuming that IGS 1B's ballistic coefficient (mass divided by cross-sectional area) is similar to that of USA 193, and that its fuel supply was designed to enable operating up to twice the reported 5 year design life, i.e. 10 years, then the total velocity change required to maintain 485 km altitude would have been about 53 m/s (metres per second). Assuming IGS 1B uses the same fuel as USA 193, then for its mass of 1200 kg, the required initial fuel mass would have been just 28 kg - far less than that of USA 193.

Factoring in point #3: assuming provision of fuel for 10 years operation, then IGS 1B might have consumed 40 percent of its fuel by the time it died, four years after launch. Considering that its first couple of years of operation coincided with the tail end of the  previous solar maximum, its fuel use could have been somewhat greater; assuming for the sake of argument that half its fuel has been expended, then 14 kg would remain.

I based this rough estimate on data found in the respected textbook/reference Space Mission Analysis and Design III, specifically the annual velocity change required to maintain low Earth orbits against decay, depending on altitude, ballistic coefficient and solar activity. I assumed that fuel for attitude control was negligible, and that IGS 1B was not designed to be de-orbited at the end of its useful life (the latter would have increased the initial fuel mass to nearly 100 kg, with perhaps 50 kg remaining after four years of operation, still far less than USA 193 carried.)"

I have high trust in Ted's assessment: and the result is somewhat of a reassurrance: 14 to 50 kg of fuel is an order of a magnitude less than the 450 kg of fuel of USA 193. While no uncontrolled re-entry is without danger, these figures from Ted's assessment lead me to think that IGS 1B is clearly less of a threath than USA 193 was.

Ted's assessement is exactly the kind of thing I called for in my earlier post, when I wrote:

Instead of watching this one quietly go down, I would prefer to see a good risk assessment done [...] a clear argument presented as to why it would not be a danger in this case, given all the fuzz created around falling fuel tanks with USA 193.

Ideally, this should of course have come from the Japanese themselves (which refused to say anything pertinent to one of the reporters that contected me over this, besides the simple statement that there was "no risk"). In absence of that, Ted's assessment is a good thing to have.

Yet another Japanese satellite failure!

The Japanese, already suffering from the major devastation of the recent earthquake, truely don't seem to catch a break.

Today news broke that yet another Japanese radar- and optical satellite has broken down on orbit. It concerns ALOS, a non-classified Earth Observation satellite including radar, visual and infrared sensing equipment.

This comes after the 2007 malfunction of the classified SAR satellite IGS 1B, which is now developing into a re-entry hazard concern for 2012 (as discussed extensively on this blog in a post from last weekend): and the 2010 malfunction of their other classified SAR satellite, IGS R2.

In the aftermath of the recent earthquake, losing their prized remote sensing satellites must really be a pain for the Japanese: this is all really at the most untimely of moments.

Unlike IGS 1B, ALOS is not a direct re-entry hazard for the near future. In a 697 x 694 km orbit (notably higher than that of the IGS-es), it will take a considerable time for it to decay.

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:

click image to enlarge

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

click image to enlarge

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.

NROL-34 recovered!

NROL-34 code-named ODIN is a classified payload launched by the NRO on 15 April 2011 (last Friday), 04:24:10 UTC. The launch itself was called FRIGGA, see the launch and mission patches here.

Initially suspected to be a Trumpet destined for a Molniya orbit by independant analysts, a change of mind was promoted short before the launch by new information that suggested it to be a new NOSS pair. NOSS stands for Naval Ocean Surveillance System, and the newer NOSS typically consist of two satellites forming a close tandem.

After the launch of NROL-34 on April 15, the hunt was on to recover it: and hence for me it was very frustrating to see that a period of cloudy skies ensued at Cospar 4353!

Initial attempts by several observers to locate it according to orbit estimates published by Ted failed (see here and here). Then Mike reported an observation of what could be the NOSS duo from Texas on April 17, prompting a new orbit estimate. However, several other observers plus Mike himself next failed to recover it according to this orbit estimate (see here, here, here and here). So, the situation was very unclear: where was NROL-34, and what did Mike see?

Independant of each other, BWGS president Bram Dorreman in Belgium and me in Leiden, the Netherlands, turned back to Ted's initial orbit estimate, for a prolonged orbit plane search, yesterday evening: Bram visually, and I used the camera. This was the first clear evening allowing this. Conditions were poor, as the only potentially visible pass was very low in the west (20 degrees altitude), with a very poor phase angle and hence expected low brightness. I therefore decided to use the EF 2.8/100 mm Macro lens, as this picks up fainter objects - the trade-off is however a smaller FOV. I started the photographic survey at 20:05:20 UTC, making a continuous series of 10s exposures separated by 10 seconds each, and ended at 20:13:00 UTC.

On the 4th exposure (20:06:22.30 - 20:06:32.35 UTC), a very faint trail showed up. The trail is extremely marginal in quality, barely visible above the background noise: but it turned out to be one of the two NOSS objects (the leading one, probably) of the elusive NROL-34!

Below is (a part of) the image, with the very faint, barely visible trail marked by arrows at the start and end (you might have to adjust your monitor settings to see it, and definitely need to click the image below to full size):

click image to enlarge

After measuring the image, and finding no match to a known object, I privately mailed to Ted and Mike (and inadvertently switched the trail ends in that proces, initially reporting the trail end as the first position and the trail start as the second, instead of the correct other way around: a revised, correct report can be found here). The object passed about 4 minutes earlier than the nominal predicted pass time from Ted's initial NROL-34 elset estimate.

Meanwhile, it turned out, Bram in Belgium had visually (binoculars) picked up the same object, as well as a second object trailing it by 16 seconds. The latter probably was too faint to be photographed, as it was not visible on my images.

Based on a quick revised search orbit from Bram and my observations, Ted next picked it up a few hours later from Toronto in Canada, and Kevin Fetter observed it from the USA as well, as did Tim Luton.

So, three days after launch NROL-34 finally has been recovered. The game can now begin to further refine the orbit, and monitor any subsequent manoeuvres. The new NOSS has been given the provisional designation NOSS 3-5 by our group of amateur observers.

Later that evening, I observed IGS 1B (03-009B: see my post on the expected re-entry of this object a year from now here) and the KH-12 USA 186 (05-042A), as well as (as strays) a duo of Globalstars, Globalstar 4 (98-008D) and Globalstar 37 (99-012D), trying to impersonate a NOSS (as if the evening wasn't already confusing enough!).

[UPDATED] Another Malfunctioned Spy Satellite is Coming Down - with Hydrazine onboard

UPDATE (24 Apr 2011): in a separate post, I discuss a new analysis by Ted Molczan, who has done an independent assessment on the absolute amount of fuel left in the tank of IGS 1B. This assessment, in which I have a large degree of trust, suggests that the absolute amount of fuel carried by IGS 1B is substantially lower than was the case with USA 193. This is somewhat of a reassurance. Read more about it in the separate post here.

Summary - this long post discusses the imminent uncontrolled re-entry of the malfunctioned Japanese spy satellite IGS 1B (2003-009B) in the first half of next year (2012): and points out that there might be a potentially hazardous half-full tank of fuel still in the defunct satellite, mimicking the situation with USA 193 in 2008.

Prologue - Three years ago: USA 193 and 'Operation Burnt Frost'

Three years ago, a malfunctioned US Spy Satellite called USA 193 (2006-057A) made headlines, when it was destroyed by a modified SM-3 missile fired from the USS Lake Erie near Hawaii. This was done in order to avoid a potentially dangerous uncontrolled re-entry early 2008 (see my coverage of the story here). According to US Government officials, the tank with toxic Hydrazine fuel onboard the satellite was the main reason for this unusual and spectacular pre-emptive destruction code-named "Operation Burnt Frost", although a few independant analysts (e.g. Yousaf Butt) maintain that the real motives were instead to prevent cutting edge technology from falling in the wrong hands, and perhaps also to provide a symbol warning to the Chinese. The Chinese had conducted a succesfull anti-satellite test (ASAT) a year earlier which greatly worried the USA. The suggestion that it was not the potential hydrazine hazard but another motive that prompted the decision to destroy USA 193, was hotly debated, notably by noted Space journalist Jim Oberg who strongly defended the official position (for more examples of the heated discussion, see here).


2012: IGS 1B, Another Spy Satellite Coming Down

Now, three years later, another malfunctioned spy satellite is coming down. And like USA 193, it likely too has a significant reserve of fuel left in it's onboard tank.

Image below: the doomed malfunctioned satellite IGS 1B, a bright naked-eye object, photographed by the author from Leiden (the Netherlands) on 21 April 2011

click image to enlarge

The satellite in question is a Japanese spy satellite, IGS 1B (2003-009B), believed to weigh 1.2 tons (about one-third of the weight of USA 193). It was launched on a H-2A rocket on 28 March 2003 together with a sister satellite, IGS 1A (2003-009A). IGS stands for Intelligence Gathering Satellite, an English translation of the Japanese designation joho shushu eisei.

Both satellites, placed in similar ~488 km, 97.3 degree inclined Polar orbits, were meant to work in tandem, the IGS-A object being an optical imaging reconnaissance satellite, the IGS-B object a Synthetic Aperture Radar (SAR) reconnaissance satellite with imaging resolutions believed to be in the order of 1 meter. Their mission -and that of subsequent similar IGS satellites launched- probably was and is primarily to keep an eye on North Korea's Ballistic Missile program, as well as providing an imaging aid in case of natural disasters occuring in Japan.

In order to carry out their mission, these satellites carefully maintain a very stable sun-synchronous orbit by means of frequent small manoeuvres. While some sources (including the CIA) list an intended life-span of 5 years, the optical satellite of the pair (IGS 1A) appears to be still actively maintaining its orbit as of April 2011, over 8 years after launch of the pair, indicating that these satellites probably have a significant amount of fuel onboard to enable these orbit maintenance manoeuvres.

Both objects in question are classified, meaning that neither the Japanese government nor the US Government make orbital elements available. Amateur trackers, including this author, have however kept track of both objects since their launch, determining and updating their orbits (periodically published here).


March 2007: Loss of power, and loss of altitude, by IGS 1B

In the spring of 2007, the Japanese government made public that the radar satellite of the pair, IGS 1B, experienced a serious malfunction involving loss of power on or near March 25, 2007.

Indeed, amateur tracking data show that since March 2007 the satellite has stopped the careful maintainance of its orbit and instead has started to lose altitude. In addition, amateur trackers (including this author) started to report an irregular brightness behaviour of the satellite, including some spectacular flares not seen prior to 2007 (e.g. reports here, here, here, here, here and here), indicating a loss of attitude control.

The following diagram, created by this author based on published orbital updates calculated by Mike McCants from amateur tracking data (including data by this author) shows how the Mean Motion of the satellite, initially constant near 15.26 revolutions/day (the sun-synchronous value for inclination 97.37 degrees), has gone up steadily since late March 2007 (this date, the date of the reported malfunction, indicated by a vertical dashed grey line), indicating a loss of altitude. For comparison, the values of IGS 1B's still operational optical sister satellite IGS 1A, are shown as well (note how they remain constant due to the constant orbital maintenance manoeuvres this satellite continues to make):

click diagram to enlarge

Indeed, the perigee and apogee altitudes of the satellite as derived from the published amateur orbits, show a clear and increasing drop in altitude from March 2007 onwards (unlike the constant values of its still operational sister craft IGS 1A, shown as a reference in the diagram as well). Since the 2007 malfunction, the orbital altitude has already decreased by over 30 km, and the decrease is continuing at an increasingly fast pace:

click diagram to enlarge

As the loss of altitude starts right at the moment of the reported malfunction (late March 2007), it appears to be a malfunction affecting control of the satellite itself, not just it's radar system. With this is meant that the loss of altitude and start of orbital decay does not appear to be due to a controlled shut-down sometime after the remote sensing equipment malfunctioned. Instead, it appears that the Japanese operators have indeed truely lost control over the satellite.


When will it re-enter?

At the current increasing rate of orbital decay, it is clear that the satellite is now entering its last year of existence. Using Alan Pickup's orbital evolution software SatEvo and the latest IGS 1B orbit updates by McCants, IGS 1B's re-entry into the atmosphere is predicted to occur in about a year from now, around March, April or May 2012.

These predictions will probably shift a bit back or forth in the future, as the orbital evolution depends on a.o. solar activity (which is not constant and not well-predictable). But it is clear that somewhere in the first half of 2012, IGS 1B will come down.


Issues connected to the uncontrolled re-entry of IGS 1B

Similar to what was the case with the now infamous USA 193 satellite, the situation is that we have a satellite in a Polar orbit and likely containing a still significant reserve of fuel about to come down in an uncontrolled fashion.

Normally, when a spy satellite in Low Earth Orbit is at the end of its life, the last reserve of fuel is used to make the satellite deliberately re-enter in a controlled fashion, over a carefully chosen spot: usually the Pacific Ocean, where the re-entry can do no harm. This was recently done with the US radar spy satellite Lacrosse 2 for example (see here).

With a satellite that is out of control, like the infamous USA 193 and now this Japanese IGS 1B, that is however not possible. The satellite can basically plunge down anywhere on earth, and when remnants survive this re-entry, they can become a danger if the re-entry happens to occur over an inhabited area.

The latter danger was the official rationale behind the decision to destroy USA 193 in 2008 by means of a missile fired from the USS Lake Erie, just before the satellite would have come down on its own. Especially the fact that, due to the early malfunction of this satellite, there still was a tank with a considerable reserve of toxic hydrazine fuel on board, was given as a reason for the "shoot-down" (actually more of a "shoot-to-pieces"): the operation was called "Operation Burnt Frost" because the stated objective was to destroy the hydrazine reserve which, after two years of inactivity of the satellite, was likely frozen.

With IGS 1B, we might be facing a similar hazard in 2012. The satellite is bound to have a fuel reserve left, and quite likely a considerable reserve at that. (note added 24/04/2011: see however the post here, featuring an independant re-assessment by Ted Molczan)

IGS 1B passing through Canis venatici and the tail stars of the Big Dipper on 9 April 2011

click image to enlarge

As mentioned earlier, some sources list an intended life-span of 5 years for IGS 1B (and IGS 1A). It malfunctioned after 4 years, so one can expect that as a minimum there is at least enough fuel for a year left in the spacecraft.

But there are reasons to believe that the reserve of fuel left could in fact be considerably more than that.

The reason to think so is that, as mentioned earlier in this post, eight years after launch the IGS 1B sister craft IGS 1A is still actively maintaining it's orbit (see diagrams above). Mid-2008, the spacecraft manoeuvred to re-allign it's inclination to the 97.37 degree inclination orbital plane of subsequent IGS satellites launched from 2006 onwards. This indicates that 5 years after launch, it was (and up to this day probably is) still fully operational, and being primed for continued tasks. A CIA summary suggests an operational replacement by another IGS satellite was not effected untill at least mid 2010, over 7 years after its launch. As mentioned, amateur tracking data show that IGS 1A is still actively maintaining it's orbit as of April 2011, 8 years after its launch.

The implication is, that these IGS spacecraft actually have enough fuel reserves onboard for over 8 years of operation. As IGS 1B malfunctioned after only 4 years in operation, the implication of that in turn is that half or more of the original fuel reserves could still be left in the spacecraft (one factor however not easily calculated in with this, is the amount of fuel spent in the initial manoeuvering to obtain the desired orbit directly after launch).

That, a tank potentially still half full, is a considerable amount of fuel. (note added 24/04/2011: see however the post here, featuring an independant re-assessment by Ted Molczan)


Should action be taken?

The potential hazard of the onboard reserve of hydrazine fuel upon impact on earth was given as the primary reason to mount "Operation Burnt Frost" with USA 193 in 2008. As we might now be facing a similar situation with IGS 1B, it will be interesting to see if a similar drastic measure is taken, either by the Japanese (who own the same SM-3 missile system used for 'Operation Burnt Frost') or it's ally the USA, given that the latter has previous experience with such a complicated exercise. And if not, then the question will be: why in the case of USA 193, but not in the case of IGS 1B?




As was the case with USA 193 in 2008, the doomed IGS 1B satellite is in a polar orbit. It has a 97.3 degree inclined orbit, meaning that it is a potential danger to every latitude between 82.7 degree North and 82.7 degree South. This range of latitudes covers every inhabited spot on Earth, including all of the USA, Canada, Europe, Australia, Africa, Asia, South America and Japan.

While the amount of fuel left in IGS 1B is probably not as large (in the sense of amount of gallons) as it was in USA 193, a considerable amount of it nevertheless is very likely there, in the shape of what could be (note: in a "worst case scenario") up to a half full (and frozen) tank that might survive re-entry. Here, I should however mention that of course my assessment on the tank content is at best an "educated guess", and I could of course be wrong (only the Japanese can answer that point). (note added 24/04/2011: see however the post here, featuring an independant re-assessment by Ted Molczan)

Instead of watching this one quietly go down, I would prefer to see a good risk assessment done and either mitigating action taken, or a clear argument presented as to why it would not be a danger in this case, given all the fuzz created around falling fuel tanks with USA 193.



Note added: according to the Japanese press, a second IGS radar satellite (IGS R2, 2007-005A) suffered a system failure in August 2010, 3.5 years after launch.

note: this post has been slightly edited in the afternoon of April 20, to better reflect the point that the "tank half full" assessment for IGS 1B is a "worst case scenario". Japan should give some openness in information to replace these "educated guesses" by more solid facts.

IGS 5r flaring, and more USA 129 KH-12 in perigee

Over the past week I was able to observe on April 8, 9 and 12. I already reported on my April 9 observations of the new USA 227 (NROL-27) geostationary SDS here.

On April 12, I observed the Japanese optical reconnaissance satellite IGS 5A (09-066A) and the rocket that launched it, the IGS 5 rocket (IGS 5r, 09-066B), as well as the old American experimental satellite MSX (96-024A).

To my surprise, the IGS 5 rocket treated me on a bright slow mag 0 flare at about 20:43:27 UTC while it was making a pass in the east, near the tail of the Big Dipper. Below image shows the slow flare, with as an inset a second image made 20s later, showing it at its more usual brightness:

click image to enlarge

MSX displayed a brief modest flare as well (mag. +1) at about 21:28:43 UTC.

IGS 1B (03-009B), another, older (and now defunct) Japanese IGS, was captured as well ( I will post more on IGS 1B shortly, probably at the end of next weekend, as it is coming down within a year from now):

click image to enlarge

The KH-12 optical reconnaissance satellite USA 129 (96-072A) was still making near-perigee passes over the SatTrackCam observatory, resulting in fast passes and long trails. I had to revert to the 24 mm wide-angle lens to avoid the object running out of the FOV.

Below are two images showing it ascend over the rooftop of the SatTrackCam observatory. The first image shows it in the front body of Leo: the second image shows the head and front body of Leo at left, Castor and Pollux in Gemini at right, the head of Hydra in the bottom, and the trail of USA 129 close to the M44 (Praesepe) cluster in Cancer:

click images to enlarge

Hollidays, Ötzi, a Deluge, and USA 179 (SDS 3-3)

For most of the month August, I have been out of the country, to Northern Italy. With my GF I visited Bozen/Bolzano in the Italian part of Tirol, to see Ötzi the glacier-mummie; then made a 2-week backpack hike through the Dolomite mountains, going from refugio (mountain hut) to refugio; and next visited Verona and Venice. In all, a very fine 3-week hollidays!

Shortly after getting back, I managed some limited observations on August 24: USA 186 and the USA 179 r.

Two days later, on the 26th of August, a deluge hit my country including Cospar 4353. An incredible amount (for our country) of precipitation fell: in places thsi amounted to over 140 mm, over 2 times the monthly amount, in only a few hours time. Especially in the east of the country, this led to floods and associated water troubles.

At Cospar 4353, some 60 mm of rain is the monthly normal for August. On the night 25-26 and morning of the 26th, in just 18 hours time, 78 mm of rain was recorded by the pluviometer of my weather station. Most of it fell in an hour time around 9:00 am.

click diagram to enlarge

The days following this deluge, were mostly bad with clouds and rain. I managed to resume observations on the evening of August 30th, taking advantage of a short but bright clearing. Target was USA 179 (SDS 3-3), a US military communication satellite in a Molniya orbit.

As it turned out, the satellite was quite off in position compared to (at that time) a 25 days old elset. It was 3.4 degrees south of the predicted position:

click images to enlarge

image made with Heavensat

I followed the object over the next nights, 31 Aug, 1 Sep and 2 Sep, in order to provide data for an orbital update. On August 31, the object was again snagged during a short but bright clearing, this time in Cepheus and closer to it's apogee. Below is a single image and a stack of the 4 images obtained:

click images to enlarge

Compare the single images of 30 and 31 August, and to the stack of the August 31 to the stack of the September 2 images, all shown here at the same scale (full pixel resolution).

click image to enlarge

The difference in angular speed at different parts of it's orbit is well visible.

Other objects imaged these nights were the STSS Demo 1 + 2 objects; MSX, IGS 1B, and on Sept 1 the Russian Progress-M 06M cargoship that had just been decoupled from the ISS the previous day.

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

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

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):

click image to enlarge

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

click diagram to enlarge

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

click image to enlarge