Progress M-27M is down!

click map to enlarge

According to US military tracking data from JSpOC, the out of control Progress M-27M cargoship that should have brought supplies to the ISS, re-entered over the southeast Pacific near 51 S, 87 W, moving towards Tierra del Fuego, on May 8 at 02:20 UT, +- 1 minute.

The map above shows its approximate re-entry position. Remember: re-entry in reality is a process that takes several minutes, during which it moves along the shown track (shown track is the last orbital revolution plus a small part of the track in front of the nominal re-entry position).

Several analysts believe that re-entry times given to a plusminus of only 1 minute by JSpOC are based on Space-based detections by the US military's SDP DSP and SBIRS infra-red early warning satellites. These detect and geolocate the infra-red signature of the fireball caused by the re-entry.

In this particular case, this is the more likely because the last three published orbital element sets from (we assume) regular tracking facilities are clearly not too accurate. So the very short uncertainty interval in the re-entry time given, must be based on some other unpublished data source.

The clear problems with the last few element sets issued is one reason why I did not make any further forecasts after the one I issued at 18:30 UT yesterday, 8 hours before the actual re-entry.

My prediction at that time (2:03 UT +- 2 hrs, which I rounded to 2:00 UT +- 2 hrs given the uncertainty interval) actually is not that far off from JSpOC's final re-entry time.

Meanwhile, official Russian ROSKOSMOS sources give a re-entry time that is 15 minutes earlier (and very similar to my prediction hours before) than that suggested by US military tracking sources. The Russians state re-entry at 2:04 UT (5:04 Moscow time) over the central Pacific south of Hawaii (red dot on the map above). This is likely to be a 'forecast' (or 'aftercast' rather) based on tracking data and/or telemetry obtained during the hours before. No uncertainty interval is given.

[UPDATED] Progress M-27M re-entry predictions

[predictionlast updated 7 May 18:30 UT]
[update 8 may 2015: NEW post  about the re-entry HERE]

I am providing occasional estimates for the uncontrolled re-entry of Progress M-27M on my Twitter feed today. Likewise, several other people are providing estimates, of which I would want to recommend those by Ted Molczan on the Seesat mailing list. You will note that the re-entry predictions will vary from source to source!

My current estimate is for re-entry to occur:

between 17 and 22 UT on May 7
between 21:10 and 01:30 UT  May 7-8

between 00:00 and 04:00 UT May 8

(estimate update issued 7 May, 18:30 UT based on elsets up to epoch 15127.69084936 processed with Alan Pickup's SatAna and SatEvo software).

Within this window, the slightly more likely moments are around and just after perigee passage, i.e. the tracks over the Pacific in this case.


The estimate may still change as new orbits are released. Previous released elsets initially strongly pushed the estimated re-entry time back from early May 8 to late May 7, as the result of solar activity yesterday and the resulting effects on the outer Earth atmosphere. As a result, my earlier estimate of this morning (May 7) overestimated the decay rate. With the new orbital update from epoch 15127.50860911 and onwards things are settling towards more realistic values, with a trend of slightly moving the decay window to a later time.

Above is a rough map of where the re-entry might occur, based on current uncertainties.

For updates, keep an eye on my Twitter feed.

[update: final re-entry results have been posted in a new post here]

Tweets door @Marco_Langbroek

ATV-4 and ISS, 15 hours before docking (and Progress too)

After a few cloudy and rainy days, it miraculously cleared in the afternoon of the 14th. This allowed me a last view on the ATV-4 before docking to the International Space Station ISS.

click image to enlarge

I observed two passes. The first was in very deep evening twilight (sun at -6 degrees altitude) at 22:56 local time (20:56 UT). ISS and ATV-4 passed almost right overhead, the ATV slightly over 2 minutes in time behind ISS and both easily visible. I had set up my video equipment, but forgot to press the "record" button....

The next pass was under a darker sky, at 00:32 local time (22:32 UT). I walked a few tens of yards to the city moat to see it (I have better view at low elevations there). ISS and ATV-4 attained a maximum elevation of 28 degrees in the S-SW. The photograph above is from that pass. Using the 2.8/17-50 mm Tamron at the 17 mm setting, I could just catch ISS and ATV in one image - with a stray old Russian military satellite as a bonus (Kosmos 1315 (1981-103A), a defunct Tselina-D ELINT launched in 1981. A Japanese H-2A r/b briefly became bright as well and is visible in some images (but not the one above).



I had also set up the video, filming from my GF's appartment. About 16 minutes before the ISS pass, I filmed Progress M-19M (2013-007A). This cargoship, now filled with trash, was undocked from the ISS a few days ago to make room for the ATV. It will reenter on June 19th. In the video above, while the Progess is passing, look for a brief bright flash just below the image center at 22:13:36. This is a flashing geostationary satellite (probably NSTAR A, 1995-044A). The video next cuts to the ISS pass 16 minutes later, followed by ATV-4 and a couple of bats in the last seconds of the video.

The image below is a stack of 28 photographs, showing ATV-4, the ISS, Kosmos 1315 (barely) and the H-2A r/b (top):

click image to enlarge

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

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.

Progress-M 04M, MSX, and Mentor 2

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

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

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

click image to enlarge

Progress-M 04M on 26 and 29 June:

click images to enlarge

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

click image to enlarge

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

click image to enlarge

ISS and Progress chasing each other

This evening I finally was able to see the ISS and the recently decoupled Progress M-02 M (09-024A) cargoship chasing each other over the sky. The couple was some 20 degrees apart, with the Progress leading. A very neat sight.

The Progress was around +2.5 to +3, ISS attained about -3.5 and was distinctly orange. The photo below shows the couple while still low in the sky, ascending in the west.

I also observed USA 161 (01-044A) passing east some 10 minutes later.

(click image to enlarge)

Observing ISS and two of its Progress cargo spacecraft

Yesterday evening was very clear, and provided the rather unique opportunity to see the International Space Station (ISS) pass in twilight, followed several minutes later by two of its cargo Spacecraft: Progress-M62 (07-064A) decoupled from ISS on Wednesday and now moving away from it carrying garbage, and Progress-M63 (08-004A) launched from Baikonur in Kazachstan on Wednesday and on its way to the ISS with fresh cargo. Seeing two Progress spacecraft in free flight on the same evening is unique.

ISS was the first to pass, still in deep twilight, at 18:15 local time, being around mag. -3. Five minutes later Progress-M62 followed on a trajectory a few degrees higher, grazing the Hyades cluster, and being about mag. +1. And twelve minutes after that, the newly launched Progress-M63 followed in a very similar trajectory. By that time, although the sky was still bright due to twilight, it was dark enough to try to photograph it. The resulting photograph has a very bright background drowning the trail, but after some image manipulation for brightness and contrast it is visible:

(click image to enlarge)

I logged a point for Progress-M63 through the telescope, and the endpoint of the trail on the image above provided a second point.

Later in the evening I observed Lacrosse 2 (91-017A), which by now was 34.6 seconds early, the USA 32 ELINT sat (88-078A), Lacrosse 5 (05-016A) and the NOSS 3-2 duo (03-054A & C), the latter duo on two consecutive passes.

Like previous days it was again clouded in the morning, so no chance to observe USA 193.

Tomorrow evening is going to prove very interesting, I hope. The weather prospects are good, and if the launch isn't postponed this evening, I will have a very good 80 degree post-twilight pass of Space Shuttle Atlantis STS-122. In addition, the ISS and the two Progresses can be observed again. Plus, the Soyuz rocket booster (08-004B) from the Progress-M63 launch could prove very interesting, as it will make two passes (one visible and one in shadow) while close to decay.