THE SECRET SPIES IN THE SKY - Imagery, Data Analysis, and Discussions relating to Military Space
SatTrackCam Leiden (Cospar 4353) is a satellite tracking station located at Leiden, the Netherlands. The tracking focus is on classified objects - i.e. "spy satellites". With a camera, accurate positional measurements on satellites of interest are obtained in order to determine their orbits. Orbital behaviour is analysed.
This blog analyses Missile tests too.
The image above is a stack of twelve 4-second exposures taken with a Canon EOS 80D and EF 2.8/24 mm lens, and shows the Crew Dragon FRAM-2 passing over the domes of the historic Leiden Observatory in the evening of 2 April 2025.
FRAM-2 is a commercial ("space tourist") mission using a SpaceX Crew Dragon launched into a 90.0-degree inclined Polar Orbit at approximately 430 km altitude. It is the highest inclination of any crewed space mission so far. The spacecraft has four astronauts onboard: Chun Wang, Jannicke Mikkelsen, Rabea Rogge and Eric Philips.
click image to enlarge
I observed the spacecraft on April 2 and 3, 2025. On April 2, on a 35-degree
elevation evening twilight pass in the east, it reached magnitude +2.5
to +2.0. On April 3, on a high pass in the west, it was fainter, around
+3.5 to +4.
Here is a single image from the series I shot on April 2 (4-second exposure at ISO 800):
Click image to enlarge
Below image is from the April 3 pass and shows both FRAM-2 and two Chinese satellites, as well as an unidentified object in a 49-50 degree orbit (possibly a Starlink or Starshield satellite). The "smudge" in the image is a lens reflection caused by the nearby moon:
On 24 March 2025 at 17:48 UTC, a Falcon 9 blasted off from Cape Canaveral launch pad 40 in Florida as NROL-69, carrying the classified USA 498 payload to orbit for the National Reconnaissance Office (NRO).
About two hours later, the launch caused a spectacle in the skies over Europe, as a bright spiral-shaped cloud formed in the sky, moving along the track of the Falcon 9 upper stage from the launch. This was due to the Falcon 9 upper stage venting excess fuel, in preparation for reentry over the Indian Ocean about half an hour later, following a deorbit burn over the northern Atlantic.
The cloud of fuel droplets vented by the rocket stage was at an altitude of about 1000 km, where it was still in sunlight, causing it to shine brightly in the sky. The spiral pattern is due to the rocket stage spinning around is major axis, in order to stabilize the orientation of the stage in space. This is very typical for Falcon 9 upper stages and has been seen quite a few times now.
Prior to launch, Navigational Warnings seemed to indicate an initial launch into a 51-52 degree inclined orbit for NROL-69, followed by a burn into an approximately 64.4 degree inclined orbit.
Initially I interpreted the trajectory as featuring a 'dogleg' manoeuver into 64.4 degree inclination just after launch. I later revised that, following reports from observers in Poland that they saw the Falcon 9 during its first pass over Europe, 25 minutes after launch, in a trajectory more consistent with still being in a 51-52 degree inclination orbit. In addition, reports came from western Australia about a possible remnant exhaust cloud that might have been seen there about an hour after launch.
I therefore revised my interpretation of the launch sequence. My revised interpretation features an initial insertion into a 51-52 degree coasting orbit, followed by an insertion burn into 64 degrees inclination near the ascending node, about an hour after launch, over the Indian Ocean near western Australia. Following that, and following orbit insertion of the payload, the deorbit burn for the Falcon 9 upper stage happened over the northern Atlantic just after completion of the first revolution, and next the fuel venting seen from Europe around 20 UTC (21 CET), some two hours after the launch, during the first part of the second revolution. Deorbit of the Falcon 9 was around 20:40 UTC, 1.5 revolutions after the launch, over the Indian Ocean southeast of Madagascar (see map in top of this post).
Below are the Navigational Warnings for the launch. The hazard areas
from these warninsg are plotted in red in the map in top of this post.
191844Z MAR 25 NAVAREA IV 332/25(11,26). WESTERN NORTH ATLANTIC. FLORIDA. 1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 241742Z TO 241824Z MAR, ALTERNATE 251728Z TO 251810Z, 261714Z TO 261756Z, 271700Z TO 271742Z, 281646Z TO 281728Z, 291632Z TO 291714Z AND 301618Z TO 301700Z MAR IN AREAS BOUND BY: A. 28-38.31N 080-37.17W, 28-51.00N 080-14.00W, 28-44.00N 080-03.00W, 28-30.00N 080-18.00W, 28-27.40N 080-31.49W. B. 30-14.00N 078-53.00W, 31-58.00N 077-03.00W, 32-18.00N 076-17.00W, 32-02.00N 075-57.00W, 31-15.00N 076-21.00W, 29-55.00N 078-35.00W. 2. CANCEL THIS MSG 301800Z MAR 25.
190258Z MAR 25 HYDROPAC 711/25(61). INDIAN OCEAN. DNC 02, DNC 03. 1. HAZARDOUS OPERATIONS, SPACE DEBRIS 1849Z TO 2058Z DAILY 24 THRU 30 MAR IN AREA BOUND BY 23-06.00S 060-45.00E, 24-22.00S 058-21.00E, 54-18.00S 084-05.00E, 53-02.00S 087-47.00E. 2. CANCEL THIS MSG 302158Z MAR 25.//
As 64.4 degrees is the typical inclination for a NOSS (Naval Ocean Surveillance System) duo of SIGINT satellites, and given the location and timing of the deorbit area for the upper stage, my initial suspicion was that this could be a new NOSS launch into a 900 x 1300 km 64.4 degree inclined orbit. I was wrong in this however.
Two days after the launch, in the evening of March 26, a number of European observers (Tomi Simola in Finland, Eelke Visser and me in the Netherlands, and David Brearley in the UK) managed to find the payload on-orbit, close to my search orbit. Only one object could be detected, indicating that it is not a NOSS but something else. Below is a stack of several video frames showing the object (video itself is at the end of this post):
click to enlarge
The payload, now named USA 498, was detected in a 64.1 degree inclined, ~700 x 1500 km orbit (but this is based on a very short arc so the exact orbital altitude is still up for revision). We have not seen something in this kind of orbit earlier, apart from
NOSS satellites (the closest in orbital similarity otherwise is USA 327
(2022-040A), in a 1076 x 1135 km 63.4 degree inclined orbit).
The plot below shows its orbit and orbital position for the time of my March 26 observation:
Click image to enlarge
Below is some of my video footage from March 26, showing the payload as an object of about magnitude +5 to +6 (the instrument was a WATEC 902H2 Supreme with 1.2/50 mm lens):
I have written before on this blog about the Russian military SIGINT satellite LUCH (OLYMP-K) 2 (2023-031A). It was launched on 12 March 2023, and like its predecessor LUCH (OLYMP-K) 1, it has since moved about along the geostationary belt, doing proximity operations near western commercial geostationary satellites.
Each two to four months, it is moved to a new target, where it stays in close proximity until moved to a new target again, behaviour in a similar fashion to the US satellite PAN/NEMESIS-1 in the past. It is probably clandestinely accessing and monitoring communication streams of the target satellites, and perhaps mapping contact networks. It can sometimes come very close to its target, to within a few to a few tens of kilometers (that is very close in space).
From September 2024 onwards it was positioned at 0.93 W close to Intelsat 1002, but on February 7, 2025, it started a drift eastwards. After a significant one-month drift over 62 degrees in longitude, it settled again on March 7 near 62 E, its new eavesdropping target being Intelsat 39 (2029-049B). This latest move is the largest since it was launched.
Due to a combination of flu, moonlight and the fact that the new position is barely above the eastern horizon for me, I have not been able to image it in its new position yet.
The diagram above shows the various repositionings of LUCH (OLYMP-K) 2 since it was launched. Since launch, it has taken up the following positions:
PERIOD LONG. NEAR 21-03-2023 24-03-2023 78.00 E (checkout) 07-04-2023 02-05-2023 58.00 E (checkout) 22-05-2023 25-09-2023 9.00 E EUTELSAT (KA SAT) 9A, EUTELSAT 9B 04-10-2023 04-12-2023 3.20 E EUTELSATt 3B 05-12-2023 26-03-2024 2.60 E EUTELSAT KONNECT VHTS 01-04-2024 22-06-2024 4.75 E ASTRA 4A 01-07-2024 16-09-2024 0.54 W THOR 7 18-09-2024 07-02-2025 0.92 W INTELSAT 1002 07-03-2025 62.02 E INTELSAT 39
In the early morning of February 19, 2025, near 3:45 UTC (4:45 CET) scores of people in the Netherlands, UK, Germany and Denmark saw a slow, fragmenting object move through the sky. The event garnered much attention.
Above is a video of the event obtained by the camera of @dutchspace.bsky.social in the Netherlands. Another stunning video, by the meteor camera of André Knoeffel in Brandenburg, Germany, is here. The video below is by Nick James from the UK, and shows the start of the reentry near 03:43 UTC and start of fragmentation.
The event was caused by the reentry of a SpaceX Falcon 9 upper stage, object 2025-022Y (cat nr 62878) . This upper stage, from the Starlink group 11-4 launch from Vandenberg, California, on 1 February 2025 23:02 UTC, 18 days prior to the reentry event, failed to deorbit in a controlled way after launch and payload insertion. It was supposed to do a deorbit burn after releasing the payloads, and deorbit over a specified area in the Pacific Ocean around 00:45 UTC on Feb 2, near the end of the first revolution (see map below). With the deorbit failed, it however stayed on orbit for almost 3 weeks, and then had an uncontrolled deorbit over NW Europe on February 19.
click map to enlarge
The general character of the Feb 19 event (slow, fragmenting) as well as time and location fit well with the Falcon 9 upper stage reentry. The CSpOCfinal TIP for this reentry (which we suspect is based on a satellite observation of the reentry fireball) is 19 February 3:43 UTC ± 1 min, near 52.8 N, 5.6 W. The reentry trajectory runs over the British Isles, the northern Netherlands, northern Germany and Poland.
Below is the ground-track for the last orbit up to reentry, and a detail of the approximate final reentry track over Europe, with the Netherlands indicated in red:
click map to enlarge
click map to enlarge
A possible piece of debris has been found at Komorniki near Poznan in Poland, media reports. The object on the photograph looks like a Composite Overwrap Pressure Vessel, a component of the Falcon 9 upper stage that has survived reentry before, e.g. in March 2021 when a Falcon 9 upper stage reentered over Washington. The location of the find matches well with the reentry trajectory, as can be seen in the map above. [update: reportedly another one of these composite-wrapped pressure tanks was subsequently found in Poland]
The event caused a lot of media attention: I did several media interviews on the reentry, amongst others with two Dutch national tv channels.
In two contributions to The Space Review (part 1 here and part 2 here) for the first instance, as well as two follow-up blog posts for later manoeuvers (here, and here), I analyzed three periodic orbit raising manoeuvers by the North Korean military reconnaissance satellite Malligyong-1 (2023-179A) done in February, June and September 2024. They followed a similar pattern: an orbit raise (orbit maintenance manoeuver) in five daily increments, all taking place on late evening passes (13 - 14h UTC = 22 - 23h local time) passes over North Korea.
Now Malligyong-1 has manoeuvered for a fourth time. And while there are some similarities, this time the followed pattern was different.
The orbit raising manoeuver was done between 2025 January 16 and 18, a month later than I had anticipated. However, as can be seen in the diagram above, it was this time done in three daily increments, not five as was the case in previous orbit raising events.
Compared to the previous orbit raises, the raise during each daily increment was larger, some 2.5 km per increment rather than 1.2 km as in the previous cases, for a total orbital altitude raise of about 7.5 km, which is also somewhat larger than the previous orbit raises (which was 4 km in February 2024 and 6 km in June and September 2024). As during the previous orbital altitude maintenance raises, it brought back the orbital altitude to the initial value from November 2023, when the satellite was launched. See the diagrams below:
click diagram to enlarge
click diagram to enlarge
The three sequential manoeuvers between January 16 and 18 raised both apogee and perigee. The daily rate of RAAN precession is still very close to the ideal sun-synchronous value.
click diagram to enlarge
As was the case for all previous orbit raises, the times I reconstruct for the three incremental orbit raises correspond to the orbital plane of Malligyong-1 passing over or near North Korea (for the method used, see here);
# DATE UTC LAT LON ORBITS USED FOR ANALYSIS RAISE M1 16-01-2025 13:14 28.6 N 53.4 W 25016.48110101 25017.33556354 2.50 km M2 17-01-2025 12:52 19.4 N 46.3 W 25017.33556354 25018.12465384 2.51 km M3 18-01-2025 12:33 20.5 N 41.7 W 25018.45348685 25019.24307946 2.52 km
However, there is a clear difference: all nominal positions do not plot near North Korea this time, but over the mid-Atlantic. Nominal manoeuver times were about half an hour before passing over/near North Korea.
The map below plots the nominal manoeuver positions I reconstruct, as well as a part of the ground trajectory from 10 minutes before to ten minutes after the nominal reconstructed manoeuver time.
click map to enlarge
The red circle in the map is the area where the satellite would be above
the horizon as seen from Pyongyang. Clearly - and unlike previous
occasions - the manoeuver points do not coincide with this area,
although the satellite would pass through the area about 30 minutes
after the reconstructed manoeuver moments (for one of the manoeuver
moments, I depicted a longer part of the ground trajectory as well with
markers each 5 minutes of flight time).
The manoeuvers not conciding with the satellite being over the horizon as seen from the Pyongyang General Satellite Control Center (PGSC), is something new and intriguing. The nominal manoeuver points being over the mid-Atlantic is interesting.
So how where these manoeuvers initiated? Assuming my reconstruction of the manoeuver points is correct, here are three options, all having their own implications:
(1) use of a pre-programmed, automated orbit raising burn;
(2) an orbit raising burn command sent through a (Russian? Chinese?) relay satellite in GEO;
(3) an orbit raising burn command sent from a groundstation or ship near/around the mid-Atlantic.
The white area depicted in the map is from where a command from a ground station or ship should have been sent in the case of option (3), possibly a location in Brazil or the mid-Atlantic.
It might be interesting if someone better versed in that than me, could check the presence of North Korean vessels (and Russian and Chinese space tracking vessels) in the mid-Atlantic between January 16 and 18, 2025.
All three nominal positions correspond to a manoeuver just after passing
through the Ascending Node, which is often a standard practise with
orbit raising manoeuvers when smaller or larger alterations to the
orbital inclination are required. However, no such alterations to the
orbital inclination are apparent:
click diagram to enlarge
This was the fourth orbit rasing manoeuver episode since Malligyong-1 was launched on 21 November 2023. Here are they all in a table:
# period incr raise before afterinterval 1 2024 19-23 Feb 5x 4.0 km 498 km 502 km 90 days 2 2024 03-07 Jun 5x 5.7 km 497 km 503 km 105 days 3 2024 06-10 Sep 5x 5.9 km 498 km 504 km 95 days 4 2025 16-18 Jan 3x 7.5 km 496 km 504 km 132 days
A next raise might occur in the period April to June 2025. It will be interesting to see where those manoeuver locations will end up geographically and whether at some point the orbital inclination is adjusted or not.
the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency
the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency
the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency
On 30 December 2024, reportedly near 12:00 UTC, an odd object is believed to have fallen from the sky near the village of Mukuku in Kenia (approximately 1.58 S, 37.61 E, some 100 km from the Kenian capital Nairobi). It is metal ring of about 2.5 meter in size and reportedly 500 kg mass, although that mass could be an estimate only.
The Kenya Space Agency is investigating, believing it to be Space Debris. Apart from the metal ring in the pictures, other fragments looking consistent with space debris, for example what looks like carbon wrap and isolation foil, were found several kilometers away from it (see video below):
It is still not entirely clear if the object is space debris (although it looks likely), and if so, which object from what launch. There are two reentry candidates for this date, only one of which looks viable as a candidate (see also Jonathan McDowell's summary here).
That viable candidate is object 33155 (2008-034C), an Ariane SYLDA adapter from flight V184, the launch of ProtoStar 1 and BADR 6 to geosynchonous orbit on 7 July 2008. This SYLDA adapter was left in a 1.6 degree inclined GTO following the launch and had its reentry on or near December 30.
As I will investigate below, using a reentry simulation, both the location where the ring was found and the reported fall time are realistic for it to be this object.
CSpOC, the US military tracking network, last recorded 2008-034C in a
1923 x 146 km orbit on December 23, i.e. a week before the Kenia impact.
As this is a very low inclination orbit (1.56 degrees), it belongs to a
class of objects that is ill-tracked due to a lack of tracking stations
close to the equator. This explains the 1-week gap between the last
available orbit and the reentry.
As a note: what is a SYLDA? A SYLDA ("SYstème de Lancement Double Ariane") is a kind of hollow shell put over the first payload, in order that a second payload can be mounted above it.The conical upper part of the SYLDA has a smallest diameter near 2.6
meter, i.e. similar to the size of the ring found in Kenia, which then
could be an upper Payload Adapter Fitting (PAF).
A SYLDA (black) as part of a stage, satellite and fairing stack (image: ESA)
An Ariane SYLDA (image: ESA)
CSpOC issued a reentry TIP for this SYLDA for 30 December 2024, 21:38 UTC +- 59 minutes. That is the date of the Kenia event, but not the correct time, as the Kenia event reportedly happened near 12:00 UTC, nine hours earlier. However, the quoted uncertainty of 59 minutes from this TIP is not realistic, if based on the last available orbit (a week old at the time!). A more realistic uncertainty estimate would be +- 1.5 days.
Ignoring the CSpOC TIP time, I did an independent impact prediction, using the development version of the open source TU Delft Astrodynamics Toolbox (TUDAT).
I used the last available orbit (epoch 24358.42010446) and the nrlmsise00 model atmosphere to run a reentry prediction, using a trial-and-error approach to see whether I could tinker with the drag area such that it would reenter near 1.58 S, 37.61 E near 12:00 UTC on December 30.
From @DutchSpace on twitter, who is very knowledgeable on Ariane hardware, I got a mass of 505 kg for the SYLDA in question. The dimensions for the SYLDA on flight V184 should have been about 4.5 x 6.4 meter (there are different versions of SYLDA with different mass and sizes).
After some trial-and-error, I can make the object reenter at 1.57 S, 37.61 E on 30 December 2024 at 11:49 UTC, close to the reported location and time, if I use an average drag area of ~18.24 m2. That is a value which is about 63% of the maximum drag area of this SYLDA (roughly 28.8 m2). This is a reasonable value: during earlier reentry analysis for elongated objects like rocket stages (or in this case, a hollow elongated adapter), I found that a drag area of about 60% - 62% of the maximum area is usually a good approximation to account for the variability in drag due to tumbling .
Below is what the approach trajectory from this simulation would be:
click map to enlarge
While my TUDAT simulation does not prove that the object is debris from 2008-034C (SYLDA), it does show that it is feasible for the reported time and location.
How about that 'other' candidate? That was an Atlas Centaur booster, 2004-034B, for which CSpOC gives a TIP of 30 December 2024 21:30 +- 1 m UTC. However, the orbital plane of this candidate did not pass over Kenia at the reported time (12:00 UTC), and moreover, this object was still detected on-orbit several hours after the reported time of the Kenia event (see also Jonathan McDowell's analysis here): the last reported orbit is for epoch 30 December 2024 15:50 UTC (but it is always possible that a part came off earlier). For these reasons, it is not that likely that the Kenia event was due to a part of this object.
@DutchSpace on twitter, who as mentioned is very knowledgeable on Ariane hardware, so far has trouble positively identifying the ring as a SYLDA part (and that worries me). If the reported mass of 500 kg is correct, that is too heavy for it to be part of this SYLDA too. I have some suspicion however that the reported mass is an overestimate.
For now the verdict is: possibly the reentry of parts of the Ariane SYLDA 2008-034C, but not proven beyond doubt yet.
Here is the final output [revised after running both a TUDAT and TUDAT script update] of my TUDAT reentry model (I had it stop at 50 km altitude, as at that altitude the object should have completely fragmented and decelerated, with fragments falling down basically vertically):
mass: 505 kg drag area: 18.236375 m^2 altitude limit: 50000.0 meter
propagation start: 2024-12-23 10:04:57.030000 UTC propagation end: 2024-12-30 11:49:25.029545 UTC final altitude: 49.879
reentry after 7.072 days
REENTRY AT: 2024-12-30 11:49:25.029545 UTC lat: -1.57 lon: 37.61
Values in the last three lines are nominal only, the error margins over a 7-day integration period are large. Also ignore the superfluous digits. As a reminder: I tinkered with the drag area untill I got a value that made it reenter as close to 1.58 S, 37.61 E and 12:00 UTC as possible, and the above output gives the relevent drag area and the resulting modelled reentry time and location.
The TUDAT script used can be downloaded here (note: you have to use this script with the 'development version' of TUDAT, as the current non-development release of TUDAT has a bug where the epoch of a TLE is incorrectly read). The development version of TUDAT and installation instructions can be found here.
UPDATE 9 Jan 2025:
In a statement to Gaël Lombart of Le Parisien, Arianespace engineers have cast doubt on the identification of the crashed object as a SYLDA part, indicating that the size of the ring does not fit and stating that "this part does not belong to an element of a European launcher operated by
Arianespace". So the mystery remains as to what this object's origin is.
X-37B OTV 7 near apogee imaged by the author on 3 October 2024. Click to enlarge
It looks like the time on orbit is about to end for mission OTV 7 of the enigmatic US Space Force X-37B spaceplane (2023-210A). Launched on 29 December 2023, it went into an unusual Highly Elliptical Orbit with apogee near 38 600 km and perigee near 300 km and an orbital inclination of 59 degrees (see various earlier blogposts).
On October 10, the US Space Force announced that OTV 7 "will begin executing a series of novel maneuvers, called aerobraking, to
change its orbit around Earth and safely dispose of its service module
components in accordance with recognized standards for space debris
mitigation"
I already wrote earlier, e.g. in this blogpost from February, that the mission likely would end by using aerobraking in perigee to lower apogee, circularize in a Low Earth Orbit, and then land.
Aerobraking is a technique where, by a manoeuver in apogee, the perigee altitude of the orbit is lowered such that it is in the top of the atmosphere: not low enough to make it reenter, but enough to significantly slow it down. When the spacecraft goes through perigee in that situation, it experiences enhanced drag, that will result in drastically lowering the apogee of the orbit, certainly after a few of such perigee passages.
This will bring the orbit down and eventually change the Highly Elliptical Orbit character into a Low Earth Orbit. Orbital velocity near perigee (over 10 km/s while in a Highly Elliptical orbit with apogee near 39 000 km) will be drastically reduced (to 6.8 km/s) by this, allowing the vehicle to reenter the atmosphere and land without experiencing too excessive forces during reentry.
It looks like the process of lowering perigee might already have started around October 4, when for the first time perigee (while earlier just above 300 km) seems to drop below 300 km:
OTV 7 apogee and perigee altitudes over time. NOTE: logarithmic Y-axis! Click to enlarge
This is difficult to say for certain, as frequent larger and smaller manoeuvers by OTV 7 (it seems to have manoeuvered daily, as it never was on the ephemerids during a next observation) combined with a sketchy observational coverage (most of the observations from the last two months have been done by me, with some by Tomi Simola), means that orbit determinations are not always that easy and it is not clear how real the minor variations in perigee altitude from orbit determination to orbit determination are.
The wording of the US Space Force news item is such, that it seems to suggest that after apogee lowering and orbit circularization through aerobraking, OTV 7 might for a while continue its mission in a lower (Low Earth) orbit, as they write:
"Once the aerobrake maneuver is complete, the X-37B will resume its test
and experimentation objectives until they are accomplished, at which
time the vehicle will de-orbit and execute a safe return as it has
during its six previous missions".
So rather than land directly after the aerobraking sequence is finished, it might stay on orbit for days, weeks or months, in an orbit that is more like those of previous X-37B missions.
Over the past two months, perigee has been kept on the equator (argument of perigee kept near 180 degrees). That is a situation where during a perigee pass, there is the possibility to change the orbital inclination. So it is possible that near the end of the aerobraking sequence, the orbital inclination (currently 59 degrees) will be changed to a lower value, e.g. around 40 degrees as with previous X-37B missions in LEO.
As an interesting aside, the US Space Force bulltein also mentions that mission OTV 7 in its unusual HEO orbit "has conducted radiation effect experiments and has been testing Space Domain Awareness technologies in a Highly Elliptical Orbit".
