Monday, 20 October 2025

[MULTIPLE UPDATES] Possible Space Debris found near Newman, Australia on Oct 18, might be Jielong 3 upper stage remains

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On 18 October 2025 near 14:00 local time (= 18 October ~6:00 UTC), a strange object was found on or near a dirtroad in the outback of  the Pilbara region in Western Australia. The object, suspected to be space debris, was found some 30 km east of the small mining town of Newman, as reported by ABC.

The object (photo's in the ABC report) resembles a COPV (Composite-Overwrapped Pressure Vessel), a type of space debris that often survives reentry. It reportedly was burning when found (this seems to be visible in the first photograph in the ABC report), which is unusual and against expectations for space debris. Nevertheless, the character of the object and a good match of the find location to a reentry on 18 October does persuade me to conclude that this is space debris indeed.

A possible candidate for the origin of this apparent space debris is a Chinese Jielong 3 upper stage, catnr. 61237, COSPAR 2024-173L. This object reentered on October 18, although (again! See this recent reentry) no TIP was issued by CSpOC.

I identified the object (note: so independently did Ravi Jagtiani) by assuming the report it was burning, although odd, is true, indicating a very recent impact. Using the latest orbital catalogue I first checked which objects were in orbits below 250 km on October 17-18, i.e. close to reentry, and next I ran a SatEvo analysis on this set to further cull it down to objects that should have been near reentry around that time. Starlink satellites could be excluded given the character of the debris. This left only a handfull of candidates. Of these, only one was in an orbit that would match passing close to Newman in the early hours of October 18: the mentioned Chinese Jielong 3 stage in a 97.6 degree inclined polar orbit. Using a standard SGP4 propagation as a first check, the ground-track would pass some 20-30 km east of Newman around 4:40 UTC on October 18. The rocket stage approached from the north-northeast moving towards the south-southwest.

The last available orbit for 2024-173L is for epoch 25291.03873492 (18 Oct 00:55 UTC), a few hours before the Newman object was found. Using that orbit as a starting point and deploying the reentry model we recently created in the open source Delft University of Technology Astrodynamics Toolkit (Tudat), I tried whether I could get a reentry trajectory to end ~30 km east of Newman. 

Not much information is known about the Jielong 3 components in terms of size and mass: therefore, estimates for size and mass of the upper stage had to be used. I assumed a size of about 1.5 x 1.5 meter (cf Jonathan McDowell's catalogue) and then by trail-and-error varied the mass to get an impact point as close to 30 km due east of Newman as possible.

An impact point situated directly ~30 km east of Newman results when I use a mass of ~301 kg, which seems a reasonable value for a small solid fuel upper stage build from composite. The two maps below show the Tudat modelled reentry trajectory that results from a 2.5 m2 drag surface and 301 kg mass, with impact just after 4:40 UTC on 18 October (see also update II at the bottom of this post):

 

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The modelled impact time is 1 to1.5 hours before the object was reportedly found. 

So it looks like the Jielong 3 upper stage 2024-173L is a good candidate for the origin of the possible space debris object found near Newman on October 18. Rather than a COPV from the stage, it could actually be (a significant part of) the upper stage itself, given the large size that the photo's suggest (and also given that the Jielong 3 upper stage is reportedly a solid fuel stage).

As we have seen with a number of recent reentries, CSpOC alas did not provide a TIP for this object (TIP = "Time of Impact Prediction", the reentry prediction by the CSpOC reentry model). They did however release an administrative "decay message" for 2024-173L for October 18 just after the reentry, indicating that it did reenter that day.

 

UPDATE I, 21 Oct 2025 00:20 UTC:

An EU-SST reentry analysis for the Jielong 3 upper stage 2024-173L is in good agreement with my Tudat analysis.

 

UPDATE II21 Oct 2025 15:45 UTC:

Using Tudat, I tried to fit the orbital evolution (based on US tracking data) for 2024-173L from July 1, 2025 to October 15, 2025 to the Tudat model, playing with mass and drag area, to get at empirical values for mass and drag area. One of the solutions that fits well is a mass of 300 kg and drag area of 2.2 m2 , which is close to the values I used to get it to reenter near Newman as described earlier in this blogpost. 

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With a 300 kg mass and 2.2 m2 drag area, the Tudat reentry model has it nominally surviving untill ~5:17 UTC ± 65 min, nominally reentering half an orbital revolution after passing Newman: but passing Newman actually is well within the uncertainty window of this reeentry prediction (the blue line on the map shows the trajectory over the uncertainty window):

 

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In other words: this too suggests that the object found near Newman could be (a part of) the Jielong 3 upper stage 2024-173L.

 

UPDATE III, 31 Oct 2025: 

A lone TIP has suddenly been issued for 2024-173L by CSpOC today: 18 Oct 2025 4:38 ± 1m UTC near nominally 18.1 S 121.2 E.  

This conforms well to the space debris being found in Newman, as the time and location likely are based (given the ± 1 minute uncertainty) on a satellite observation of the fireball, i.e. on the location at an altitude of 80-100 km. I have plotted the position in the map below, that also depicts our Tudat reentry trajectory with associated times.

 

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Friday, 17 October 2025

[UPDATED] Identifying a reentry over the Canary Islands on 16 October as the reentry of the Chinese satellite Xinjishu Yanzheng 7 (XJY-7)

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In the early local morning of 16 October 2025 around 1:56 UTC, a spectacular phenomena appeared in the sky over Tenerife in the Canary Islands. A bright, slow, fragmenting fireball moved from south to north over the sky. Sonic booms were heard and registered by several seismic stations on Tenerife. The event clearly was a reentry of artificial space debris. For footage, see here and here. The all-sky image on the left above is from the Izana Atmospheric Research Center on Tenerife (the plotted sky map on the right is by me, for comparison, see discussion below).

I was alerted to the event by my Spanish colleague Josep Trigo (ICE-CSIC/IEEC) in the morning of October 16, who asked if I could identify which object was reentering here. A check on the CSpOC portal Space-Track did not yield a TIP that would match - as it turns out, the object in question never received a TIP, which is odd as it was heavy and large, as we will see.

So in order to identify it, I had to do some additional research. I selected all orbits from the orbital catalogue with perigee below 200 km. Next, I used SatEvo software to see which of these orbits would have a predicted reentry on October 15-16. From the handfull of candidates left, I next checked which of them would be over the Canary Islands near the time of the event (1:56 - 1:57 UTC on 16 October 2025). One object stood out - and it was one for which no TIP had been issued: the Chinese satellite Xinjishu Yanzheng 7 (XJY-7, 2020-102C), launched in 2020.

All sky imagery showing the reentry trail in the sky against a starry background had meanwhile been published on Twitter by the Izana Atmospheric Research Center on Tenerife. The general location of the trail amidst the stars in the sky and the direction of movement matched those expected for XJY-7 well. It was clear we had found our culprit.

Not much is known about XJY-7. Jonathan McDowell lists bus dimensions of about 3 x 5 x 9 meter and a dry mass near 3000 kg for this object in his catalogue. ESA's DISCOS lists similar dimensions but a mass of 5000 kg (perhaps a wet mass).

The last available orbit for XJY-7 was for epoch 25288.77158679, or 15 October 18:31 UTC, some 7h 25m before the event. To investigate further, I used the reentry model that my colleague Dominic Dirkx and I made some time ago (see earlier posts) in the Open Source Delft University of Technology Astrodynamics Toolkit (Tudat) to see whether I, with trial-and-error, could get a reentry model for XJY-7 to end over the Canary Islands. As it turns out, I could, for a mass of 2717 kg (close to 3 tons) and a drag area of 37.44 m2 (the maximum drag surface listed by DISCOS), using past and current space weather.

The map below shows the resulting reentry groundtrack and times for this model integration. Note that the model does not take fragmentation and mass loss into account, so it has limitations and is an approximation only. I had the model terminate at 20 km altitude.

The figure below the map, compares the sky trajectory resulting from this model for the location of the Izana Atmospheric Research Center, to that registered by the all sky camera at Izana. They match well.

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It is curious that no TIP was issued for this reentry by CSpOC. This was a large heavy object: 3 x 5 x 9 meter and 3 tons in mass. CSpOC apparently overlooked this reentry - a few hours post reentry, they however did add an administrative "decay message" for October 16 to the catalogue for this object, but without any further details. 

We recently have seen a complete lack of TIP's being issued for any object, for over a month. Only recently, CSpOC resumed issuing TIP's. CSpOC is currently clearly having some issues with their system. Luckily, we were nevertheless able to identify the object responsible for this spectacular reentry, by some diligent analysis.

 

UPDATE 17 Oct 2025  22:00 UTC:

Click map to enlarge (map updated to correct typo)

I played a little bit more with the reentry model, tinkering the area to mass ratio to get an even better fit to the sky trajectory as seen from the Izana camera station. Here is an updated plot of the modelled sky trajectory (numbers next to trajectory are atmospheric altitudes in km according to the simulation):

A mass of 2715.5 kg creates a very good fit, except for the end of the trail. That is no surprise: the reentry model is a simple model without mass loss and fragmentation, while in reality there is massive mass loss and fragmentation (meaning: changing area to mass ratio's for various fragments). When solid parts survive, heavy relative to their size, these have a lower area to mass ratio meaning they lose altitude less quickly.

Here is the improved model trajectory overlayed on the Izana camera image:

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(I thank Josep Trigo (ICE-CSIC/IEEC) and the Spanish SPMN for data and discussions)