Saturday, 31 January 2026

You Only Die Twice (redux): the unusual and confusing double reentry of a ZQ-3 upper stage (2025-282A)

Click map to enlarge


The uncontrolled reentry of a large (assumed 7-8 ton weight) Chinese ZQ-3 (Zhuque-3) upper stage, 2025-282A (catnr. 66877), on 30 January 2026 for some reason created quite some public attention, especially in Europe. But  the event became decidedly unusual when, nine hours after the US Space Force published the Final TIP, a second Final TIP appeared. We have not seen that happening before. 

So what do we have here: an object that reentered TWICE?

The first published "final" TIP, published about an hour after the listed reentry time, was for 30 Jan 2026, 12:39 UTC ± 1m, near 54.3 S, 170.4 W. 

This time and location incidentally where a very close match to the final result of the experimental Tudat reentry model we were running for this object at Delft University of Technology (nominal 12:39 UTC, 56.0 S, 179.3 W, see here).

Jonathan McDowell and I believe that the final TIP's with a quoted 1-minute uncertainty are in fact based on space-based (satellite) observations of the reentry fireball, so they are accurate (and refer to the object starting to ablate at roughly 90-80 km altitude).

So far so good: observed and modelled reentry moment well in agreement. Nice!

But then it got confusing. Several hours later that day, the US Space Force published a second "final" TIP, also with a quoted 1-minute accuracy: 13:43 UTC ± 1m, near 3.9 S, 60.7 E. This is half-a-revolution (1h 4m) later than the first TIP.

 

Screenshot of the two relevant TIP's as published on Space-Track

 

Both locations are indicated by the yellow circles in the map in top of this post (the blue cross is the nominal result of our Tudat reentry model, the solid blue line the one-sigma uncertainty in that estimate).

So what happened here? How did this object appear to reenter TWICE?

While it could all be a clerical error or a mix-up/false detection, I suspect that this unusual "double reentry" is genuine. This particular reentry was from a somewhat eccentric orbit, more so that your average reentry. The last available orbit from ~2 revolutions before the 12:39 UTC TIP, was 211 x 102 km, with apogee decidely higher than perigee. Under such circumstances, parts might surve a low perigee (low enough to initiate ablation and partial reentry).

My suspicion therefore is that when the object initially reentered in perigee at 12:39 UTC and started to ablate and break up, a single more massive/solid part survived this perigee and continued for half a revolution, before finally reentering at 13:43 UTC.

(alternatively, you could think of this as one reentry with a very, very long stretched debris strewnfield)

The longer surviving part might well be the dummy payload of this experimental launch, which remained attached to the ZQ-3 upper stage but might have separated from the upper stage during the 12:39 UTC perigee/reentry. If this dummy payload was a solid weight, meaning it had a  much larger mass relative to area than the rest of the object, it might have survived and come out of perigee again, while the actual upper stage meanwhile did not survive this perigee and reentered in the first spot at 12:39 UTC. The dummy payload then finally came down in the second spot at 13:43 UTC.

Although a different situation, it reminds me a bit of a confusing case from 2014, the reentry of a Russian Kobalt-M spy satellite (on which I also wrote under the title "You Only Die Twice"  at the time, a blogpost which you can read here). The latter consisted of the uncontrolled reentry of shed parts over the US, preceded by a controlled reentry of the film return capsule over Russia a few hours earlier. So a different situation, but equally confusing.

Monday, 8 December 2025

NROL-77, probably a new NOSS (or maybe not)

click map to enlarge

On 9 December 2025 between 19:06 and 19:28 UTC, SpaceX will launch the classified mission NROL-77 for the NRO, from SLC-40 in Cape Canaveral. The NRO Press Kit is here.

Navigational Warnings point to initial launch into a ~49 degree inclined coasting orbit. Upon passing the descending node of that parking orbit, about an hour after launch, the Falcon 9 upper stage with payload will manoeuver into a ~63.4 degree inclined orbit, likely ~1000 x 1200 km. The upper stage deorbits at the end of the first revolution, in the eastern Pacific.

I initially briefly comtemplated a higher, more unusual orbit, at 1950 km altitude, based on the ~14 minute daily shift backwards of the launch window (as gleaned from Navigational Warning NAVAREA IV 1337). That was an overinterpretation (I blame the COVID infection I suffered the past week, it messes with the brain): the NOSS-like 1000 x 1200 km orbit is more likely and it fits the location and shape of the upper stage deorbit area well.

So this could be a new NOSS (Naval Ocean Surveillance System) duo of SIGINT satellites. Or maybe not, after the experience with NROL-85 in 2022 (see earlier blog post here) which featured only one payload, not two as is typical for NOSS missions. We'll see.

Below are the relevant Navigational Warnings, and two search orbits, one for the coasting orbit (valid untill ~1 hour after launch), the second for the payload(s). 

 

040948Z DEC 25
NAVAREA IV 1337/25(11,26).
NORTH ATLANTIC.
FLORIDA.
1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 
   091906Z TO 092010Z DEC, ALTERNATE
   101852Z TO 101956Z, 111838Z TO 111942Z,
   121824Z TO 121928Z, 131810Z TO 131914Z,
   141756Z TO 141900Z AND 151742Z TO 151846Z DEC
   IN AREAS BOUND BY:
   A. 30-50.00N 078-10.00W, 32-12.00N 077-07.00W,
      32-27.00N 076-28.00W, 32-03.00N 075-57.00W,
      31-38.00N 076-07.00W, 30-40.00N 077-57.00W.
   B. 28-39.69N 080-38.17W, 28-52.00N 080-15.00W,
      28-45.00N 080-03.00W, 28-29.00N 080-22.00W,
      28-27.61N 080-31.56W.
2. CANCEL THIS MSG 151946Z DEC 25.//

 

040904Z DEC 25
NAVAREA XII 789/25(21,22,83).
PACIFIC OCEAN.
1. HAZARDOUS OPERATIONS, SPACE DEBRIS
   1731Z TO 2200Z DAILY 09 THRU 15 DEC
   IN AREA BOUND BY
   12-02.00N 112-31.00W, 12-58.00N 114-47.00W,
   00-49.00S 120-38.00W, 01-46.00S 118-25.00W.
2. CANCEL THIS MSG 152300Z DEC 25.//

 

Search orbits:

NROL-77 PARKING                 for launch on 9 Dec 2025 19:06:00 UTC
1 70000U 25999A   25343.79583334  .00000000  00000-0  00000-0 0    03
2 70000 049.1163 258.3583 1136647 049.6536 329.5142 13.42495109    02

NROL-77 NOSS payloads           for launch on 9 Dec 2025 19:06:00 UTC
1 70001U 25999A   25343.83680556  .00000000  00000-0  00000-0 0    03
2 70001 063.4415 271.5212 0133723 213.5444 360.0000 13.42495109    02


 

image: NRO

 (with thanks to Ted Molczan for discussions)

Friday, 14 November 2025

BRIK-II is no more

On 12 November 2025, the Netherlands' first military satellite, the 6U cubesat BRIK-II (2021-058F), reentered into the atmosphere after 4 years of service. I posted about the launch and the backgrounds of this experimental small satellite in 2021.

 

BRIK-II during construction. Photo: Dutch Ministry of Defense

 

At TU Delft, we have been running a reentry model for BRIK-II in the open source TU Delft Astrodynamics Toolkit (Tudat). While for many weeks the prognosis from our model pointed steadily to 14 or 15 November 2025, things changed in the last few days when a strong series of geomagnetic storms developed, due to a series of strong solar flares. This (along with suspected attitude loss, causing a higher - and variable-  drag area) speeded up the reentry, as can be seen by the dramatic shift in the evolution of the reentry prediction during the last few days before reentry in the diagrams below:

 

click diagrams to enlarge

Our last estimate, based on the last available orbit from 12 November ~6:04 UTC, is that the cubesat reentered around 15:47 ± 1.9 hours UTC on November 12, 2025. 

The quoted error margin might, in fact, be a bit optimistic in this case, due to the unusually rough circumstances around the time of the reentry (which included the arrival of a shockwave from a X5.1-class solar flare). A more safe guess is reentry between ~11:45 and 19:45 UTC. The last available orbit on which our final forecast is based, dates from about 10 hours before the nominal reentry time from our model.

The map below shows the nominal reentry position plus the trajectory over the one- and two-sigma uncertainty interval in the prediction: 

click map to enlarge
 

BRIK-II, named after the very first aircraft of the Royal Netherlands Air Force in 1912 ("Brik"), was a trailblazer for the Dutch Air and Space Force. It was an experimental satellite, meant to show that operating satellites was possible for the Dutch military, and was a way to gain the Dutch Air Force valuable experience with such operations. Three other, operational, satellites would follow in the next four years: the joint Dutch-Norwegian satellites Huygens and Birkeland, and a SAR satellite.

Brik-II (the name means, a.o., "brick") truely paved the way into Space for the Dutch Air and Space Force.

 

BRIK-II imaged on-orbit by me on 30 March 2023


(on a related note: I have started to post experimental reentry forecasts for selected objects here: https://reentry.langbroek.org)

Monday, 20 October 2025

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

click map to enlarge

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):

 

click map to enlarge

 

click map to enlarge

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. 

click diagram to enlarge

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):

 

click map to enlarge

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.

 

click map to enlarge