Saturday 13 April 2024

Russian ICBM test launch (Topol?) from Kapustin Yar seen from the Middle East

click to enlarge

On 12 April 2024 near 16:00 UTC, the Russian Armed Forces test-fired an unarmed ICBM from Kapustin Yar, targetting the test range at Sary Shagan at a distance of some 2000 km. The missile was likely a TOPOL-M.

In the image above, I have modelled the likely trajectory, assuming apogee at 1000 km altitude as in previous tests. Below is Russian MoD footage of the launch:


The missile launch was widely seen as a bright comet-like object in the sky, in Russia as well as in the Middle East, with reports from as far south as a.o. Iran and Iraq. As many there where in anxiety about an expected Iranian retaliation attack on Israel, it created  a bit of a stir.


In the aftermath, there were some people that expressed doubt whether a Russian ICBM test would be visible from the Middle East. So I reconstructed the area of visibility to show that it is in fact visible. 

In the map below, I have drawn isocircles around the estimated point of cut-off of the missile's third stage. That stage cut-off happened after 3 minutes of flight at an altitude of about 570 km (there is some leeway in both figures possible, but in general the figure below will give you a good indication of the area of visibility).

click map to enlarge


The isocircles give you the altitude in the local sky as seen from a region encompassing southern Russia and the Middle East. 

As can be seen, the area of visibility is large, and horizontally extends about 2600 km from the geographic location of stage engine cut-off, to as far as southern Iran. 

Bar the first few tens of kilometers, the trajectory was fully sun-illuminated, and as a result the exhaust clouds of the missile were also sun-illuminated, making them  shine brightly in the sky.

That exhaust clouds from the upper stages of missile launches can be seen over a avery large area isn't something new. Russian ICBM tests from Plesetsk have multiple times resulted in sightings of bright "spirals" in the Arctic sky (e.g. here). Chinese tests have also been observed, e.g. this example that was observed from South Korea in 2019, which I further analysed here. Meanwhile, the post-boost vehicles of ICBM's/SLBM's sometimes also cause visible phenomena in the sky: see my analysis of one such sighting from La Palma in 2013 related to a US Trident SLBM test for example.

Saturday 6 April 2024

A possible French Missile test over the Gulf of Biscaye on April 10-11

click map to enlarge

An odd Navigational Warning has appeared, for "space debris" along a 420-km trackline over the Gulf of Biscaye, from a point some 37 km southwest of Concarneau on the southern coast of Bretagne to a point some 20 km west of the French missile test base DGA Essais de Missiles near Biscarosse, southwest France. The Navigational Warning is for April 10 and 11, 2024, from 10:00 to 14:30 UTC (12:00 to 16:30 CEST).

I do not think this Navigational Warning is really about "space debris", but rather believe some sort of missile test is concerned

The southern end of the 420 km trackline being close to the French missile testing base at Biscarosse, while the northern end is in the area that the French Navy uses to test-launch SLBM's, is a giveaway that it rather concerns some kind of missile. Also, a controlled reentry of "space debris" so close to the French coast would be very odd. So I do not believe for a second that the Warning truely is for "space debris"

This is the text of the Navigational Warning:

051439Z APR 24
HYDROLANT 716/24(37).
DNC 08.
   101000Z TO 101430Z, ALTERNATE 111000Z TO 111430Z
   47-36.00N 004-13.00W, 44-20.00N 001-30.00W.
2. CANCEL THIS MSG 111530Z APR 24.

Because the trackline starts in the area that the French use for SLBM test launches, and because "space debris" would perhaps indicate something with a high apogee, my initial thought (see also the title of the map above) was that it might concern a test of a new SLBM stage (it is definitely not a full M51 SLBM test, the range is much too short for that and those tests fire westwards).

However, the 420 km length of the indicated track line, would also match two medium-range to long-range cruise-missiles of the French armed forces: the ASMP-A, which is airlaunched and meant to deliver a nuclear warhead; and the French-British SCALP-EG, also known as Storm Shadow, which is also air-launched and has a conventional warhead.

If it concerns a ship- or submarine-launched cruise-missile instead, then the MdCN would also be an option, but that missile would have a 2-3 times as large range.

Calling a cruise-missile "space debris" is a stretch however. So many open questions remain as to the character of the missile in question.

Wednesday 27 March 2024

NROL-70, likely an ADVANCED ORION satellite

NROL-70 launch trajectory. Click map to enlarge


On 28 March 2024, if weather cooperates (see update at bottom of post), ULA will launch NROL-70 from SLC-37 at Cape Canaveral, carrying a classified payload for the National Reconnaissance Office (NRO). 

NROL-70 will be the last launch of ULA's iconic Delta IV Heavy rocket. Navigational Warnings for the launch (plotted on the map above) indicate a launch to Geosynchronous orbit. The launch window opens at 17:40 UTC and runs to 22:51 UTC. Back-up dates are March 29 to April 1. 

The classified payload is likely Mentor 10 (Orion 12), a Signals Intelligence (SIGINT) satellite in the ADVANCED ORION class.

The NRO launch patch for NROL-70 features a Snow Leopard:


NRO launch patch for NROL-70


ADVANCED ORION/MENTOR satellites are very large. At magnitude +8, they are the brightest geosynchronous satellites in the sky. In a 2010 speech a former Director of the NRO, Bruce Carlson, called one of these, the NROL-32 payload (Mentor 5), "the largest satellite in the world". 

The satellites feature a very large parabolic unfoldable mesh antenna, with estimates of the size of this antenna ranging from 20 to 100 (!) meter. An NSA internal newsletter from 2009 that was leaked as part of the Snowden files, contains an artist impression of the satellite which indeed features a large mesh dish antenna:

ADVANCED ORION artist impression from a 2009 leaked NSA newsletter


These ADVANCED ORION satellites (also known as 'Mission 7600') are huge listening 'ears' in the sky, monitoring large areas for radio emmissions, notably military COMINT (communications) and FISINT, as outlined in this leaked NSA document.

Here is an image of one of these ADVANCED ORION satellites, Mentor 4, imaged by me in January 2020. Note how much brighter it is, due to its size, than the nearby commercial geosynchronous satellite Thuraya 2 (that it is close to this commercial telecom satellite is no coincidence, see my 2016 article in The Space Review linked below):


click image to enlarge

From the Navigational Warnings for the launch and what we know of earlier ADVANCED ORION launches (see my 2016 Space Review paper), NROL-70 will first follow a low altitude (~200 km) coasting orbit. Near the descending node, some 25 minutes after launch, it will then boost into a Geosynchronous Transfer Orbit, which some 6 hours after launch will deliver the payload to a Geosynchronous orbit.


NROL-70 launch trajectory. Click map to enlarge


It initially will likely be placed near longitude 100 E, over Indonesia and within range of the Pine Gap facility in Australia, where it will undergo checkout. It will then be moved to its operational slot, which is unknown.

Initial control will be from the joint US/Australian Pine Gap facility in Australia. Depending on where its operational position will be, control at some point might be handed over to RAF Menwith Hill in the UK.

More backgrounds on the role of these kind of SIGINT satellites can be found in this 2016 article in The Intercept and in my 2016 article in The Space Review.

Here is the text of the relevant Navigational Warning (the three hazard areas A, B and C have been plotted by me as red boxes in the map above):


191855Z MAR 24
   281740Z TO 282251Z MAR, ALTERNATE
   291737Z TO 292251Z MAR AND 011725Z TO 012251Z
   A. 28-34.73N 080-34.39W, 28-37.00N 080-20.00W,
      28-34.00N 079-44.00W, 28-30.00N 079-45.00W,
      28-28.00N 080-20.00W, 28-28.88N 080-32.26W,
      28-30.00N 080-32.80W, 28-33.65N 080-34.05W.
   B. 28-31.00N 073-23.00W, 28-22.00N 070-35.00W,
      27-51.00N 070-38.00W, 27-58.00N 073-22.00W.
   C. 22-05.00N 042-25.00W, 22-29.00N 042-17.00W,
      20-36.00N 036-57.00W, 20-22.00N 037-03.00W.
2. CANCEL THIS MSG 012351Z APR 24. 


Below are very approximate orbit estimates for the various phases of the launch. They are valid for launch on 28 March 2024, 17:40 UTC:

NROL-70 COASTING PHASE                        (valid 17:45-18:05 UTC)
1 70000U 24999A   24088.73611111  .00000000  00000-0  00000-0 0    06
2 70000 028.4000 281.1702 0007584 097.3393 339.7290 16.21678257    00

NROL-70 GTO PHASE                             (valid 18:05-23:30 UTC)
1 70001U 24999A   24088.75364583  .00000000  00000-0  00000-0 0    07
2 70001 028.4000 281.0464 7360043 179.7976 360.0000 02.21326367    09

MENTOR 10 initial placement guess              (valid from 23:30 UTC)
1 70002U 24999A   24088.98149645 0.00000000  00000-0  00000+0 0    02
2 70002   5.0000 278.2000 0001186 360.0000   2.0110  1.00277482    05

The last, Geosynchronous orbit assumes initial orbit placement at longitude 100 E at an initial orbital inclination of 5 degrees.

NRO Press kit for NROL-70
ULA Press kit for NROL-70


UPDATE 27 March 17:35 UTC:

Currently the weather forecast for 28 March does not look very positive, so launch might be postponed.

Wednesday 20 March 2024


click map to enlarge

In the early hours of March 21, at 6:40 UTC, Rocketlab will launch an Electron rocket from Launch Complex 2 on Wallops, Virginia. The launch, designated NROL-123 and nicknamed "Live and Let Fly", will carry three small classified experimental payloads into Low Earth Orbit for the National Reconnaissance Office (NRO) . 

Navigational Warnings suggest (initial) launch into a ~47.5 degree inclined orbit. The launch trajectory will pass very close to Bermuda (see map above). According to the Rocketlab Press kit, payload release is 54 minutes after launch, after approximately half an orbital revolution. As release is near the ascending node, it is possible that the kick stage will insert the payloads into somewhat different orbital inclination(s). Orbital altitude will likely be in the order of 600-700 km.

Little is known about the character of the payloads and the type of orbit does not give a clue either.  The NRO Press kit mentions that "NROL-123 will carry three collaborative research missions". The NRO Mission patch for NROL-123 features three hexagons with respectively a dragonfly, a sunfish (Mola), and wasps. The Rocketlab launch patch also similarly features a stylized dragonfly, a fish, and a wasp.


NROL-123 Mission patch (image: NRO)


The NRO Press kit says about these symbols that: 

"The dragonfly symbolizes energy, youthful exuberance, and accomplishment - representing the use of new technology. The position of it flying through the hexagon symbolizes a new frontier, new opportunity, and new perspective. The forward movement represents the critical path of the mission. The bees are based on the idea of “small but impactful” and represent the tremendous impact the program experiments will have on the NRO mission. The sunfish, or mola, nods toward the program". 

Which is all not very enlightening, especially where the meaning of the sunfish is concerned (and they should make up their mind if it are bees or wasps - they look like the latter to me).

Here is my very cautious estimate of the launch orbit. Orbital altitude is a bit of a guess, and there is some leeway in the orbital inclination possible too:

NROL-123                     for launch on 21 March 2024 06:40:00 UTC
1 70000U 24999A   24112.27777778  .00000000  00000-0  00000-0 0    05
2 70000 047.5000 101.3672 0002846 134.5077 326.5399 14.73474122    04

Below is the relevant Navigational Warning for this launch (see the map in top of the post for a plot of the indicated areas):

150916Z MAR 24
   210615Z TO 211030Z MAR, ALTERNATE 
   0615Z TO 1030Z DAILY 22 THRU 25 MAR
   A. 37-51.00N 075-30.00W, 37-52.00N 075-29.00W,
      37-56.00N 075-17.00W, 38-19.00N 074-35.00W,
      37-35.00N 074-11.00W, 37-15.00N 074-20.00W,
      37-23.00N 075-18.00W, 37-30.00N 075-29.00W,
      37-44.00N 075-30.00W, 37-48.00N 075-31.00W,
      37-49.00N 075-31.00W, 37-50.00N 075-31.00W,
      37-50.00N 075-31.00W.
   B. 35-02.00N 070-55.00W, 35-56.00N 069-54.00W,
      33-15.00N 065-46.00W, 32-19.00N 066-46.00W.
   C. 27-19.00N 061-16.00W, 27-54.00N 060-27.00W,
      24-27.00N 056-36.00W, 23-50.00N 057-26.00W.
2. CANCEL THIS MSG 251130Z MAR 24.

Thursday 14 March 2024

Reconstructing the approximate reentry and disintegration position of Starship FT3 [UPDATED]

click map to enlarge

Starship Flight Test 3 (see this earlier pre-launch post) was largely a success. Starship FT 3 launched from Boca Chica at 13:25 UTC (March 14, 2024) and was successfully inserted on a sub-orbital trajectory. The stage separations went well, coasting went well, and so did various other attempted milestones (such as briefly opening the cargo bay doors in space). 

There were a few small mishaps: an attempt to make a controlled water-landing of the first stage went awry, and so did the final controlled reentry attempt of Starship itself over the Indian Ocean. But in all, this was a successful test flight, providing exciting imagery during the launch and flight to boot (see end of this post).

In this post, I will try to reconstruct the approximate points of reentry: the point (at 100 km altitude) where the reentry plasma formation started, and the point were telemetry was lost (and Starship presumably disintegrated, at 65 km altitude).

The base of my reconstruction is this pre-launch TLE that I constructed for launch at 13:25:00 UTC:

STARSHIP FT3                 for launch on 14 March 2024 13:25:00 UTC
1 70000U 24999A   24074.55902778  .00000000  00000-0  00000-0 0    03
2 70000 026.3000 177.8817 0153183 289.7760 142.6230 16.45958778    07

I was able to check and calibrate this elset, making use of a prominent landmark on earth visible in the webcast just before reentry started. 

At Mission Elapsed Time (MET) 00:44:09, corresponding to 14:09:09 UTC, Lake Anony on Madagascar can be briefly seen:

screenshot from the SpaceX webcast at MET 00:44:09 showing Lake Anony 

The geographical area in question in a Google Earth image


This allowed to check with the trajectory based on my pre-launch estimated TLE. It shows that my TLE estimate basically puts the trajectory in the correct position, but that it is 27 seconds "late" on the real flight path, and a bit too low in altitude.

Two minutes later, at MET 00:46:17 (corresponding to 14:11:17 UTC), at 100 km altitude, the first clear reentry plasma can be seen forming as a red glow around the fins of Starship. This is reference point one:


Screenshot from SpaceX webcast. Click image to enlarge

Slightly over 3.5 minutes later, at 65 km altitude at MET 00:49:40  (corresponding to 14:14:40 UTC), telemetry is lost, and this presumably is where Starship disintegrated. This is reference point number two.

Knowing that my pre-launch TLE is 27 seconds "late", we can deduce approximate positions for reference point one (start of plasma formation) and reference point two (loss of telemetry and presumed disintegration) using the TLE.

They are at respectively 26.30 S, 55.68 E for the start of the Plasma formation, and 26.10 S, 70.87 E for telemetry loss and presumed disintegration, as indicated by the two yellow circles in the map below:

click map to enlarge

This also confirms that the controlled reentry aimed for the western part of the HYDROPAC 833/24 hazard zone (see discussion in my earlier pre-launch post here), as suggested by Jonathan McDowell, and that the eastern part of that zone was safety overshoot in case the controlled deorbit burn failed and Starship would continue on a ballistic trajectory.


UPDATE  15 March 2024 18:30 UTC:

I reanalysed the trajectory, using altitude data from the SpaceX webcast to create a TLE that matches the altitude against Mission Elapsed Time (MET), fits the hazard areas from the Navigational Warnings, and results in a pass south of Lake Anony in Madagascar at the correct MET:

STARSHIP FT revised elset                                -50 x 235 km
1 70012U 24999A   24074.55902778  .00000000  00000-0  00000-0 0    06
2 70012 026.3000 177.8795 0220000 355.7000 077.5000 16.67947166    01

As can be seen in the diagram below, this elset has a close fit to the altitudes from the SpaceX webcast (the blue dotted line is a polynomial through the altitudes from the webcast; the red crosses are the altitudes given by the TLE):

click diagram to enlarge

The resulting position for reference point one (start of plasma formation) is 26.28 S,  55.57 E. The resulting position for reference point two (loss of telemetry and presumed disintegration) is 26.13 S,  70.51 E.

click map to enlarge

The point where, 00:08:35 after launch, Starship started its coasting phase after engine cut-off is 24.491 N, 84.633 W (150 km altitude).

[end of update]

A few more images of the launch (screenshots from the SpaceX webcast):




screenshots from SpaceX webcast

Wednesday 13 March 2024

Starship Flight Test 3 upcoming

click map to enlarge

Pending FAA approval (i.e., the launch date might well be postponed), SpaceX aims to launch Starship Flight Test 3 this week. Navigational Warnings issued indicate a window opening at 12:00 UTC on March 14, 2024.

The flight trajectory differs from the previous two ill-fated test flights (which both disintegrated early in flight, see an earlier post here concerning FT 2). 

FT 1 and FT 2 targetted a splashdown near Hawaii after slightly less than one full orbital revolution. FT 3 however has a much shorter flight path, aiming to splash down in the Indian Ocean west of Australia after half a (sub-) orbital revolution.

The map above shows the hazard zones for the launch, from Navigational Warnings NAVAREA IV 278/24 and HYDROPAC 833/24, and the flight trajectory these indicate. Numbers next to the trajectory represent the approximate flight time in minutes after launch.

The hazard zone in the Gulf of Mexico differs from that of FT 1 and FT2  by being much more extended (perhaps a lesson from the last in-flight disintegration with fragments splashing down far downrange, near the Bahamas and the Dominican Republic: see an earlier blogpost here). It also has a remarkable shape - my tendency for pareidolia kicks in and sees a Plesiosaur in it. I wonder what the protrusions mean, especially the one near Florida and Cuba that appears to suggest a backwards motion. 

The reentry and splash-down hazard zone at the end of the flight path spans almost the full width of the Indian Ocean, starting near Madagascar and ending near Australia.

I estimate the following (sub-) orbit for the flight test:


STARSHIP FT3                 for launch on 14 March 2024 13:25:00 UTC
1 70000U 24999A   24074.55902778  .00000000  00000-0  00000-0 0    03
2 70000 026.3000 177.8817 0153183 289.7760 142.6230 16.45958778    07

 SpaceX has some ambitious aims for this flight test, which according to their website (as retrieved 13-03-2024) include:


"the successful ascent burn of both stages, opening and closing Starship’s payload door, a propellant transfer demonstration during the upper stage’s coast phase, the first ever re-light of a Raptor engine while in space, and a controlled reentry of Starship"

Let's however await first whether it actually does not have a RUD ('Rapid Unscheduled Disintegration') again early in flight, as FT 2 did... 

Note added 14 March 2024 9:50 UTC:

Jonathan McDowell has suggested to me that the controlled reentry likely aims for the western part of the Indian Ocean hazard zone from HYDROPAC 833/24, with the eastern part being a safety overshoot in case the deorbit fails. That makes sense to me.

Sunday 10 March 2024

A so far unidentified object in GEO near PAN and Eutelsat Hot Bird 13B [UPDATED]

PAN on March 4, 2024 (click image to enlarge)
UNID near PAN on March 8, 2024 (click image to enlarge)

In the evening of March 8 I did some observations to check upon the drifting PAN/NEMESIS-1 satellite. To my surprise, there was another object there that is not in the current catalogue (as of 10 March 2024). It wasn't there yet when I imaged the area 4 days earlier, in the evening of March 4, as can be seen by comparing the two images above.

Most likely this UNID is some commercial geosynchronous satellite that has been relocated without the 18th STS having caught that move yet. But it could also be something new. For now, it remains unidentified.

The UNID is located at about 33.8 E longitude. A very provisional elset:

UNID ML080324
1 99999U 24000X   24068.68698391 0.00000000  00000-0  00000-0 0    03
2 99999   0.0001  87.9800 0002372 229.7255 130.2564  1.00270000    07

The object could perhaps be the newly launched Chinese satellite WHG-01 (2024-040A). It was launched from Xichang a week ago, on 29 February 2024. Currently (March 11, 2024), only an 8-day old GTO elset is available for the object. That elset combined with the elset for the UNID above suggests that the satellite could have been inserted into GEO at 33.8 E on March 6 near 11 UTC.

Over the half hour arc that I imaged it on March 8, the UNID remained stationary. 

PAN/NEMESIS-1 is meanwhile slowly drifting west (the drift can be seen in the images above too, by comparing the distance of PAN/NEMESIS-1 to EUTELSAT HOT BIRD B13), as it has been doing for quite a while now. On 2024 March 8 it was near longitude 33.45 E. It is currently drifting at a rate of approximately -0.03 degrees per day.


PAN longitude of subsatellite point over time (click diagram to enlarge)

NOTE: an initial mix-up of the names of two recently launched Chinese GEO sats was corrected.


UPDATE 14 March 2024:

Space-Track, since yesterday (first non-GTO TLE has epoch 24073.71736125 = 13 March 2024 17:13 UTC), finally also places an object  in this position, catalogue nr 59069, COSPAR 2024-040A. Provisionally named "Object A", but the Cospar code indicates this would indeed be the Chinese satellite WHG-01.

The ISS EP9 battery pack observed on its last revolution before reentry

ISS EP9 battery imaged on 8 March 2024 18:17 UTC (click image to enlarge)

On 11 January 2021, a 2.6-tons car-sized container with old NiH batteries was detached from the International Space Station using the Canadarm2 robotic arm, and released into space. The object, called "ISS DEB (EP BATERRY)" by CSpOC, catalogue number47853, COSPAR 1998-067RZ, had since been slowly coming down for an uncontrolled reentry.

This reentry happened on 8 March 2024, at 19:29 +- 1 m UTC according to CSpOC, near 22 N, 85.5 W, over Yucatan and the western Caribean (the +-1 minute time uncertainty indicates that this is likely based on a SBIRS satellite detection of the reentry fireball).

Earlier similar packs of discarded NiH batteries were taken onboard visiting HTV supply spacecraft, to return and burn up in a controlled reentry with the HTV. For this last pallet, no HTV was available anymore, hence why it was unceremoniously tossed into space for a natural, uncontrolled reentry.


Canadarm2 releasing the container with NiH batteries into space (image: NASA)

In Germany, for some odd reason the news of the imminent reentry lead to a minor scare, with the German government issuing an alert through their cellphone civilian alert system, as the object would briefly pass over Germany within the (at that time almost a day wide!) reentry uncertainty window.

This alert was unnecessary in my opinion: yes, this was not a small object, and more solid than a rocket stage, but still, objects this size and mass and even bigger reenter several times a month - this was not an unusually large piece of space debris reentering. The very weekend following on this reentry for example, a 5-tons Chinese rocket stage, i.e. twice as heavy, would have an uncontrolled reentry as well. 

Chances of the pallet with discarded batteries coming down over Germany were less than 1%, and even if it would have done so, it would break up into much smaller pieces during reentry, and most of these would burn up in the atmosphere. Some pieces might survive and reach Earth surface, as with any reentry of a somewhat larger object, but the hazard is relatively small and is not of catastrophic proportions. Using the civilian alert system for catastrophies to issue alerts was panic-football, in my opinion, and it unnecessarily spread fear

Maybe it was meant to avoid panic in case of a reentry - with a spectacular light show in the sky and possible sonic booms - over Germany: but this alert reached the opposite I feel, creating unrest rather than avoiding it.

On its last orbit, slightly over an hour before reentry, I imaged the object passing over Leiden, the Netherlands around 18:17 UTC (March 8: 19:17 local time), as can be seen in the image above. This was in early twilight.

The object was moving very fast, zipping across the blue twilight sky, and bright: at magntiude -1 to -2 brighter than the brightest stars in the sky. I had no trouble seeing it naked eye. The image in top of this post is a 1/25th second exposure showing it passing through the constellation Auriga, almost right overhead (the bright twilight sky combined with a fast wide angle lensnecessitated a short exposure time).

A day earlier, on March 7th when all the anxiety in Germany erupted, I filmed it under terrible observing conditions (clouds came in just as the object was about to pass), where it was bright enough to shine through the clouds:

Tuesday 27 February 2024

A perigee-raising manoeuvre by the North Korean satellite Malligyong-1

Kim Jong Un inspecting a Malligyong satellite under construction in 2023. image: KCNA

On 21 November 2023 (see this earlier blogpost), after two failed earlier attempts, North Korea launched its first military reconnaissance satellite, Malligyong-1 (2023-179A), using its new Chollima-1 rocket. 

Like two civilian predecessors (KMS 3-2 in 2012 and KMS-4 in 2016), it did indeed reach orbit - an initialy 512 x 493 km, 97.43 degree inclined Sun-Synchonous orbit. But: although North Korea in the days and weeks after launch claimed the satellite took images of various US and South Korean Naval bases and  other important locations (such as the White House), it was not clear whether the satellite was really functional

North Korea never made any purported imagery taken by the satellite public, and independent radio trackers never detected any signals from the satellite.

But now we can definitely say the satellite is alive, On February 19, 2024, it initiated the first of a number of successive perigee raising manoeuvers that stepwise brought perigee (the lowest point in its orbit) up from 488 km to 497 km. It can be seen as the stepped "jump" in the red line in the diagram below, which maps the evolution of the apogee and perigee height of the orbit since launch:

click diagram to enlarge


The orbit raise appears to have been performed stepwise, in five increments, starting on February 19/20 and completed by February 24. The net effect was not only a perigee raise, but also a more circular orbit (currently 508 x 497 km).

click diagram to enlarge


The manoeuvre proves that Malligyong-1 is not dead, and that North-Korea has control over the satellite - something that was disputed.

South Korea's Defense Minister Shin Won-sik, commenting on the North Korean satellite, just this week remarked that it: "is currently in orbit. But it is not showing any signs of performing tasks or engaging in reconnaissance activities". Thus suggesting the satellite is not working.

That remark didn't age well: while we indeed currently can not be sure whether the satellite does successfully take imagery, it at least performs orbital manoeuvres, so in that sense it is functional. And to do such manoeuvers, you need to have the satellite under control, including attitude control.

The orbit raising manoeuver comes a bit as a surprise, as the presence of an onboard propulsion system is unexpected. The previous two North Korean satellites never manoeuvered. That Malligyong-1 has means of propulsion, was not something I and many other analysts expected.

Having the capacity to raise the satellite's orbit is a big deal. It means that North Korea, as long as there is fuel left in the satellite, can prolong the satellite's orbital lifetime, by raising its orbit when it gets too low due to natural orbital decay: thus delaying reentry into the atmosphere.

The orbit raise comes at a moment that some western observers expect that North Korea will launch another satellite soon.

Wednesday 21 February 2024

January UK Trident-II D5 SLBM test failed

It probably generated a lot of Stiff Upper Lip and an "Ow well, that is regrettable Old Boy...." from the UK Defense Secretary and the UK Royal Navy Commander that were on scene to witness the test.

For British media (e.g. The Sun here and the BBC here) report that the 30 January Trident-II D5 SLBM test launch from the British Royal Navy submarine HMS Vanguard, on which I wrote earlier here, failed.

From the description of the failure by The Sun, the suggestion is that the first stage failed to ignite after ejection of the missile from the submarine. As a result, it fell back into sea close to the submarine.

A previous British Royal Navy Trident test launch, in 2016, failed as well when the missile veered into the wrong direction after launch and had to be destroyed in flight.

In general, the Trident-II D5 is a reliable missile. The US Navy test-fires Trident SLBM's frequently, and most of their tests reportedly were successful. It just seems the British have bad luck lately.

UPDATE:  Statement by the UK Ministry of Defense to UK Parliament on the matter.

Friday 16 February 2024

Nukes in Space?

ionospheric glow caused by Starfish Prime, a 1962 nuclear detonation in Space (image: Wikimedia)

It sounds a bit like the fictituous Goldeneye satellite from the 1995 Bond movie of that same name: a secret Russian weapon in space waiting to unleash doom.

The past few days the media have been abuzz about a purported Russian Space Weapon, either nuclear or not, either deployed or not. 

The initial source was US Congressman Michael R. Turner, chairman of the House Intelligence Committee, who in an unprecedented public letter to House members said he had concerns about a "serious national security threath", urging President Biden to declassify the information. Subsequently, various US news sources quoted various of the proverbial "anonymous sources", with often conflicting information about the nature of the threath, but all indicating some kind of Russian space weapon.

What kind of weapon exactly, is unclear, although it seems to be an Anti-Satellite weapon of some sorts (see below). What caught the attention is that the 'anonymous sources' seemed to indicate something nuclear: either a nuclear weapon in space, or a nuclear powered satellite. Whether this is correct or not or just paranoia, is unclear at the moment.

A spokesman of the US White House National Security Council, ret. Admiral John Kirby, in reply briefed the press but with little pertinent extra information, apart from stating that he could confirm that "it is related to an anti-satellite capability that Russia is developing":


He also made it clear that it is "not an active capability that has been deployed". In other words, there is currently not a weapon already lurking in space. And, he did clarify that it does not concern something targetting objects on the Earth surface.

It should also be noted that Kirby did not unambiguously mention (see below for what I exactly mean with that) that the 'capability' in question is nuclear, so this remains an unverifiable rumour from anonymous sources that might or might not be wrong. 

However, at 26:45 into the press conference, he does confirm that this Russian capacity is 'space-based': i.e. not a kinetic interceptor fired from earth, but a weapon to be deployed on-orbit; and he states, interestingly enough, that it "would be a violation of the Outer Space Treaty"

The latter is an interesting phrasing and could perhaps be taken to indicate something nuclear after all (but: see what is following), as the 1967 OST, to which Russia is a signatory State, in article IV of the Treaty prohibits the deployment of Weapons of Mass Destruction (and very specifically nuclear weapons) in space. 

On the other hand, the remark of  "violating the OST" might simply refer to Article VII, that holds parties to the OST responsible for any damage they inflict in space on satellites from other Nations; or Article IX that says that signatory States should avoid "harmfull contamination" of Space (such as the creation of harmfull space debris from an ASAT test). 

So it all remains ambiguous here and the 'capability' in question might not have any nuclear aspects (e.g. being nuclear-powered, which is not a violation of the OST, or a nuclear weapon, which is) at all, depending on how you interpret the wording of Kirby's statements. There is a lot of interpretational wiggle room here.

That Russia is pursuing anti-satellite (ASAT) capabilities is nothing new. In November 2021, they conducted a much-criticized kinetic ASAT test targeting and destroying their Kosmos 1408 satellite (see my earlier posts here and more elaborate here) that created orbital debris in Low Earth Orbit and made astronauts and kosmonauts onboard the ISS briefly take shelter in their Soyuz capsule. 

The new element of the capability that is now the subject of all this discussion, appears to be that it is to be space-based. But even that is not really new. Over the past years, there has been much concern about Russian proximity operations in space (Russian satellites approaching other satellites, either Russian or from other countries, very closely: or ejecting sub-satellites/apparent projectiles).

In 1987, the former Soviet Union attempted to launch a prototype space-based laser weapon Polyus/Skif (that launch failed). Maybe they are up to something like that again. And for a long time, it is said that Russia is working on a nuclear-powered electronic warfare satellite, Ekipazh.

proximity operation of the Russian LUCH/OLYMP 2 SIGINT satellite close to a commercial geostationary satellite, as seen in this image I made from Leiden on 20 Sept 2023


In general, ASAT weapons are usually not weapons that are smart to use, as they do more harm than good.

Both kinetic ASAT weapons (that destroy satellites and in that process generate a lot of potentially harmful orbital debris) and nuclear detonations in space for use as ASAT, are indisciminate weapons that do not only harm your target, but potentially also harm other satellites, including your own satellites and those of Nations not part of the conflict in question. 

This is not the case for every ASAT weapon though. For example, a weapon that would attach to a target satellite and mechanically or electronically sabotage it, would be less harmfull to other satellites, although it does produce at least one piece of space debris, a dead satellite.

[clarification added 17:30 UTC on 16 Feb 2024:
The paragraphs below discuss a nuclear EMP device in space. There is however another option, that of a nuclear powered but in itself not nuclear ASAT weapon, where a nuclear reactor provides the power source for another type of weapon, e.g. a very powerful laser
(see the mention of Polyus above) or radio jammer (see the mention of Ekipazh above). This was one of the SDI concepts back in the 1980'ies. Nuclear powered satellites in itself are not new: both the Soviet Union and the USA have used them in the past, for example the Soviet RORSAT's that used nuclear power to power a powerful radar. Nuclear powered satellites do not violate the OST.]

As the nuclear spectre was raised by the 'anonymous sources' (which could have political agendas to do so), let's discuss this for a moment. Before the OST came into effect, Nuclear weapons tests have actually been conducted in space. And the results were very concerning.

The most well known of these is the US Starfish Prime test of 1962, part of Operation Fishbowl, where a 1.4 megaton nuclear bomb launched by a Thor rocket was detonated in Space at 400 km altitude. But there were also three smaller, earlier, low yield US tests in 1958 as part of Operation Argus.

Starfish Prime surpassed all expectations, leading to a halt in this kind of testing. Detonated at 400 km altitude over Johnston atoll, the Electro-Magnetic Pulse (EMP) created by the nuclear detonation actually inflicted damage at ground level on Hawaii, 1450 km away, where it knocked out some streetlights and parts of the telephony network.

(Note that in our modern world, where lots of electronics work based on microprocessors which are very vulnerable to EMP, we are much more vulnerable to such effects than the world was in 1962).

1962 Starfish Prime detonation flash as seen from Honolulu (image; Wikimedia)  

ionospheric glow caused by charged particles from the 1962 Starfish Prime detonation (image: Wikimedia)


In addition, charged particles generated by the detonation and carried along the Earth's magnetic field damaged several satellites

Of the 25 satellites in earth orbit on that date (this was the early space age), nine were damaged and eventually failed early as a result of this test. It concerned seven US satellites, one UK satellite, and one Russian satellite.

The damage is done by beta particles and electrons generated by the detonation, which spread through the earths magnetic field and ionosphere (which includes a considerable part of Low Earth Orbit), and damage electronic components in satellites. Some of these particles can linger on in the ionosphere for quite a long time (months).

In addition, the charged particles released into the ionosphere by the test generated Aurora-like effects on low latitudes, generating conditions that speed up the orbital decay of satellites.

In other words: using a nuclear bomb as an ASAT weapon in space, is not a very sensible approach. I would be surprised if Russia would use such a weapon, as its side-effects potentially could criple its own space assets too.

[note added 18 Feb 2024:] And it might actually do less harm to western military satellites (the ones Russia would want to target) than to civilian satellites, as several critical military space platforms have actually been hardened against EMP.

update 18 Feb 2024: CNN has published a story that is getting some traction, where it appears to be claimed that the 'weapon' in question is in fact an EMP device. 

But it is again based on anonymous sources: and anonymous sources so far have been contradictory in this, and there could be political agendas behind such 'anonymous' statements. Only a few years ago, a group of hawks in US politics were trying to push the alarmistic story that North Korea was developing (and even would already have tested, a claim which is certainly bogus) space-based EMP weapons (a dark interpretation of North Korea's KMS satellites). Their agenda was that they were advocating for a preemptive strike on North Korea.

(note: added a few sentences on the 1980'ies Soviet space-based laser weapon Polyus/Skif and the Ekipazh concept a few hours after the initial version of this post appeared).

Wednesday 14 February 2024

USSF-124, launching the Hypersonic and Ballistic Tracking Space Sensor

click map to enlarge

If all goes well, SpaceX will launch USSF-124 for the US Space Force on 14 February 2024, using a Falcon 9 rocket launching from Cape Canaveral launch pad 40. The launch window opens at 22:30 UTC and runs untill 3:00 UTC.

USSF-124 launches two classified payloads, one built by Northrop-Grumman and the other by L3 Harris, for the Missile Defense Agency. The two satellites are part of their Hypersonic and Ballistic Tracking Space Sensor (HBTSS). 

In addition, the final four of SDA's SDA Tranche 0 satellites are part of this launch too.

The Navigational Warnings related to this launch (see map above) point to launch into a ~38.5 degree inclined Low Earth Orbit. The orbital altitude will likely be around 600 km.

The upper stage of the Falcon 9 will deorbit after 1.5 revolutions, over the Indian Ocean east of Madagascar, some 2 hours and 20 minutes after launch.

The Navigational Warnings are plotted in the map in top of this post. These are the Navigational Warning texts:

090947Z FEB 24
NAVAREA IV 146/24(11,26).
   142230Z TO 150300Z FEB, ALTERNATE
   2230Z TO 0230Z DAILY 15 THRU 20 FEB
   A. 28-38.28N 080-37.18W, 28-45.00N 080-18.00W,
      28-43.00N 080-09.00W, 28-36.00N 080-07.00W,
      28-28.00N 080-20.00W, 28-27.11N 080-31.61W.
   B. 29-58.00N 077-39.00W, 30-42.00N 076-26.00W,
      31-00.00N 075-43.00W, 30-34.00N 075-28.00W,
      30-21.00N 075-53.00W, 29-53.00N 077-35.00W.
2. CANCEL THIS MSG 210330Z FEB 24.//

081626Z FEB 24
HYDROPAC 483/24(61).
DNC 02, DNC 03.
   0056Z TO 0519Z DAILY 15 THRU 21 FEB
   36-40.00S 078-41.00E, 34-50.00S 079-51.00E,
   26-27.00S 060-32.00E, 28-17.00S 059-28.00E.
2. CANCEL THIS MSG 210619Z FEB 24.

Tuesday 13 February 2024

Imaging the X-37B robotic spaceplane mission OTV 7

OTV 7 imaged from Leiden at 12 Feb 2024. Click image to enlarge

In my previous post, I wrote about the first on-orbit detections, by Tomi Simola, of the US Space Force's X-37B space plane mission OTV 7, and how it is in an orbit that is certainly unusual for a space plane.

Yesterday (February 12, 2024) I finally had a clear sky, and an almost near-zenith pass of OTV 7 in the early evening just after twilight. So I could finally image it too

Using the ZWO ASI 6200MM PRO with a 1.2/85 mm lens, OTV 7 showed up well in the imagery, as a reasonably bright object that was not difficult to detect. Above is one of the images, a 10 second exposure near 19:06 UTC while OTV 7 was over Europe at ~6700 km altitude, descending towards perigee.

The orbit is now a bit better constrained, and about  38600 x 300 km at 59.15 degree inclination. Perigee is currently over the equatorial region. The image below shows the orbit, and the orbital position of OTV 7 around the time I imaged it:

click image to enlarge

OTV 7 was several minutes early on one day old elements, meaning it appears to be actively manoeuvering. This fits an X-37B, the previous OTV missions (all to LEO) were also frequently manoeuvering. 

It is possible that the spacecraft is using a continuous thrust ion engine.

In the current Highly Elliptical Orbit (HEO), the orbital velocity at perigee is close to 10.2 km/s, which is 2.4 km/s more than in a Low Earth Orbit (previous X-37B missions all went to Low Earth Orbit). To eventually land the spaceplane, the orbit likely will be circularized first, by lowering apogee drastically, perhaps with the help of aerobraking in perigee, before doing a deorbit and landing.

This is my current orbital fit, which is still up for improvement, based on observations by Tomi Simola, Eelke Visser, Scott Tilley and me:

1 58666U 23210A   24044.12782730 0.00000000  00000-0  00000+0 0    05
2 58666  59.1696   4.0545 7416334 167.8228 233.0020  2.09261279    07

Saturday 10 February 2024

X-37B OTV 7 has been found in HEO!


OTV 7 discovery image by Tomi Simola, Finland  ((c) Tomi Simola, used with permission)

On 29 December 2023 at 1:17 UTC, after several delays, SpaceX launched a Falcon Heavy for the US Space Force with OTV 7, the seventh X-37B Spaceplane mission. Now its payload has been found!

OTV 7 was the subject of much speculation. The use of a Falcon Heavy, and the locations and time windows of related rocket stage splash-down and reentry zones, as well as statements by the US Space Force, indicated it might go into a different, higher altitude orbit than the previous six missions. On this blog, I speculated about a ~74-degree inclined Highly Elliptical Orbit (HEO).

Thanks to the dedicated efforts of Tomi Simola from Finland, OTV 7 has been found on-orbit this week. It is indeed in a HEO orbit, but inclined by 59.1 degrees, not 74 degrees.

Tomi performed a dedicated plane scan using a fixed staring camera. On the night of 7-8 February, he finally nabbed the elusive payload (see the discovery image above), while it was at ~3400 km altitude descending towards perigee. He used a WATEC 902H2 Ultimate camera with a 1.2/50 mm lens and 10 seconds integration.

Subsequent observations show that OTV-7 is in a 38840 x 323 km, 59.1 degree inclined Highly Elliptical Orbit. Perigee is just North of the equatorial region (currently clearly North of it near latitude 30 N, but short after launch it was at a lower latitude near 15 N).

(a Highly Elliptical Orbit (HEO) is an orbit with a low perigee - generally at a few hundred km altitude -  and distant apogee, at 35 000 km altitude or more. As a result, the shape of the orbit is highly elliptical (highly elongated). An object in HEO typically makes two orbital revolutions a day. Due to the shape of its orbit, it spents most of its time in the higher parts of the orbit and a relatively small amount of time near perigee. When apogee is over high latitudes, as is usually the case for these orbits, this allows a long dwell-time over these latitudes with view of a very large area (a full hemisphere when in apogee). HEO orbits are hence the polar equivalents of a GeoSynchronous Orbit (GEO) and often used for communications relay or long-term monitoring of areas. They are a favoured orbit for Communications, SIGINT and Infra-Red missile launch monitoring. The OTV 7 HEO is unusual in that perigee is not over the southern hemisphere).


orbit of X-37B OTV-7 as of 10 Feb 2024. Click to enlarge

The observed orbital plane of the object matches well with a launch from Cape Canaveral on 29 December 1:07 UTC. Together with the fact that the orbit is quite unusual for a HEO object with it's Northern hemishere perigee location, an identification with OTV 7 is very likely.

Propagating the orbit backwards, the suggestion is that, after initial launch into a 51.5 degree inclined low coasting orbit, it was pushed into HEO by a manoeuvre when crossing the descending node, about half a revolution after launch. It subsequently probably manoeuvered a couple of times, adjusting apogee and perhaps also inclination. 

The upper stage probably did a second manoeuvre after payload separation, changing its inclination to 74 degrees as suggested by the shape, orientation and location of the deorbit area from the Navigational Warnings related to the launch.

click map to enlarge

The map above plots the current orbit of OTV 7 propagated back to the day of launch, as well as the estimated initial low coasting orbit.

As can be seen, the OTV 7 orbit after one revolution actually does cross over the deorbit area from the Navigational Warnings: but in an oblique way that does not seem to match the orientation of the area. This is why I believe that the upper stage after payload separation was boosted into a higher inclined orbit. Perhaps as a collision avoidance manoeuvre (but the implied magnitude of the inclination change, 15 degrees, is rather large), perhaps - but that is pure speculation - it might have delivered a second payload to a higher inclination.

Because their orbital inclinations are about half a degree apart, I did look into a possible relation with another odd object launched into an odd orbit recently: USA 310. Their orbits are quite dissimilar though: USA 310 is in a circular MEO orbit inclined by 58.5 degrees, not a HEO orbit. I do note that their orbital planes, even though quite dissimilar, are 90 degrees apart. But most likely, that is coincidence.

click to enlarge

It will be interesting to follow OTV 7, and see whether it changes orbital altitude as often as the missions to LEO did (see this post from a few years ago).

A re-usable space-plane in HEO: who had that in the cards for 2024....?!

Let's see if they can get it back at some point.