Thursday, 17 June 2021

An intriguing apparent Missile Defense (?) test from Kodiak and Kwajalein


click map to enlarge

A Navigational Warning issued on June 16 seems to point to a possible Missile Defense test on June 21, with missile launches from Kodiak Island in Alaska (the Pacific Space Port Complex) and the Kwajalein Test Range in the Marshall islands.

Below is the text of the Navigational Warning in question, NAVAREA XII 271/21, defining four areas A to D. I have mapped the areas in the map in top of this post, with one of several possible interpretations (in this interpretation, an interceptor is launched from Kwajalein to intercept an ICBM launched from Kodiak. The flight distance involved for the interceptor in this scenario does not sit well with me though).

160922Z JUN 21
NAVAREA XII 271/21(16,19,81).
   210830Z TO 211430Z JUN, ALTERNATE 
   0830Z TO 1430Z DAILY 22 THRU 25 JUN 
   A. 57-29N 152-20W, 57-20N 152-11W, 
      56-39N 153-28W, 56-41N 153-33W,
      57-11N 152-47W, 57-16N 152-43W,
      57-19N 152-38W, 57-21N 152-38W,
   B. 51-08N 160-22W, 50-58N 159-50W,
      51-01N 159-26W, 51-17N 158-58W,
      51-42N 158-35W, 52-29N 158-16W,
      52-32N 158-24W, 51-51N 159-35W,
      51-23N 160-14W.
   C. 33-50N 171-41W, 33-44N 171-27W,
      36-52N 169-25W, 38-40N 168-15W,
      39-58N 167-47W, 40-02N 167-59W,
      39-15N 168-39W, 38-27N 169-18W,
      37-05N 170-02W.
   D. 12-45N 172-48E, 08-11N 166-38E, 
      08-56N 166-01E, 13-34N 172-11E.
2. CANCEL THIS MSG 251530Z JUN 21.

There is an additional Navigational Warning, NAVAREA XII 270/21, defining several areas west of Hawaii for several dates around the possible test, in the general area where the launch trajectories from Kodiak and Kwajalein seem to meet. One of the dates issued (nr 2, highlighted in red) has a time window that, while not similar, does overlap with the time window of warning NAVAREA XII 271/21:

150910Z JUN 21
NAVAREA XII 270/21(19).
   22-42.0N 172-13.0W, 22-28.2N 171-01.3W, 
   21-08.4N 171-20.8W, 21-22.0N 172-35.0W.
   A. 30-37.0N 169-02.0W, 30-13.0N 167-20.0W, 
      29-07.0N 167-41.0W, 29-24.0N 169-04.0W.
   B. 24-05.0N 171-50.0W, 23-50.7N 170-36.7W, 
      22-28.2N 171-01.3W, 22-42.1N 172-13.0W.
   C. 23-06.0N 178-55.0W, 23-06.0N 175-15.0W, 
      21-40.0N 175-15.0W, 21-40.0N 178-55.0W.
   D. 22-00.0N 167-58.0W, 22-00.0N 166-36.0W, 
      20-19.0N 166-36.0W, 20-19.0N 167-58.0W.
   A. 29-10.0N 169-54.0W, 28-25.0N 167-54.0W, 
      27-28.0N 168-11.0W, 28-06.0N 170-23.0W.
   B. 23-50.7N 170-36.7W, 23-37.0N 169-28.0W, 
      22-14.8N 169-48.4W, 22-28.2N 171-01.3W.
   C. 23-06.0N 178-55.0W, 23-06.0N 175-15.0W, 
      21-40.0N 175-15.0W, 21-40.0N 178-55.0W.
   D. 22-00.0N 167-58.0W, 22-00.0N 166-36.0W, 
      20-19.0N 166-36.0W, 20-19.0N 167-58.0W.
   A. 28-06.0N 170-12.0W, 27-28.0N 168-11.0W, 
      26-30.0N 168-27.0W, 27-00.0N 170-30.0W.
   B. 22-28.2N 171-01.3W, 22-14.8N 169-48.4W, 
      20-55.0N 170-08.0W, 21-08.4N 171-20.8W.
   C. 20-19.0N 170-20.0W, 20-29.0N 168-01.0W, 
      18-01.0N 168-01.0W, 18-01.0N 170-20.0W.
   20-19.0N 170-20.0W, 20-29.0N 168-01.0W, 
   18-01.0N 168-01.0W, 18-01.0N 170-20.0W.
6. CANCEL THIS MSG 241100Z JUN 21.

It is not clear whether these Navigational Warnings really are related to the Navigational Warnings from NAVAREA XII 271/21. They might be, or might not be. If they are, this might be one of several possible interpretations, pointing to a multiple target intercept where both a missile fired from Kodiak and a missile fired from Kwajalein are to be intercepted:

click map to enlarge

When I presented the evidence for a possible 21 June Missile Defense test on twitter, there were some suggestions that this might be the planned test FTT-21

However, what is known of that planned FTT-21 test suggests the target(s) for that test should be SRBM, i.e. a missile with a range of no more than 1000 km. Which is at odds with what seems to be indicated by the Navigational Warnings, with the missile fired from Kodiak  apparently flying at least 6000 km (assuming areas A to C, blue in the map, define the trajectory of one and the same missile) and the Kwajalein missile at least 1800 km if it is to intercept the Kodiak missile or if it is to be intercepted from area B of the second Navigational Warning (the red area A in the map above). That would be ICBM and IRBM targets, not SRBM targets.

In other words: it is not clear what is going on here, which makes this an interesting issue.

Monday, 14 June 2021

USA 224 has manoeuvered

During the night of June 12-13, I was doing a periodic checkup on the KH-11 Advanced Enhanced CRYSTAL satellites  USA 224 (2011-002A) and USA 314 (2021-032A) that occupy the KH-11 primary East plane. This because I expect USA 224 to manoeuvre to the secondary East plane at some point this summer, now USA 314 has recently been launched into its orbital plane as a replacement (see discussion in my earlier blogpost here).

USA 224 did not appear at the nominal time on June 13 but some 2m 20s late, indicating a manoeuvre.

Observations by David Brierley and me on June 12/13 and 13/14 have established this preliminary post-manoeuvre orbit:

USA 224                                                  255 x 998 km
1 37348U 11002A   21165.00715133 0.00014912  00000-0  12302-3 0    05
2 37348  97.8892 276.6083 0530502 157.6427 204.8870 14.81006602    06

It is clear that this is not the big plane-changing manoeuver expected, but a small regular orbit upkeeping manoeuvre: apogee was raised by some 10 km. 

From the pre- and post-manoeuvre orbit,  I calculate that the manoeuvre took place on Thursday June 10 near 14:14 UT, over the Atlantic, during crossing through the descending node and perigee. 

As usual, the manoeuvre happened while perigee was situated over the equator (when the Mean Anomaly is near 180 degrees, this is always a moment to watch out for manoeuvres). This allows to make adjustments in both orbital altitude and inclination in the same burn, with a minimum expense of fuel.

Observing TacRL-2/Odyssey and it's Pegasus upper stage


I observed the Space Force's new Odyssey/TacRL-2 satellite last light, some 15.5 hours after it's airborne launch on a Pegasus-XL rocket (see previous blogpost). The Pegasus upper stage of the launch was observed as well, close to the payload.

They can both be seen in the video above, shot with a WATEC 902H2 Supreme and Samyang 1.4/85 mm lens. Which of the two objects is which is unclear at the moment: the identities have switched between successive orbit updates.

The bright object moving at a tangent at 23:43:23 UT is a Starlink satellite. While observing over the past few nights, the by now ubiquitous and still growing number of Starlink satellites was very apparent. There isn't a minute that one doesn't pass through the field of view. They have a large range in brightness.

Saturday, 12 June 2021

NROL-111 and TacRL-2: two upcoming classified launches [UPDATED]

click map to enlarge


Two classified launches are slated for the second week of June. One is the launch of TacRL-2, on 13 June at 8:11 UT. The other is NROL-111 on June 15 between 10:00 and 15:30 UT [edit: a potential launch time of 11:00 UT has now been announced]. Both are launched by Northrop Grumman, on behalf of respectively the Space Force and the NRO.



TacRL-2 is described as a "Space Domain Awareness" technology demonstration satellite that is part of the "Tactically Responsive Launch Program" (hence "TacRL") of the US Space Force. The satellite was reportedly developed in less than a year time.

It will be an airborne launch, on one of two remaining Northrop Grumman Pegasus-XL rockets carried by a Lockheed L1011 Tristar aircraft. The launch will be over the Pacific, near California.

The Navigational Warnings issued point to launch into a polar Low Earth Orbit with orbital inclination near 96 to 98 degrees. Below are the Navigational Warnings, which I have also mapped in the map above:

090844Z JUN 21
NAVAREA XII 257/21(18,83).
   A. 35-19N 123-44W, 35-13N 122-58W, 
      31-11N 124-05W, 31-16N 124-30W.
   B. 29-34N 125-03W, 29-28N 124-29W, 
      27-32N 124-53W, 27-38N 125-26W.
   C. 20-19N 127-23W, 20-02N 125-41W, 
      15-26N 126-30W, 15-43N 128-11W.
   D. 01-20N 131-46W, 00-35N 127-20W, 
      01-52S 127-44W, 01-06S 132-11W.
2. CANCEL THIS MSG 140955Z JUN 21.
080051Z JUN 21
HYDROPAC 1691/21(83).
DNC 06, DNC 13.
   130840Z JUN AND 140809Z TO 140840Z JUN
   01-20N 131-46W, 00-35N 127-20W,
   01-52S 127-44W, 01-06S 132-11W,
   01-20N 131-46W.
2. CANCEL THIS MSG 140940Z JUN 21.

In my initial assessment I suggested a 98-degree sun-synchronous orbit as a possibility [EDIT: and it turns out that I was right in that: the payload has been catalogued in a 97.48 degree inclined orbit, catalogue nr 48844]; but I have since revised that assessment based on sensible comments by Bob Christy. His ~96-degree inclined orbital suggestion indeed fits the hazard areas well. Yet, my initial suggestion of a sun-synchronous orbit cannot be totally discounted either [EDIT: see earlier remark: it in fact *is* in a sun-synchronous orbit near ~98 degree inclination, and I am therefore very happy that I included this statement...]. In the map in top of this post, I have plotted the 96-degree inclined option.

UPDATE (13 Jun 11:20 UT): TacRL-2 launched successfully. According to the Space Force, the satellite is named Odyssey.

UPDATE (13 Jun 21:00 UT): Odyssey/TacRL-2 has been catalogued by Space-Track under catalogue nr. 48844, in a 405 x 452 km, 97.48 degree inclined orbit. The orbit is, against expectations, not classified.


Two days after TacRL-2, Northrop Grumman will launch another mission, NROL-111, this time for the NRO. The launch will be on June 15,with a launch window between 10:00 and 15:30 UT. [EDIT: in a tweet, the NRO has now announced 11:00 UT as the launch time)

It concerns the launch of three unspecified small payloads on a Minotaur I rocket. The launch will be from Wallops Pad 0B (Press Kit here). The Navigational Warnings (see below) point to launch into a ~50-degree inclined Low Earth Orbit:

110950Z JUN 21
   151000Z TO 151530Z JUN, ALTERNATE 
   1000Z TO 1530Z DAILY 16 THRU 21 JUN 
   A. 37-57-27N 075-27-32W, 37-38-42N 074-52-00W,
      37-24-46N 075-06-02W, 37-41-36N 075-37-02W.
   B. 36-46-37N 074-55-59W, 37-18-40N 074-06-36W, 
      37-01-44N 073-19-30W, 36-27-47N 072-14-49W, 
      35-59-28N 072-14-38W, 35-30-18N 073-03-54W, 
      35-39-00N 074-02-06W.
   C. 30-10-19N 069-45-00W, 33-31-19N 067-19-52W, 
      30-57-14N 064-49-52W, 29-31-30N 067-11-42W. 
   D. 07-00-00N 048-09-43W, 10-19-01N 044-06-50W, 
      06-14-02N 038-38-13W, 01-44-13N 043-46-37W.
2. CANCEL THIS MSG 211630Z JUN 21.


I have plotted the Navigational Warnings in the map below (click to enlarge):

click map to enlarge


We can only speculate about the possible functions of the NROL-111 payloads, and the same is true for TacRL-2 ("Space Domain Awareness" broadly suggests the latter is keeping an eye on other satellites). Both missions appear to be experimental. With regard to NROL-111, I just note that orbital inclinations near 50 degrees lately have become very popular with the NRO for some reason.

Sunday, 23 May 2021

From what altitude does space debris drop vertically?

While gearing up for the CZ-5B reentry in the first week of May, an interesting exchange developed on Twitter between @SpaceTrackOrg, @DutchSpace and me, regarding the way space debris falls down in the last few tens of kilometers before hitting ground surface

It was triggered by the comment by @SpaceTrackOrg that the coordinates in their TIP messages typically refer to the object at 10 km altitude, not ground level:

As I pointed out in the Twitter thread, increasing drag acting on the fragments during reentry will not only make them start to ablate (and fragment), but will also slow them down, to a point where they finally have lost all initial forward momentum. From that point onwards they drop straight down.

During that tweet exchange, I decided to prove my point to initial disbelievers with a General Missions Analysis Tool (GMAT) model. I constructed an orbit for a hypothetical satellite about to reenter. I next ran this object through a GMAT model, modelling descent through the MSISE90 model atmosphere: initially for a 10 kg mass and 1 m2 drag surface, but later I ran the model for 5 kg and 50 kg masses too, capturing a range of area-to-mass ratio's. The initial speed was orbital (7.4 km/s) and the starting orbital altitude was 80 km, just below the tipping point between orbital and suborbital altitude (in this way, rapid reentry in the model was assured).

The movement in latitude and longitude from the model output was next converted to movement in meters at the earth surface (I did this in QGIS), i.e. horizontal displacement, yielding this diagram that maps the horizontal component of movement of each fragment against atmospheric altitude:

click diagram to enlarge

As can be seen, all three objects indeed reach a point where horizontal movement becomes essentially zero - they drop down vertically from a certain point. 

These points where the horizontal movement becomes zero are located at about 45 km altitude for a 5 kg object  (with a 1 m2 drag surface), about 35 km for a 10 kg object (with 1 m2 drag surface), and about 25 km for a 50 kg object  (with 1 m2 drag surface).

So our GMAT model demonstrates what I argued: from a certain point, well above 10 km atmospheric altitude, fragments from a reentry loose their forward momentum and basically start to drop down vertically, essentially a free fall.

But the reality is, of course, a bit different and more complex than this model suggests. Apart from atmospheric drag and gravity, there is another force that starts to act on these fragments once in the (upper) atmosphere, one that GMAT does not account for. The force in question is high altitude winds, which above 50 km altitude can be very strong.

So the reality is, that these high altitude winds at a certain point start to become the main force of horizontal displacement - fragments are litterally being blown away by these winds. As a result, the actual fall from the mentioned altitudes is not straigth down: falling fragments can be blown away laterally from the initial trajectory, or foward along the trajectory, and even be blown backwards along the initial trajectory, depending on the direction of the high altitude winds! The displacement, especially for fragments that are relatively large for their mass (space debris fragments usually are, as they usually are not solid), can be many kilometers.

This effect is well known to meteor astronomers, as it is a complicating factor in calculating where any meteorite fragments from a fireball might have landed. Like space debris, meteorites likewise are slowed down once descending through the atmosphere, and from ~25 to ~15 km altitude (their initial speed is faster than that of space debris and they are more dense, hence they penetrate deeper before losing their cosmic speed) they start the same kind of free fall, moving primarily under the effects of high altitude winds.

As an aside: I would love to see someone add the capability to import and effect high altitude wind profiles into GMAT, so this kind of displacement could be modelled in GMAT!

Note that, in interpreting the diagram above, one should realise that it maps horizontal displacement relative to altitude in the atmosphere. The modelled fragments do not end up in the same geographic location

For a given drag surface, low mass objects will come down earlier along the trajectory than heavier objects. This can be seen in the diagram below, which also shows you that the debris footprint of a reentry can easily be hundreds of kilometers long, something to keep in mind when looking at reentry coordinates in TIP messages:


click diagram to enlarge

It takes quite a while for these objects to come down through the lower layers of the atmosphere too, especially if they are large but lightweight:

click diagram to enlarge

The actual fall durations are heavily influenced by the area-to-mass-ratio. Relatively solid fragments (low area-to-mass) will come down faster, sheet-like or hollow objects (high area-to-mass) will come down slower. Surviving fragments will trickle down over tens of minutes. This is one reason why the time windows given for hazard areas during a controlled rocket stage reentry are usually an hour or so in duration.

From meteoric fireball studies, we know that as a rule of thumb, ablation (mass loss, i.e. burning up) of fragments stops once their speed is below ~3 km/s. Note that for low melting point materials like aluminium, the speed might actually be somewhat lower (meteorites are rock or iron with melting points at ~1100-1500 C, while aluminium has a melting point at ~660 C).

For the three modelled fragments (all modelled for a drag surface of 1 m2), the 5 kg fragment reaches this point at 77 km altitude; the 10 kg fragment at 73 km altitude; the 50 kg fragment at 61 km altitude. Note that the results will be different when modelling with the same masses but a different drag surface (for a smaller drag surface, the altitudes for a given mass will get lower, as they don't slow down as rapidly). Also note my earlier remark about materials with low melting point temperatures. But in general: anything that survives to below ~50 km in the atmosphere, will probably reach ground surface.

Thursday, 20 May 2021

The front group of Starlink V1.0 - L26

On May 15, yet another batch of SpaceX Starlink satellites was launched, and they are currently making evening and early night passes over Europe. Since launch, the resulting 'train' of satellites from the launch has split into two distinct groups passing a few minutes after each other.

The video above is from yesterday night (19 May 2021 ~23:17 UT) and shows the leading group, which is still quite tight. The trailing group (also captured but not shown in this video clip) is more dispersed. The video was shot with my DSLR: Canon EOS 80D + Samyang 1.4/85 mm lens.

A night earlier, I captured both the leading and trailing group with the WATEC 902H2 Supreme + FD 1.8/50 mm lens (see video below). They were naked eye during that pass.

Wednesday, 19 May 2021

SBIRS GEO 5 Centaur fuel blowout imaged from Australia

click to enlarge

On 18 May 2021 at 17:37 UT, the United Launch Alliance (ULA) successfully launched SBIRS GEO 5 for the US Space Force from Cape Canaveral, using an Atlas V rocket. SBIRS GEO 5 is an Early Warning satellite that detects missile launches (SBIRS = Space-Based Infra-Red System). It was placed in a geosynchronous orbit. Two other small rideshare payloads were also launched on this launch.

Looking at the mission profile, I realized that the fuel blowout of the Centaur upper stage from the launch would be visible from Australia and Indonesia. So I alerted the Seesat-list and also sent a private alert to Paul Camilleri, an observer in Australia who in the past has made spectacular imagery of such Centaur fuel blowout events.

Paul grabbed his camera and went out. And returned with spectacular imagery, which I show here with his kind permission. According to Paul, the blow-out cloud reached magnitude +3.

Paul made his imagery with a Nikon D3200 with an F2.0/85 mm lens. They are 5-second exposures (fixed tripod) at ISO 6400.

In the first image shown, taken 18:55 UT just before start of the blowout sequence, you can see both the Centaur upper stage and the SBIRS GEO 5 payload, which had separated from the Centaur some 40 minutes earlier. In the second image shown, taken 5 minutes later, you can see a V-shaped fuel cloud and a circular ring of blown-out fuel. In the other images, you see further venting, creating a bright V-shaped cloud that slowly dissipated over the next tens of minutes. Paul imaged it untill 19:40 UT.


Click images to enlarge


Paul was not the only one imaging the fuel blowout. Australian astronomer Robert McNaught also captured the event on his all sky camera (image used with permission):



The fuel blowout happened at about 12000 km altitude. The Centaur upper stage was over the eastern Indian Ocean, just northwest of the West Australian coast at that moment (see map below).

click map to enlarge

Fuel blow-outs are done to get rid of left-over rocket fuels in the rocket stage. Venting them into space reduces the risk that vapours from the left-over fuel might ignite (e.g. because of static electricity buildup in the rocket stage) and cause a debris-generating explosion.


Animated image sequence by Grahame Kelaher from Australia:


Animated image sequence by Tel Lekatsas, also from Australia:

A movie from the all-sky camera of the Edward Pigot Seismic Observatory, courtesy of Michael Andre Phillips in Australia is here (look at the right of the image in the gap in the trees)

Thursday, 6 May 2021

Reentry predictions for the Chinese CZ-5B rocket stage 2021-035B [UPDATED]


CSpOC/18th Space Control Squadron report that the CZ-5B rocket booster 2021-035B met a fiery end at 2:14 UT last night (May 9) over the Arabian peninsula and Indian Ocean. China reports reentry at 2:24 UT in the Indian Ocean near the Maldives

click map to enlarge

UPDATES 9 May 2021, 9:00 UT and 14:30 UT:

In the map above, I have plotted the approximate final trajectory (based on a SatEvo-evolved orbit propagated to reentry) and both the reentry locations reported by China (2:24 UT, 2.65 N, 72.64 E, in the Indian Ocean near the Maldives) and by CSpOC/18th Space Control Squadron (2:14 UT, 22.2 N 50 E, over the Arabian Peninsula).

Note how within minutes of the reentry, the rocket passed over the city of Riyahd in Saoudi-Arabia!

In looking at the plot, one should realize that a reentry is not an instantanious moment, but a process stretching over many minutes, where the object starts to break up and fragments burn up in the upper atmosphere. During this process, the object continues to move over a swat of trajectory that can be hundreds to a few thousands of kilometers long. It is very likely that this proces started over the Middle East or even over the Mediterranean already [edit: imagery from Jordan suggest that the object was still intact when passing over that location, but see a potential video from Oman below]. If fragments survived, they are scattered somewhere along the yellow line in the map, within the current uncertainties of the reentry location.

The video footage in the tweet below appears to show the (start of the) reentry, imaged from Oman, but is unverified for now:

I have tried, by fiddling with the area-to-mass ratio for the rocket in GMAT, to create a reentry trajectory that would match a splashdown in the Maldives around 2:24 UT, as reported by China. The closest I can get to the location reported by China is this result:

click map to enlarge

Of course, this is a simplified model (the proverbal "spherical cow in a vacuum") that does not take into account both mass loss from ablation and fragmentation over the reentry trajectory.

It however suggest that, if the time and location reported by China is right, the rocket stage would have been at an altitude of ~100 km around the position and time reported by CSpOC (the US military tracking network). It could be that the CSpOC position, with the quoted very small uncertainty in time of +- 1 minute, is based on a SBIRS satellite detection of the fireball (we have long suspected that TIP's with such 1-minute uncertainty quotes are based on satellite detections of the reentry fireball). 

About 100 km is a fair altitude for the ablative phase to start, similar to the altitude at which meteoric fireballs start. If the video from Oman above is the real deal, it is indeed suggested that ablation (and break-up) was starting over southern Arabia.

As a further update: interesting information about infrasound detections of the reentry from Djibouti, with source over the Arabian peninsula:

[end of update]

(below is the  pre-reentry  version of this frequently updated post):

(this part below last updated 8 May 23:00 UT)

On 29 May  April, China used a CZ-5B rocket to launch the core module of it's new Space Station Tianhe-1 ("Harmony of Heavens-1"). The module was initially placed in a 41.5 degree inclined, 382 x 171 km orbit and subsequently raised to a 385 x 352 km orbit.

The massive CZ-5B core stage from the CZ-5B rocket used for this launch was left in a 375 x 170 km orbit. Like it's predecessor that flew in May 2020, it was not deorbited after payload release. This likely means that it will come down in an uncontrolled reentry somewhere on May 8 or 9.

Compared to 'normal' rocket upper stages (which are typically 3 to 10 meters long and say 1000-2500 kg in mass), the CZ-5B core stage is huge. It is 31 meters long, 5 meters in diameter, and very heavy: sources differ on the dry mass, but it is somewhere between 17 and 22 tons.


The informal Space industry standard for objects that are heavier than 10 tons, and launched into Low Earth Orbit, is to have a deliberate deorbit over an empty stretch of Ocean. This did not happen with the CZ-5B core stage from the 5 May 2020 launch a year ago, and does not seem to happen now following the Tianhe-1 launch either.

An uncontrolled reentry of an object this large and heavy means that sizable fragments can survive reentry and reach the surface of the earth, with the risk that this happens over inhabited parts of the world. This is not something that you want, from safety concerns. Several analysts have gone on the record calling the lack of a controlled reentry for the CZ-5B core stage 'irresponsible' for that reason.

Indeed, there are risks. For example, sizable fragments from the core stage of the previous CZ-5B launch, that also came down in an uncontrolled reentry, rained down on well populated parts of Ivory Coast in Africa in May 2020.

With the first lauch and uncontrolled reentry of a CZ-5B core stage a year ago, the question was whether a deliberate deorbit was planned but failed, or whether the CZ-5B core stage simply does not have a deorbit capability. As history now seems to repeat with this second CZ-5B launch, it starts to look like the CZ-5B indeed has no deorbit capability. This is highly surprising, and, indeed, irresponsible imho.

At the same time, while there is a risk (see what happened a year ago in Ivory Coast), the risk should not be overstressed. The risk that a random passenger aircraft ends up falling on your house is still orders of a magnitude larger, and we all have come to accept that risk.

We should also realize that much of the 17 to 22 tons mass of the stage will burn up before it reaches earth surface. Moreover, as a large part of the Earth consists of Ocean, it is likely that it will come down harmlessly over some Ocean.

Yet, it cannot be excluded that it will come down over a populated area, so some worry is justified. With an orbital inclination of 41.5 degrees, locations between 41.5 N and 41.5 S are in the danger zone for this reentry. The danger is slightly elevated at the extremes of this (41.5 N and 41.5 S). The latitude range where the CZ-5B booster can come down includes the whole of the United States, Australia, Africa, the southern parts of Asia and much of southern America. Europe is mostly safe, except for Spain, Italy and the Balkans:


When the reentry happens, the rocket stage will break up in the atmosphere and any surviving parts that have not burned up completely will rain down along the ground path along a very long stretch of earth: the area where fragments fall down can be hundreds of kilometers long.



The diagram in the very top of this post gives reentry predictions. I will update it every time I run a new prediction. Below are the same predictions in table form. They are based on modelling of the orbital evolution in the General Mission Analysis Tool (GMAT).

Modelling is done for a mass of 17 tons (note that the true dry mass of the rocket stage is a bit uncertain: quoted values range between 17 and 22 tons, depending on the source) and with a drag surface at 60% of the maximum surface, as I have found that this generally fits well with tumbling rocket stages (which as a result of the tumbling have a variable drag surface). 

Each new prediction is based on a new orbital update from CSpOC. The MSISE90 model atmosphere is used, with past, current and estimated future Space Weather.

Note that these predicted reentry times are nominal values only. PLEASE NOTE THE VERY LARGE UNCERTAINTY IN THESE TIMES! 

The uncertainty margins shown are calculated as 20% of the time between the orbital epoch on which the prediction is based, and the predicted reentry time.

Note that the nominal position shown is only nominal: it is for the center of the uncertainty interval, but as long as the uncertainties in the reentry time measure in the hours, it is basically meaningless.


DATE      *NOMINAL* TIME        (issued)     (*nominal* position)

8 May     19:23 UT +- 22 hr     (May 4.22)

8 May     21:23 UT +- 21 hr     (May 4.46)

8 May     20:40 UT +- 21 hr     (May 4.53)

8 May     19:41 UT +- 20 hr     (May 4.59)

8 May     20:46 UT +- 18 hr     (May 5.08)

8 May     21:36 UT +- 18 hr     (May 5.20)

8 May     21:18 UT +- 16 hr     (May 5.51)

9 May     00:10 UT +- 16 hr     (May 5.58) 

9 May     04:40 UT +- 13 hr     (May 6.50)

9 May     03:52 UT +- 10 hr     (May 7.18)

9 May     04:01 UT +-  9 hr     (May 7.36)

9 May     03:36 UT +-  5 hr     (May 8.17)

9 May     03:10 UT +- 3.5 hr    (May 8.40)   (07 N 108 W)

9 May     03:11 UT +- 1.8 hr    (May 8.77)   (11 N 103 W)

9 May     02:54 UT +- 1.3 hr    (May 8.86)   (31 S 155 W) 

Uncertainties in the predicted reentry times will remain very large untill very shortly before the actual reentry.

click map to enlarge

Within the 2 hour wide uncertainty window of the current CSpOC TIP (9 May 2:04 UT +- 1 hr), which no doubt is more reliable than my amateurish efforts, the rocket stage can come down anywhere on the lines drawn in the map above (the lines show the rocket's trajectory over the uncertainty window). Within the risk window, the trajectory runs over central America, southern Europe, Arabia and the southern tips of Australia. China itself now appears to be out of the risk zone, ironically enough. The nominal point (but: with such a wide uncertainty that it is still basically meaningless!!!) is over Spain

The yellow dots in the map are those cities with populations of a million or more between 41.5 N and 41.5 S.

Other sources of predictions:

Most notably: Space-Track (the CSpOC portal: requires an account), which should be regarded as the most authoritive one.

Also: EU SST on Twitter

...and otherwise: Joseph Remis on Twitter, and Aerospace Corporation 

(note how all of these give somewhat differing forecasts: which shows you how difficult these reentry forecasts are!)

Several years ago I wrote a FAQ about reentries, and reentry predictions, that might answer any questions you have.

I will update this post with new data when I have the opportunity.

Wednesday, 28 April 2021

USA 314 (NROL-82) imaged


click to enlarge

Last Monday 26 April at 20:47:00 UT, ULA launched a classified payload for the NRO under the launch designation NROL-82. The payload is now designated USA 314. I wrote about the launch and that it is almost certainly an ADVANCED ENHANCED CRYSTAL KH-11 electro-optical reconnaissance satellite in an earlier post.

The payload was picked up on the first orbit by radio observer Scott Tilley in Canada, and next, guided by the radio observations, Cees Bassa (who is just like me in the Netherlands) optically imaged it on the second and third orbit.


I tried to image it from Leiden on the second orbit as well, but as it turns out it passed outside my camera field during that pass.

The next night, and with a more firm search orbit based on the data from the previous night available, I did succesfully image it. The photograph in top of this post was made with a Canon EOS 80D camera and Samyang 1.4/85 mm lens (at F2.0, 1600 ISO, 1 second exposure). 

I also obtained video, using the WATEC 902H2 Supreme with a 1.8/50 mm lens:

The payload is designated USA 314 (catalogue nr 48247, COSPAR 2021-032A) and as usual CSpOC does not publish orbital data. But our observations show that it is in a 528 x 755 km, 98.1 degree inclined sun-synchonous orbit.

The orbital plane is even closer to that of USA 224 than anticipated: a difference of only 1.1 degree in RAAN and 0.2 degrees in orbital inclination. The orbital altitude is somewhat different and the orbital eccentricity is less than our initial guess. Perhaps it will manoeuvre over the coming days/weeks to the same altitudes as USA 224, perhaps it will not: we will see!

So in all, the NROL-82 payload's orbit is pretty much what was expected, apart from a slightly different initial orbital altitude.

USA 224 and the new payload USA 314 currently move almost in phase, and as a result they are relatively close, with continuous sight of each other. It is well possible that USA 224 is imaging the new payload as a post-launch health checkup.

The image below shows the coplanar character of the USA 224 and USA 314 orbits, and the spatial proximity in viewing distance of each other:

click to enlarge

As I pointed out in a previous post, based on historical patterns I expect that, after a checkout-phase that may take a couple of weeks, the new USA 314 will take over from USA 224 in the KH-11 primary East orbital plane. USA 224 will then likely be manoeuvered into a lower orbit (~400 km) and its orbital plane will be moved to the 'secondary' East plane, some 10-20 degrees east in RAAN of the current orbital plane.

Sunday, 25 April 2021

An upcoming French ICBM/SLBM test [UPDATED TWICE]

click map to enlarge

UPDATE (see end of post for more info): the test happened and it was an M51 SLBM

Navigational Warnings HYDROLANT 1140/21 and NAVAREA IV 337/21 which appeared today suggest that France will be test-firing some sort of ICBM or SLBM over the northern Atlantic between April 28 and May 21. 

As indicated by the position of area A, the launch will be from from DGA Essais de Missiles, a missile base of the French Military on the coast of the Gulf of Biscaye, some 70 km southwest of Bordeaux. The target area appears to be north of  Bermuda, some 5500 km from the launch site.

250005Z APR 21
HYDROLANT 1140/21(and NAVAREA IV 337/21)
   A. 45-30.00N 006-39.00W, 44-35.00N 001-28.00W,
      44-26.00N 001-16.00W, 44-18.00N 001-17.00W,
      44-14.00N 001-36.00W, 45-08.00N 006-45.00W.
   B. 47-33.00N 019-01.00W, 47-21.00N 015-35.00W,
      45-29.00N 015-33.00W, 45-41.00N 019-12.00W.
   C. 35-50.00N 070-08.00W, 35-50.00N 063-38.00W,
      34-15.00N 063-38.00W, 34-15.00N 070-08.00W.
   D. 46-38.12N 039-31.05W, 45-37.02N 039-15.53W,
      45-53.52N 036-47.10W, 46-54.92N 036-59.92W.
3. CANCEL THIS MSG 211100Z MAY 21.

I have mapped  the four hazard areas from the Navigational Warning in the map in top of this post. Areas A, B and D are along a simple ballistic trajectory. Area C, the target area north of Bermuda, is not (as can be clearly seen), so either the post-boost vehicle or the dummy MIRV's fired from it will take a different course at some point. 

Note that the dog-leg which I have drawn in the map is very hypothetical and not very realistic: its purpose just is to show that the target area deviates from the initial missile trajectory. [added note: it is much more likely that the trajectory changed is effected much earlier in the  sequence]

Depending on the time of, and weather conditions during, this test launch, it might generate some UFO reports from the southwest French and northern Spanish coast.

As far as I am aware of, the French only have SLBM's in operational service at this moment. Their landbased ICBM's were mothballed in 1996. 

So the launch might be a (land-based) launch of an M51 SLBM. The ground range and size of the areas A,B and D with respect to to the launch site are similar to those of another recent French SLBM test, fired from a submarine in front of the Breton coast on June 12, 2020 (I wrote about that test here).

Click to enlarge


I spoke with Joseph Trevithick for this article in The Drive which also has insights from several other experts.

What I did not know, but learned from the article, is that the DGA Essais de Missiles has a pool with a submerged launch platform, so they can simulate SLBM launches from a submarine. So if it is another M51 test, this makes the choice of the launch site less odd.

Here is some footage from an earlier SLBM test from this submerged platform at DGA Essais de Missiles:

(28 April 2021)

The French Ministry of Defense has announced that a successful test with an M51 SLBM was indeed conducted from DGA Essais de Missiles in the morning of 28 April. Bulletin (in French) here.

In the hours around the test, French and US military monitoring planes were in the air near the target area north of Bermuda:


The twitter account of the French Direction générale de l'armement published this video of the launch:


The image below, which is from the bulletin put out by the French Ministry of Defense, may or may not show the actual missile fired:

Thursday, 22 April 2021

NROL-82: an upcoming new KH-11 EVOLVED ENHANCED CRYSTAL launch [UPDATED]

image: ULA

(updated 27 Apr 2021 with first observational orbit, see end of post)

If the weather and the launch Gods cooperate, ULA will launch a Delta IV Heavy with a classified payload for the NRO on 26 April 2021. The launch is designated NROL-82 and the payload will likely receive the designation USA 314. In a tweet from April 19, ULA mentions a prospective launch time of 20:46 UT.

Several lines of evidence lead us to believe that the payload is a KH-11 EVOLVED ENHANCED CRYSTAL optical reconnaissance satellite, colloquially also known as a 'Keyhole'. It is the kind of satellite that makes these kind of detailed pictures of areas of interest for the NRO.

A map in the ULA Mission Overview for this launch, and the Navigational Warnings issued for this launch (NAVAREA XII 173/21 and HYDROPAC 1221/21) provide information on the launch azimuth and from that the orbital inclination targetted. Likewise the position and time window of the upper stage deorbit area provides - in a very broad sense- information on the orbital altitude aimed for. Together they indicate a launch into a sun-synchronous Low Earth Orbit with an orbital inclination near 98 degrees. This is a very familiar orbit, as we will discuss later in this post.

Below is a map I prepared depicting the hazard areas from these Navigational Warnings as well as the launch trajectory I calculate based on this information:

click map to enlarge

The listed times along the track are for launch at 20:46 UT into the 250 x 1020 km, 97.9 degrees inclined estimated orbit below:

 NROL-82 (USA 314)          for launch on 26 April 2021 at 20:46:00 UT
1 70002U 21999A   21116.86527778  .00000000  00000-0  00000-0 0    03
2 70002 097.8600 222.0898 0548970 157.1680 337.2110 14.78203944    02


The text of the Navigational Warnings:

220434Z APR 21
NAVAREA XII 173/21 (also: HYDROPAC 1221/21)
   A. 2016Z TO 2257Z DAILY 26 THRU 28 APR
      34-38N 120-40W, 34-36N 120-30W,
      34-07N 120-39W, 34-08N 120-44W.
   B. 2016Z TO 2257Z DAILY 26 THRU 28 APR
      22-57N 120-46W, 23-47N 125-18W,
      26-27N 124-45W, 25-36N 120-08W.
   C. 2016Z TO 2257Z DAILY 26 THRU 28 APR
      13-28S 121-20W, 10-47S 138-34W,
      00-47S 136-41W, 03-52S 119-54W.
      63-14S 174-16W, 32-49S 159-58W,
      33-23S 156-28W, 64-16S 168-07W.
2. CANCEL THIS MSG 300129Z APR 21.


Area D from the Navigational Warnings, located in the southern Pacific Ocean, appears to be the deorbit area for the Delta Cryogenic Second Stage (DCSS). The DCSS deorbit takes place some two hours after launch, just after the start of the second revolution (with the deorbit burn happening over the Arctic, near the end of the first revolution).

As mentioned above, the orbit that seems to be targetted is one that is very familiar in terms of orbital inclination and sun-synchronous character. It is the typical orbit of a KH-11 EVOLVED ENHANCED CRYSTAL electro-optical reconnaissance satellite. Several years ago I discussed the KH-11 orbital constellation in depth on this blog ("Past and future of the KH-11 Keyhole/Evolved Enhanced CRYSTAL constellation" - 2013). As a side note, the type of rocket used to launch NROL-82 is consistent with a KH-11 launch too: the Delta IV Heavy has a long history of launching KH-11's.

Currently there are at least three, and possibly four active KH-11 satellites on orbit: USA 186 (2005-042A), USA 224 (2011-002A), USA 245 (2013-043A), and possibly USA 290 (2019-004A).  The latter, USA 290, is in an odd orbit for a KH-11 and its identification as a KH-11 is open to questioning (I will discuss this later in this blog post).

Historically (see "Past and future of the KH-11 Keyhole/Evolved Enhanced CRYSTAL constellation"), new KH-11 satellites are launched into one of two primary orbital planes some 48 degrees apart in RAAN: a "primary East" plane and a "primary West" plane. The time window and the 20:46 UT launch time given by ULA for the upcoming April 26 launch corresponds well with targetting the "primary East" plane. This orbital plane results in passes around local noon and midnight. The KH-11 satellite currently occupying this orbital plane is USA 224 launched 10 years ago in 2011.


USA 224 imaged in June 2014. click image to enlarge

KH-11 constellation (minus USA 290), situation mid-April 2021 (polar view). Click to enlarge

The orbital plane of USA 224 passes over the launch site of NROL-82, Space Launch Complex 6 (SLC-6) at Vandenberg Air Force Base, around 21:20 UT on April 26. This is a difference of some 35 minutes with the launch time (20:46 UT) from the ULA tweet.

In 2011, when USA 224 itself was launched to replace USA 161 in the primary East plane, the launch occurred some 20 minutes before the USA 161 orbital plane crossed over the launch site (a similar time difference would hence see launch around 21:00 UT for the upcoming April 26 launch).

If history is our guide, the following sequence of event will likely happen. To start with, NROL-82 will be launched into the KH-11 Primary East plane, with an orbital inclination of ~97.9 degrees and orbital altitude of ~250 x 1020 km, almost co-planar with USA 224. The illustration below shows the orbital plane situation around orbit insertion. Note the similarity of the orbital planes of NROL-82 and USA 224:


expected situation just after launch of NROL-82. click to enlarge


After a check-out period of a few weeks, the NROL-82 payload (likely designated USA 314) will take over the primary plane mission from USA 224, the satellite previously occupying this orbital plane. 

Next, after USA 314 has taken over its role, USA 224 will be moved away from the primary plane, into a new orbital plane with RAAN some 10-20 degrees East of the primary plane: the so called '"secondary East plane". It will also lower its apogee and take up a ~400 km altitude orbit. In this new orbit it will continue to be operational for several years, entering its extended mission phase. 

From this moment on, for the first time since the deorbit of USA 161 in the winter of 2014-2015, all the two primary planes and all the two secondary planes will be occupied by a KH-11 again. The orbital constellation will become something like that in the image below:

Approximate KH-11 constellation after expected rearrangement later this year. Click to enlarge


How about USA 290?

You will have noted that after a brief initial mention, I carefully left USA 290, launched in 2019, out of the discussion so far. So what about that object? Is it a KH-11?

USA 290 (2019-004A) was launched as NROL-71 from Vandenberg on a Delta IV Heavy on 19 January 2019 (see an earlier blogpost) and it was suspected by some noted analysts to be a KH-11. It however went into a weird, 73.6 degree inclined ~400 km altitude orbit that is not sun-synchronous and nothing like previous KH-11 orbits. So, had the NRO broken with the previous 'classic' pattern of the KH-11 orbital constellation and were they trying something new?

The identification of  USA 290 as a KH-11 never has been sitting well with me. The odd orbital inclination and non sun-synchronous character of the orbit gives few reasons to think it is an IMINT mission.

In light of the apparent return to the known 'classic' KH-11 constellation with the upcoming launch of NROL-82, I have again started to foster these doubts. Maybe USA 290 isn't a KH-11 after all but something else, something experimental (readers of this blog will have noted that the past 4-5 years, a lot of NRO launches appear to be experimental, going into 'new' previously unseen types of orbit. Some of these are, I suspect, radar imaging satellites).

Ted Molczan has recently suggested that USA 290 is a KH-11, and that its odd orbit is inspired by that of the notorious 'Misty' stealth IMINT satellites of the 1990-ies which were launched in ~65 degree orbits. Basically, he argues that USA 290 is a 'Misty' imaging satellite without the stealth!

I remain agnostic at best about the identity of USA 290. Perhaps, if new payloads are launched into similar orbits over the coming years, the picture will become more clear. For now, I regard USA 290 as an oddity, and not necessarily a KH-11.

UPDATE 27 Apr 2021 11:00 UT

Cees Bassa optically observed the NROL-82 payload on the 2nd and 3rd revolution. Radio observers including Scott Tilley are also tracking it.

Based on a hybrid optical/radio orbit computed by Scott Tilley, the orbital altitude is somewhat different than expected, the orbit less eccentric: but the orbital plane is even closer to that of USA 224.

The orbital plane is very close to that of USA 224 indeed: a ~1 degree difference in RAAN and 0.1 degree difference in orbital inclination.

Orbital altitude currently appears to be about 525 x 760 km, i.e. less eccentric than our initila pre-launch estimate. That of USA 224 is 256 x 997 km.

The NROL-82 payload might manoeuvre in the coming days and weeks in order to have it's apogee and perigee altitudes match with  that of USA 224.

click to enlarge

Tuesday, 6 April 2021

LUCH (Olymp-K), an eavesdropping SIGINT snooping around commercial comsats


click image to enlarge

Back in 2016, I published an article in The Space Review (A NEMESIS in the sky: PAN, Mentor 4 and Close Encounters of the SIGINT kind) about the mysterious US classified satellite PAN, and Mentor 4, another classified US satellite.

Both are SIGINT satellites launched in 2009, that are positioned close to commercial telephony communications satellites in GEO in order to eavesdrop on their communications. While Mentor 4 (an ADVANCED ORION) dedicatedly covers Thuraya 2, PAN (NEMESIS 1) moved from satellite to satellite in a 'roving' role every few months during the first 5 years of its operational existence. Its sister ship CLIO (NEMESIS 2) launched in 2014 has done pretty much the same.

But (of course) the USA is not the only country playing this game. In the same year that CLIO (NEMESIS 2) was launched, the Russian Federation launched LUCH (2014-048A), aka OLYMP-K or OLIMP-K. In 2015, in an essay in The Space Review, Brian Weeden pointed out that LUCH was roving from satellite to satellite too, possibly eavesdropping on their communications. This created headlines at the time. By all means, LUCH/OLYMP-K is the Russian equivalent of PAN and CLIO.

The diagram below shows the frequent repositionings of LUCH/OLYMP-K over the years ( a table with major repositionings is at the end of this post):

click diagram to enlarge

LUCH has recently (in the second week of February, 2021) been relocating from longitude 3 W to 8 W and is now positioned near EUTELSAT 8 WEST B (2015-039B). Before the relocation, it had been close to ABS-3A (2015-010A) for several weeks. 

I shot this image below on March 29th, when LUCH and EUTELSAT 8 WEST B were about 90 km apart:


click image to enlarge

The image was made with a CANON EOS 80D and Samyang 2.0/135 mm lens (10 seconds at 1000 ISO) and was a by-product of targetting MEV-2 and several classified objects in this stretch of sky.

The table below gives longitudinal positions for LUCH/OLYMP-K. The table focusses on major relocations.

Dates refer to he moments the longitude appears to get stabilized, and have generally been preceeded by a period of drift. Also indicated is what satellite was closest to LUCH/OLYMP-K at the start of each stable period. Note that in several cases, multiple satellites were close by and possibly targetted as well.

TABLE: positions of LUCH/OLYMP-K since late 2014 

DATE          LON      NEAR

17-02-2021    08.1 W   EUTELSAT 8 West B       2015-039B
06-11-2020    03.1 W   ABS-3A                  2015-010A
28-09-2020    04.9 W   Eutelsat 5W B           2019-067A
11-05-2020    01.1 W   Intelsat 10-02          2014-058A
28-03-2020    21.5 E   EUTELSAT 21B            2012-062B
28-11-2019    70.6 E   EUTELSAT 70B            2012-069A
22-10-2019    68.4 E   Intelsat 20             2012-043A
25-08-2019    65.9 E   Intelsat 17             2010-065B
01-07-2019    64.0 E   Intelsat 906            2002-041A
21-02-2019    60.0 E   Intelsat 33E            2016-053B
28-10-2018    57.0 E   NSS 12                  2009-058A
03-07-2018    49.9 E   Turksat 4B              2015-060A
07-06-2018    48.0 E   Eutelsat 28B            2008-065B
27-04-2018    47.5 E   Yahsat 1B               2012-016A
17-01-2018    41.9 E   Turksat 4A              2014-007A
25-10-2017    38.1 E   Paksat 1R               2011-042A
18-08-2017    32.7 E   Intelsat New Dawn       2011-016A
14-09-2016    09.9 E   Eutelsat 10A            2009-016A
11-01-2016    01.1 W   Intelsat 10-02          2004-022A
05-10-2015    24.3 W   Intelsat 905            2002-027A
26-06-2015    18.1 W   Intelsat 901            2001-024A
22-02-2015    96.4 E   Express AM-33           2008-003A

Tuesday, 30 March 2021

[UPDATED] Cosmic Ballet: approach of MEV-2 and Intelsat 10-02 imaged

image from 2 April 2021. Click image to enlarge

At geosynchronous altitudes, a cosmic ballet is happening between Intelsat 10-02 (2004-022A) and MEV-2 (2020-056B). I imaged the pair last night, spurred to do so by Bob Christy. The pair was almost due south at 30 degrees elevation for me. 


click image to enlarge

click image to enlarge

A small complication was imposed by the current Corona-curfew, as it means I cannot go out to the spot where I normally photograph geosynchronous objects: so I had to target the camera through the loft window (which has a limited FOV).

MEV-2 ("Mission Extension Vehicle 2") is the second of Northrop-Grumman's satellite servicing missions. It's mission is to dock to Intelsat 10-02, a communication satellite launched in 2004, and extend the lifetime duration of this satellite by 5 years, providing it with fresh fuel and a new engine.

MEV-2 has made a number of close approaches to Intelsat 10-02 over the past weeks (see Bob Christy's detailed account of their movements on his website), in preparation for docking..

The MEV-2 predecessor MEV-1 successfully docked to Intelsat 901 in February of 2020 and then brought it from a graveyard orbit into an operational geosynchronous orbit. It also had to make several close approach attempts before effecting the docking at the time.

In the image above, I have labelled the brightest object as Intelsat 10-02 and the fainter one as MEV-2. Space-track has it the other way around, but according to observers who are following the duo for a while, they have mixed up the ID's. This often happens with objects close to each other in GEO, as it is acknowledgedly difficult to keep track of which is which. In this case, the brightness difference of the objects provide a  way to discern them. One expects Intelsat to be brighter than MEV-2.

The image is a 10-second exposure with a Canon EOS 80D and a Samyang 2.0/135 mm lens at ISO 1000.

UPDATE 1  30 March 2021 22:00 UT

I imaged MEV-2 and Intelsat 10-02 again this evening. They are still in the same relative position to each other as yesterday. The image below is a stack of 10 images (10s exposure each): the stack brings out the fainter MEV-2 a bit better than in yesterday's single image sabove.

click image to enlarge

Space-Track has, in their latest orbital updates, switched the identities back to what they should be, now designating the fainter object as MEV-2. You'd almost say they read my tweets... ;-)

UPDATE 2, 2 April 2021 13:00 UT:

Lats night was clear, so I imaged the duo again, after they came out of earth shadow. Due to the good phase angle, they were quite bright. Several other geosats visible in the vicinity as well. The image below was shot at 00:52:57 - 00:53:07 UT on April 2 (1600 ISO, 10 seconds, Canon EOS 80D + Samyang 2.0/135 mm):

click image to enlarge