Wednesday, 20 April 2022

USA 327 / NROL-85

The video above which I shot yesterday evening (19 April 2022) shows USA 327, the NROL-85 payload, passing over my home in Leiden, slightly over two days after it was launched. The footage was shot with a WATEC 902H2 Supreme Low Light Level CCTV camera with a Canon FD 1.8/50 mm lens fitted.

NROL-85 (see two previous posts about this very recent classified launch here and here) has now been catalogued (with orbital elements witheld) by CSpOC as USA 327, catalogue nr 52259, COSPAR ID 2022-040A. Only one object was catalogued, there was no spoof second 'debris' object entered.

As already mentioned in a recent post, the fact that there is no second object is a big surprise. We expected NROL-85 to deliver two payloads, a pair of INTRUDER (also known as NOSS, which stands for Naval Ocean Surveillance System), SIGINT satellites used for geolocating shipping on the High Seas by means of time difference of arrival of their radar/radio emmisions.

Before 2001, NOSS systems existed of three co-orbiting satellites forming a thight triangular formation. From 2001 onwards (with the launch of NOSS 3-1, the first of the Block 3 NOSS-es) , this changed into two co-orbitting satellites.

(the video below, from 30 August 2018, shows a typical NOSS pair, in this case both briefly flaring due to a favourable sun-satellite-observer angle on some reflecting part of the satellites. While operational, NOSS pairs always move this close together. The NOSS pair in question is  NOSS 3-6, the same NOSS pair into which orbital plane the new USA 327 satellite was launched).

And now, we have only one, not two, satellite launched in a NOSS-like orbit. Analysts are scratching their heads over this.

Given the strong similarity in orbit, and the fact that it was launched into the orbital plane of an existing 10-year-old NOSS pair (see previous post), NOSS 3-6 (2012-048A & P), there is clearly some conceptual link of the new satellite to the NOSS program

But in what way exactly? There are a couple of options:

(1) This is a new generation of NOSS/INTRUDER, (i.e. NOSS block 4-1), that needs only one satellite;

(2) This is something else, something new, but related to NOSS/INTRUDER;

(3) This was meant to be NOSS 3-9, a regular NOSS pair, but something went wrong and the second satellite was not deployed;

(4) There is a second satellite but it is small (cubesat) and not yet detected;

(5) The second satellite still has to detach from the first


So let us briefly comment on these various options:

Option (1) apparently, is feasible, according to some. Apparently it is possible to do TDA using just one satellite

With regard to option (2), the most interesting one, one could think of for example an optical or radar counterpart to the existing NOSS 3-6 SIGINT pair: one that images the ships geolocated by NOSS 3-6. This makes sense (and it also makes sense that the new satellite orbits half an orbit apart from the NOSS pair).

While we cannot exclude option (3), I think it is not the most likely option. The same goes for option (5): with previous NOSS launches, two objects were detected right after launch. I have no opinion on option (4).

If we look at the current orbit of USA 327 and the orbit of the NOSS 3-6 pair, we note that: 

(a) they move in almost the same orbital plane; 

(b) they currently are almost exactly half an orbital revolution apart (see illustration below); 

(c) because of the latter difference in Mean Anomaly, their ground tracks are not the same but have some distance between them.


click map to enlarge

Observation (c) does not entirely make sense to me. Wouldn't you want your imaging satellite to follow the same ground track as the geolocating SIGINT satellites? On the other hand: true: the footprints are large enough to cover a large overlap in ocean space from both groundtracks. But still....

Another aspect of this that does not completely make sense to me is that, if USA 327 is a technology demonstrator for a new complementary IMINT mode to the NOSS SIGINT system, then why pick a 10-year-old, nearly retired pair of NOSS satellites to test it with? Why not pick a fresher pair, so you can happily experiment away for the time to come?

But maybe, those fresher pairs of NOSS satellites are deemed more suited for when, after this technology demonstration, the truely operational system is deployed. But then again, why bother with that, just replace the technology demonstrator with the operational version and deorbit the technology demonstrator.

Questions, so many questions, and my still post-COVID impaired brain cannot make much sense of it yet...

It will be interesting to see what USA 327 does (in terms of orbital manoeuvres etcetera) the coming months.

Meanwhile, Radio observer Scott Tilley in Canada has detected the first S-band radio signals from USA 327. He reports "huge fades in signal", which is odd. From Cees Bassa I understand that the frequency in question, 2277.5 MHz, is a know frequency used during the checkout-phase of NOSS 3-x pairs.

A surprisingly bright flare from a 6U Cubesat

​The 240 frames frame stack above, which is from the video below, shows the classified Japanese satellite IGS Optical 5 (2015-015A). But at 21:14:05.5 UT, somethings else moving nearly parallel to the satellite briefly flares up.

The flaring object in question, producing a flare of at least magnitude 0, is TYVAK 182A (also known as ELO Alpha), 2021-034D. This is a 6U cubesat. I am quite surprised to see such a bright flare from such a small object!

The video was taken from Leiden, the Netherlands, with a WATEC 902H2 Supreme fitted with a Samyang 1.4/35 mm lens.

Monday, 18 April 2022

NROL-85 observed, but is it an INTRUDER/NOSS or something else? [UPDATED]

click image to enlarge


Yesterday 17 April 2022 at 13:13 UT, SpaceX launched the classified NROL-85 mission for the NRO. Before the launch we widely expected this to be NOSS 3-9, a new pair of INTRUDER/NOSS satellites (see previous post), based on clues as to the orbit it was launched into. 

The orbital inclination and orbital altitude suggested by OSINT infornation on the mission were typical for NOSS/INTRUDER, and the time of launch indicated a launch into the orbital plane of the 10-year-old NOSS duo NOSS 3-6. That is a pattern we have seen before with NOSS missions: a replacement launched into the same orbital plane after 10 years of operational service.

So we expected to observe two objects after launch. 

But NROL-85 had a surprise in store: so far, we detected only one object, not the expected two!

This leads to the question: is NROL-85 a new INTRUDER/NOSS, or not?

NROL-85 was first picked up by me, from Leiden, the Netherlands, some 7 hours after launch, in late evening twilight of 17 April around 19:59 UT (21:59 CEST). It was some 2.5 minutes early on my pre-launch estimated search elset. I subsequently also observed it on a second pass two hours later.

On the first pass, I captured it photographically (see image in top of this post, showing it above the roof of my house along with two old unrelated rocket stages), using a Canon EOS 80D with a Samyang 1.4/35 mm wide angle lens (the exposure is a 2-second exposure at ISO 800). The video system I had set up captured it too, but only very briefly in a corner of the field of view. Only one object was seen, nothwithstanding that I did a photographic plane scan during quite some time.

The second pass was in the northern sky with a less favourable phase angle (so the object was much fainter than during the first pass). I captured it with the video system, and after following it for a minute or so, left the camera stationary to look for a possible second object. None was detected, either before or after the detected object.

Likewise, fellow observers from the Seesat-L list including David Brierley and Eelke Visser, detected only one object too. And Scott Tilley reports that he did not detect radio signals at the frequencies usually used by NOSS.

The absence of a second object could mean that NROL-85 is not a new INTRUDER/NOSS mission after all, but something else, although the orbit is very NOSS-like.

Alternatively, perhaps it is an improved version of INTRUDER that now needs only one satellite, rather than two.

NOSS missions once consisted of three satellites orbiting close together in a triangular formation. In 2001 this changed to two satellites. Maybe now they found a way to do it with one satellite?

The object we detected is in a 1021 x 1191 km, 63.5 degree inclined orbit (update: with a longer observational arc constraining the eccentricity of the orbit better, the new value is ~ 1008  x 1207 km). This orbit is close to the specifications given in a launch contract tender for NROL-85. Below is a preliminary initial elset based on a 5.5 hour observational arc:

NROL-85 (USA 327)
1 70002U 22999A   22108.04497945 0.00000000  00000-0  00000+0 0    07
2 70002  63.5043 123.5866 0114230 185.9890 173.9785 13.40421486    07

rms 0.024 deg

Elset update (20 April 2022): Below is the latest elset based on 114 observations by Cees Bassa, Eelke Visser, David Brearley, Andriy Makeyev and me over a two-day observational arc:

USA 327 (NROL-85)                                      1008 x 1207 km
1 52259U 22040A   22109.98456423 0.00000000  00000-0  00000+0 0    08
2 52259  63.4462 118.5572 0132890 178.9713 181.1610 13.40467640    01

rms 0.011 deg    arc Apr 17.83 UT - Apr 20.01 UT


click to enlarge

As a final note: the post-deorbit-burn fuel vent by the Falcon 9 upper stage used for the launch of NROL-85, which was deorbitted over the Pacific Ocean at the end of the first revolution (see map in previous post), was seen and filmed from Hawaii, showing the characteristic spiral shape:


(a follow-up post is here)

Tuesday, 12 April 2022

NROL-85: probably NOSS 3-9, a new pair of INTRUDER Naval SIGINT satellites


image: Wikipedia

 EDIT (15 & 16 Apr):  the launch of NROL-85 has been postponed by at least two days, 'due to technical difficulties'

EDIT (17 Apr): new launch date is 17 April 2022 13:13 UT

On 15 April 2022, at 13:41 UT (or later) according to a tweet by the NRO, SpaceX will launch NROL-85 for the National Reconnaissance Office (NRO). The launch will be from SLC-4E at Vandenberg SFB. [edit 16 Apr: launch was postponed to 17 April 13:13 UT]

NROL-85 is almost certainly a pair of NOSS satellites. NOSS stands for Naval Ocean Surveillance System; they are also known under the code name INTRUDER. If correct, the duo would become NOSS 3-9 (the 9th mission of block III). It will probably enter with the designation USA 327 in the CSpOC catalogue (with orbital elements witheld).

NOSS satellites are SIGINT satellites operated by the US Navy. They geolocate shipping on the high seas, by detecting their radio/radar emissions. They always operate in close pairs. The secondary object is usually listed (with orbital elements witheld) as "debris" in the CSpOC catalogue, but this is a ruse that fools nobody: it is a payload too that manoeuvres and keeps a careful constant close distance to the primary satellite.

Information from the launch contract tender for this launch reveals that the mission aims for a semi-major axis of  7500.5 km, an orbital eccentricity of 0.0131, an orbital inclination of 63.535 degrees and an argument of perigee of 190 degrees (i.e. perigee almost on the equator). The listed semi-major axis and eccentricity translate to a 1024 x 1221 km orbit

The combination of the 63.5 degree orbital inclination and 1024 x 1221 km orbit strongly points to a NOSS/INTRUDER mission. These typically have an orbital inclination of 63.4 degrees and a semi-major axis of 7485 km, values close to those quoted for NROL-85. If launch is indeed at 13:13 UT on April 17, the resulting orbital plane will be very similar to that of the existing NOSS 3-6 duo (2012-048A and 2012-048P) which was launched in 2012, as can be seen in the figure below. That also lines up with a new NOSS-launch: NOSS-pairs are typically replaced after 10 years on-orbit.

The shift in launch time with date due to the two launch postponements agree with the estimated orbital altitude and orbital plane and matches the nodal precession of a typical NOSS orbital plane.

click image to enlarge


The Navigational Warnings for this launch (NAVAREA IV 336/22 NAVAREA XII 228/22 and HYDROPAC 987/22) define a launch direction towards the south-southeast, and agree with the 63.5 degree orbital inclination of the launch contract tender. 

[EDIT: The first NavWarning has been corrected: I initially copied the wrong NavWarning for this post.....]

100706Z APR 22
NAVAREA XII 228/22(18,21).
   A. 34-41N 120-38W, 34-39N 120-40W,
      34-28N 120-38W, 34-04N 120-17W,
      34-04N 120-05W, 34-19N 120-14W,
      34-39N 120-19W.
   B. 32-03N 118-53W, 32-01N 118-49W,
      30-51N 117-56W, 30-21N 117-39W,
      30-08N 117-47W, 30-11N 118-01W,
      30-32N 118-18W, 31-54N 118-53W.
2. CANCEL THIS MSG 161614Z APR 22.

100644Z APR 22
HYDROPAC 987/22(22,83).
DNC 06.
   1425Z TO 1649Z DAILY 15 AND 16 APR
   20-12S 123-30W, 19-00S 119-00W,
   33-48S 109-30W, 36-00S 114-12W.
2. CANCEL THIS MSG 161749Z APR 22.


I have mapped the hazard areas from the Navigational Warnings and the resulting launch trajectory in the map below (the times listed along the trajectory are in UT and for the updated launch date with launch at 13:13 UT (17 April):

click map to enlarge

Based on the parameters from the launch contract tender, this is my orbital estimate, valid for launch at 13:41 UT on April 15 updated for launch at 17 April 13:13 UT:

NROL-85                         for launch on 17 Apr 2022 13:13:00 UT
1 70002U 22999A   22107.55069445 0.00000000  00000-0  00000+0 0    02
2 70002  63.5350 124.8521 0131000 190.0000 291.3542 13.36458926    04


There is an uncertainty of several minutes in pass time in this elset, progressively so after more than one revolution, and some cross-track error is possible. But the elset should be good enough for a plane scan, taking a wide time window around a predicted pass. Be carefull not to misidentify the NOSS 3-6 duo as NROL-85. An elset for NOSS 3-6 can be found here.

If the eventual launch time turns out to be later than 13:13 UT, the elset above can easily be adjusted to match the new launch time using my "TLE from Proxy" software downloadable here.

The Northern hemisphere will see good, fully illuminated evening passes on the day of launch and the days after it, so prospects are good for a quick on-orbit detection after launch.

The Falcon 9 upper stage deorbit is over the southern Pacific, just after the end of the first revolution. The deorbit-burn might be visible from south and/or central Asia.

The launch patch (see top of this post) features a cat, with a tiger as its reflection. The NRO itself explains some of the symbolism in the patch in this way:

"In the NROL-85 patch, the 3 stars represent guidance, protection, and allegiance. The cat represents loyalty and devotion shared among our nation and partners. The tiger in the cat’s reflection demonstrates that while space can be challenging, a determined attitude helps NRO succeed in going"

Given that this is going to be NOSS 3-9, the 9th instance of the Block III NOSS generation, I wonder if the cat was inspired by the proverbial 'nine lives' of cats.

It is possible that a number of other small satellites will be included in this launch as a rideshare.

The NRO press kit for NROL-85 is downloadable here.

FOLLOW-UP POST HERE reporting the first observations of NROL-85 from the evening of April 17. NROL-85 might not be an INTRUDER/NOSS after all!

A SECOND FOLLOW-UP POST HERE, going a bit deeper into various speculations about what the NROL-85 payload might be.

[a small update to this post was made 13 April 2022 09:00 UT, adding a bit more background information]

[an error where I had initially copied the wrong text of a NavWarning into this post was corrected at 13 Apr 20:30 UT - many thanks to the anonymous sharp-eyed reader who noted it!] 

[updated April 15 & 16 to reflect launch postponements] 

[updated 17 Apr 8:45 UT with updated launch trajectory map and orbital plane diagram]