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.

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