Tracking the Dark Side on a shoestring budget

From January 23 to 26, 2023, I attended the 2nd NEO and Debris Detection Conference at ESOC in Darmstadt, Germany. I had a poster-presentation on  the work we Independent Space Observers (ISO's) from the SeeSat-L mailinglist do on tracking classified objects.

The resulting 6-page Conference Paper, co-authored by Cees Bassa and Ted Molczan and titled "Tracking the dark Side on a shoestring budget", has now appeared in the on-line conference proceedings. The PDF can be downloaded here.

 

Abstract: 

A lot of SSA work on earth-orbiting satellites can be done with modest, off the shelf equipment. This has been shown by an informal group of Independent Space Observers (“ISO’s”) organized around the Seesat-L mailing list. They optically track some 200 “classified” objects – objects for which orbital elements are not provided in the public orbital catalogues – using very simple equipment: from binoculars and stopwatch on the ‘old skool’ end to DSLR’s or sensitive CCTV or CMOS/CCD cameras with fast photographic lenses and GPS time management on the sophisticated end. In this paper, a brief outline is provided on the techniques and equipment used by Seesat-L members and an example is given of how a new launch is located and tracked. It is discussed why the whole concept of keeping the orbits of certain space assets “classified” is problematic: not only is it unrealistic, but it also goes against core notions of transparency and accountability regarding activities in space.

Conclusions: 

A group of Independent Space Observers (ISO’s) has demonstrated that tracking large and medium sized artificial objects in earth orbit, and occasionally even smaller ones such as cubesats, using relatively inexpensive equipment made of commercial-off-the- shelf components is feasible. Such relatively low cost equipment could be a way forward to quickly add optical tracking capacity to increasingly strained tracking networks, especially with the rise of mega-constellations. ISO’s have also demonstrated that certain objects whose orbits are kept “classified” by the responsible Nations, can often easily be observed using such equipment. This underlines how highly unrealistic it is to expect that the orbits of certain (military) space assets can be kept ‘secret’. From the viewpoint of Space traffic management, it is actually undesirable to have a situation where the presence of certain classes of tracked objects are kept undisclosed. The practise moreover goes against core notions of transparency and accountability regarding activities in space, such as laid out in Resolution 222 (XXI) of the United Nations (the ‘Outer Space Treaty’

Meet the amateur astronomers who track secretive spy satellites for fun

Somehow I totally forgot to post this here: but after the Zuma launch and subsequent rumours of a failure made headlines, I was interviewed by Mary Beth Griggs of Popular Science magazine. It resulted in a very nice article about our amateur tracking activities, that you can read here.

Tracking stations along UARS final track - a reconstruction [UPDATED TWICE]

click map (revised version) to enlarge

Above map provides an overview of groundbased tracking stations in the ESA ESTRACK and the US AFSCN network that are near or on the final trajectory of UARS. For relevant trackings tations, times of Advance of Sight (AOS) or Loss of Sight (LOS) are indicated. UARS is depicted at the point of reentry (see previous post) as indicated by SSC.

From the NASA talk by Johnson, they pinpointed the 04:00 +/- 1 minute UTC time and 14.1 S, 170.2 W location of UARS's demise using detections and non-detections by "a number of sensors".

As shown above, the last of these tracking facilties, the ESA station at Awarua, New Zealand, would have detected it and tracked untill it lost sight at 3:56 UTC. Next, there is an 11 minute coverage gap untill it could first have shown up at the Kaena Point tracking facility in Hawaii at 4:07 UTC. [EDIT: it appears that Awarua is a telemetry station only, not a true tracking station. As UARS was a dead satellite not sending telemetry, it then becomes unlikely Awarua played any tracking role: leaving nothing between Kerguelen and Hawaii. Thanks to Dan Fischer for querying me about the character of Awarua station]

As can be seen on the map, none of the regular tracking stations had direct coverage of the reported reentry location, begging the question where the "large number of detections" NASA's Johnson was talking about comes from. UARS could first have shown up at the Kaena Point tracking facility in Hawaii at 4:07 UTC. At that time, it would have been without groundbased tracking for quite some time already (over half an orbit).

Of course, we cannot exclude that a temporary tracking facility (e.g. an AEGIS ship) was employed in Polynesia at the time, providing additional data.

Also, a reader of this blog wrote to me with the suggestion that the US Navy's sensitive network of hydrophones could have picked up a signal when wreckage hit sea surface. I have no idea how feasible that is.

I still feel space-based observations were possibly involved (see my earlier post here), but are not being publicly acknowledged. The early warning satellites DSP F20, DSP F16 and SBIRS Geo-1 would have had coverage of the reentry location.

(note added: if anyone knows of additional tracking stations along the trajectory, info is welcome)

Infrasound?

Note added 29 Sept 2011
Dan Fischer raised the option in the comments that Infrasound detections could be involved. Indeed, this is a possibility (I consulted a Dutch infrasound researcher for an opinion here, and he thinks it is feasible, especially if sonic booms were involved) even though the distances to infrasound arrays involved are large.
A number of infrasound arrays are scattered over the Pacific area, listening for possible atomic detonations in breach of the Nuclear Test Ban treaty. A map of them can be found here. In the wider area, such arrays are located on Tahiti (French Polynesia), Hawaii, the Marquesas and New Caledonia. The UARS reentry location is within this triangular area. Below is a map of infrasound detection arrays located in the Pacific around the published UARS reentry location.

Edit late 29 Sept: Dutch infrasound researcher Läslo Evers just notified me he has checked the Tahiti and New Caledonia infrasound records for the reentry - he finds no sign of it.

click map to enlarge