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I checked 2018-099 in Celestrak's satcat again for the question Where can I find the TLE of ExseedSat 1, India's first ever private LEO satellite? and noticed that the last object listed is 2018-099BS 43822 OBJECT BS has a source/ownership of TBD and a Orbital Status Code of NEA meaning no elements available.

What is Object BS, and how can it have an entry in the satcat without any orbital elements? Is this a lost satellite from the payload, or some bit of broken material that fell off? April 1st is a long way off...

It's the only line in 2018-099 without an * in column 21.

OBJECT BS


Please no "I suspect..." answers. If it is known please post, but for this question pure speculation doesn't count without some supporting source(s). However, a documented similar situation that was resolved could be a supporting source. Thanks!

Update: Object BS's entry in the satcat has been modified/upgraded, it shows some nominal orbital elements

2018-099BS   43822     OBJECT BS                 TBD    2018-12-03  AFWTR                 96.3   97.8     594     571     N/A   
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    $\begingroup$ Er... Do you have an idea what is the "Object BQ"? And other objects called "Object X"? I'm not into sattelite tracking, but would suspect that's various debris $\endgroup$ – OON Jan 29 '19 at 5:23
  • $\begingroup$ @OON there are still known payload objects that have not been assigned. I've linked to a question about one of them in the first sentence. So one can't simply "suspect" that every object without a name is "various debris" which is why I've asked for more than an "I suspect..." answer. I haven't found a listing of the total number of payloads for the launch yet. That would be helpful in finding out how many known payload objects are still unaccounted for eight full weeks after launch! $\endgroup$ – uhoh Jan 29 '19 at 7:49
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Answering almost a year later... This was a particularly hard launch for JSPOC to track. The systems, processes, databases, etc are not well set up for a launch with a hundred+ objects.

It looks like a year later, 43822 still shows up as Object BS, and there are several other equally unidentified objects: Object X (43779), Object BE (43810), and others. This is true both on Celestrak and space-track as well websites that derive TLEs from them such as N2YO.com

Jonathan McDowell's Launch Log has 43822 listed as "VisionCube". Interestingly for VisionCube the Nanosat Database claims that no signal was received, and states that they are not even sure it actually launched. VisionCube is a 2U satellite from South Korea. Jonathan often gets information from other sources beyond space-track/celestrak. I don't know if the assignment of 43822 to VisionCube was insider information or a guess.

SatNogs, the open source ground station network shows "VisionCube" as active, although it only has 4 "successful" contacts since launch, so it is questionable whether they are actually tracking it. My guess is that it is an error in the entry because 1) they have it as catalog number 99930, which is not a real catalog number and 2) it is shown in a mid inclination orbit rather than the sun-sync orbit it should be in. If SatNogs is not using a real catalog number, I'm not sure where they would be getting their TLEs for tracking from.

Several places have the web site for VisionCube as: http://control.kau.ac.kr/visioncube/visioncube-2/ However it fails to load for me.

Bottom line - the JSPOC has limited ability to know which satellite is which, especially on these multi CubeSat launches. A 2U Cubesat will look like another 2U Cubesat on radar and optical. No way for them to differentiate. As a result they will sometimes leave objects as unidentified, and other times take a best guess based on something. Unless the actual operators post specific information identifying their satellite, these guesses go uncorrected. And of course, for the operators to identify their satellite, it needs to be alive!

I personally had a Cubesat on one of the first big multi launches, the ORS-3 launch back in 2013. At the time, it broke the record for number of satellites on one rocket, although the new record stood for only a few weeks. My 1U satellite, TJ3Sat from Thomas Jefferson High School was in the same deployer as Black Night, also a 1 U, from West Point. Neither satellite was ever heard from. Yet a few months after launch, TJ3Sat was assigned 39385 and Black Knight 39398. Both satellites in the same deployer, both 1U, both silent. I don't see how JSPOC would have been able to tell them apart, but somehow they each got a catalog number. That launch had 8 or 9 dead satellites, and I'm guessing at some point they just did a random assignment of dead satellites to unknown objects. But that is just a guess.

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  • $\begingroup$ Thanks! I wonder if something happen that suddenly made this answerable, or you just got reminded that this question was still out there and tracked down the answer. Either way, it's good to know it was a valid question and I didn't just pick "BS" for the heck of it ;-) $\endgroup$ – uhoh Dec 19 '19 at 16:50
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    $\begingroup$ I just happened to run into the question as I was perusing unanswered questions. $\endgroup$ – Carlos N Dec 19 '19 at 17:36

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