edit: This must be some kind of record! (cf. ISRO's PSLV-C37 with 104 satellites - after 56 hours only six TLEs, which factor is greatest challenge? This time its only six total!)

At the end of every episode of old US TV game show called "To Tell the Truth" the moderator would ask for the real contestant (one of three) to "please, stand up". (example ending)

As of 29-Jan-2018 03:25 UTC:

Both N2YO and Wikipedia (German) say that Humanity Star is 43166, 2018-010D, but Wikipedia (English) says it is 43168, 2018-010F, and NY2O's current ground track positions for D and F both disagree with the position on TheHumanityStar.com's tracking page, and Celestrak's SatCat listing does not show names for any of the 2018-010 objects yet, although Celestrak's TLE for the A object shows the name DOVE PIONEER.

Question: What is the Humanity Star's actual identity? Will the real Humanity Star please stand up?

below: Simultaneous screen shots for D (labeled Humanity Star) and F via N2YO and Humanity Star via the official site:

enter image description here enter image description here enter image description here


First of all, it isn't really known yet which object it is, at least to the general public. Space Track (JSpOC) no doubt knows which object it is, but it would require them confirming it to the public to get the positive identification. In order for them to release this information to the public, it requires a high level expert to confirm the information, who normally doesn't work on weekends or nights. I expect the confirmation will be done today.

That being said, there are a few bits of information we can use. Of the 6 objects that are being tracked, 3 of them are in a lower orbit then the others. We know from publicly released information that Humanity Star is supposed to be in the lowest orbit. One of these objects is positively identified, meaning that it must be one of the two remaining objects, D or F.

Given that Humanity Star was a secret payload, not announced to the general public until after launch, I suspect that it was given the last designated payload slot. In addition, "F" is the lowest object at the moment, and is given a "Large" Radar Cross Section (RCS) size by JSpOC, as is object "D". It seems like Small, Medium, and Large are the most commonly given values for the RCS size.

Lastly, the common convention of JSpOC is to give all payloads the first levels, followed by any booster stages, and finally any debris objects. It is worth noting that there are 4 "Payloads" that were launched, in addition to 2 "Booster" objects.

That being said, I'm confident that JSpOC things that "D" is Humanity Star", and "F" is the spent second stage booster. "E" would be the spent third stage booster, and "B" and "C" should be the two Lemur satellites. I wouldn't make anything official until JSpOC releases the designations, but I believe 43166 is the proper designation for Humanity's Star.


So, I was wrong, the real one is the "F", 2018-010F 43168. I suspect that the two looked alike, and they initially guessed wrong between Humanity Star and the booster stage.

  • $\begingroup$ It's been about ten days now. This seems quite a long time for them to continue to be confused about six objects. $\endgroup$
    – uhoh
    Feb 1 '18 at 14:35
  • 1
    $\begingroup$ I'm 99% sure JSPOC knows, they just haven't been able to release the information for some reason. It seems like none of the names are getting permanent names, so I think they just don't have the right person around for some reason, and it's usually not considered that urgent. I've been checking every day for confirmation, but... $\endgroup$
    – PearsonArtPhoto
    Feb 1 '18 at 16:02
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    $\begingroup$ @uhoh Okay, so confirmed, it is "F", not "D". I was wrong... $\endgroup$
    – PearsonArtPhoto
    Feb 8 '18 at 17:35
  • $\begingroup$ That's great, thanks for keeping a close eye on this! So B and D are Electron rocket bodies, and the Lemurs are C and E now, according to the Celestrak SatCat updates. Interestingly the German Wikipedia page changed to D to agree with the English page, and the Humanity Star website's map doesn't seem to exactly match N2YO for any of them! $\endgroup$
    – uhoh
    Feb 8 '18 at 21:06

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