# Why is the NORAD Catalog number of SpaceX's Starlink's “Darksat” both 71130 and 44972?

At the moment it shows:

Internatnl   NORAD          Name            Period   Incl.    Apo  Peri    Eccentricity
Designator   Catalog                        (min)   (degs)   (km)  (km)
Number

2020-001BL   71130  STARLINK-1130 (DARKSAT)  91.12  53.00    333   326     0.0005603


But from Celestrak's Satcat at the moment: https://celestrak.com/pub/satcat.txt

2020-001BL   44972  *+ STARLINK BL               US     2020-01-07  AFETR                                                 N/A


Question: In these two Celestrak lists, for the object 2020-001BL why is the catalog number given as 71130 in one but 44972 in the other?

note: answer(s) to Why are there some NORAD catalog IDs larger than 80000 in space-track? only explain numbers above 80000, but this is in the 70000's.

update 1: A new batch has just been launched and they are once again in the 7100's

update 2: An even newer batch has just been launched and they are once again in the 7100's

• In regards to your note/link about the 80K objects... Historically, 60K's,70K's, 80K's, and 90K's have all been used, in classified and unclassified settings, for analyst objects, simulated objects, and 'known' objects. – costrom Feb 18 '20 at 18:45
• @costrom Thanks, that's great to know! If it's possible to dig up a supporting link or reference for that in some way, then it's going to be an excellent answer. – uhoh Feb 18 '20 at 21:31

As I mentioned in a comment, without source at the time...

SATCAT numbers 70000-99999 (70'000s, 80'000s, and 90'000s) are "analyst objects". This article from The Space Review indicates that these ranges had special uses, from the very beginning of the SATCAT:

When the SATCAT was first setup, all of the information was being kept in one large database and certain number ranges were set aside for different uses. The number range of 1 through 69,000 was designated as the actual satellite catalog. The range of 70,000 through 79,999 was set aside for the initial element sets used as temporary intermediaries before cataloging as explained earlier. The range 80,000 through 89,999 was set aside for analyst satellites—those objects which are being tracked but cannot be put into the satellite catalog because the launching State hasn’t been determined—and other temporary purposes, such as for burn plans.

Numbers 90,000 through 99,999 were set aside for uncorrelated tracks (UCTs)[2] which are observations gathered by sensors that do not correlate to anything in the catalog.

• Bingo! Jackpot! – uhoh Feb 18 '20 at 21:43
• @uhoh unfortunately, I can't find a source for the 50K's or 60K's being used, but that may have to be chalked up to "I think I heard that once in a hallway..." :) – costrom Feb 18 '20 at 21:44
• Also readable here: Prospects for Improving the Space Catalog – uhoh Feb 18 '20 at 21:45

I can't answer you fully why Celestrak is wrong, but the correct number is 44972. It seems like this was updated in the other source.

New objects are around 45000 right now, they shouldn't be much larger than that.

• Are you certain that Celestrak page was simply "wrong", or is it possible that the 70,000's are used for temporary slots until a lower number can be assigned, a little bit like the way that the 80,000's are used for "Analyst" objects (as discussed in the question)? – uhoh Jan 16 '20 at 14:27
• It's possible, but they are very temporary if that is the case... There are 0 objects in the 70,000 range right now... – PearsonArtPhoto Jan 16 '20 at 16:34
• They're back! See update at bottom of question. I think this is quite intentional and not simply "wrong". i.stack.imgur.com/iRWrA.png – uhoh Jan 30 '20 at 14:26
• newest batch is also starting in the 70,000's i.stack.imgur.com/BX6jm.png This seems to be standard, at least for celestrak.com/NORAD/elements/supplemental/… – uhoh Feb 18 '20 at 12:49

It seems to me that the correct numbers are : NORAD : 44932 & Starlink-1130 as per TLEs from ... the same Celestrak as off today (January 31th)....