TLE Future - Alpha5 or JSON?

the NORAD_CAT_ID satellite number used in the TLE will soon run out of available numbers. Will this platform start using Alpha5 or JSON?

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Not sure what SatNOGS is going to do. Here’s explanation of the issue at Space-Track and Celestrak:

The STK docs read:

The alpha5 format was proposed by the USAF as an intermediary solution for extending the use of TLEs to a larger catalog size. Its use is now discouraged.


The primary key used to identify satellites in SatNOGS is the SatNOGS Satellite ID already, which is not affected by the exhaustion of 5-digit numbers for the NORAD ID.

Exchange of ephemerides like is done via TLEs currently and it is planned already to be extended by the use of CCSDS Orbital Mean-Elements Messages (OMM). I just created satnogs-db#543 to track this.

There is probably no need for Alpha-5 to be used by SatNOGS at any point.


the NORAD ID won’t be running out of numbers for a long time, it was the TLE format that is the problem. it’s legacy is an 80-column IBM computer punch card! And I do believe you get the data via TLE not the more modern GP (General Perturbations, CCSDS) and JSON? that is available.

if the space-track goes away, which is possible Jan 24 where would you get data? I’m researching where Celestrak gets its data, but good guess is that its mostly space-track.

A larger issue is making sure the open-source community has free access to the data. After January 2024, space-track’s public access is decided by the US Secretary of Defense. Currently its law that makes it free, as a result of the Iridium collision in 2009

Hey, do you have any links/info about the January 2024 law? I did a quick search, but just turned up noise.

from what I understand, it will be changing to the civil side of the govt as per Special Policy Directive 3 (SPD3) signed by then Pres. Trump.


US Code Title 10, Section 2274 is the SECDEF responsibilities on Space SSA to/from the outside community.


Another important article about the future of free or fee catalog data