After talking with some colleagues, they told me about the possibility that the Satellite Catalogue Number (SCN) for TLE could be changed from 5 digits to 9 digits. The reason is that the 5-digit format may soon no longer be sufficient to support the growing number of space objects.
So I did some research and came across an article from 2013 showing that this format change is planned for 2019 1. I also came across a Twitter post from March 2020 saying that OneWeb had fun using the 9-digit format for their TLE on Spacetrack 2.
Currently, the official format is still 5 digits. However, if it had to be changed to 9 digits, the modification, certainly trivial to achieve, should be done in Orekit.
As I’m not a big TLE user and I know that there are a lot of people using TLE on this forum , I wonder if you have any information about this possible change of format?