July 21, 2026

Houston, we have a numbering problem

Celestrak adds catalog digit, fixes Y2K bug

Space tracker hit its number limit, and the comments instantly turned into bug roast mode

TLDR: CelesTrak says space object IDs have outgrown the old 5-digit system, so new satellites now need a bigger numbering format and older tools may miss them. Commenters split between “space is getting packed fast,” “this was really fixed years ago,” and one brutal side quest: “please fix the site certificate too.”

The big space-number drama is here: CelesTrak, a popular site people use to track satellites and space junk, says it has officially run out of old 5-digit object numbers. Translation for normal humans: the labeling system was built for a smaller space age, and now there are so many things orbiting Earth that the old setup has finally tapped out. New objects now need 6-digit numbers, and the old text format many hobbyists and tools still rely on won’t work for them anymore. CelesTrak says it actually prepared for this back in 2020 with newer formats that also, yes, finally fixed a Y2K-style date problem.

But the real fireworks were in the reactions. One camp treated this like the satellite version of running out of phone numbers, with one commenter calling it basically IPv4 exhaustion for space, blaming mega-constellations for chewing through the remaining IDs at high speed. Another commenter poked at the headline itself, arguing this isn’t really a “just now” fix because the groundwork was laid years ago, making the timing feel a little clickbaity. And then came the drive-by comedy shot everyone noticed: “Next they should fix their SSL certificate.” Ouch. That one turned a dry infrastructure update into a full-on nerd heckling session.

So yes, this is an important back-end change for space tracking. But in the court of public opinion, the story became a mix of “wow, space is crowded,” “didn’t they already fix this?” and “while you’re at it, fix the website too.” Classic internet.

Key Points

  • CelesTrak said 5-digit catalog numbers were exhausted on 2026-07-11 with the addition of Saramago.
  • The official USSF SATCAT has reached 100100, and new objects will use 6-digit catalog numbers of 100000 or higher.
  • GP data for newly cataloged 6-digit objects will not be available through the legacy TLE format.
  • CelesTrak said it created new formats in May 2020 that remove the 5-digit limitation and fix the Y2K issue.
  • The legacy fixed-field SATCAT will keep updating but only for objects with catalog numbers below 70000.

Hottest takes

"fix their SSL certificate" — VoidWhisperer
"the satellite-tracking version of IPv4 exhaustion" — OymInIRole
"Technically, this is year (2020)" — altairprime
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