Iridium Block 1 Constellation Status

Click here for the Block 1 Status Sheet

Here you find the current status of the Iridium Block 1 satellites according to my best knowledge. Recent deorbit and re-entry events are based on current TLEs from and Twitter updates from @IridiumBoss, predicted reentry dates are estimates by SatFlare and

As de-orbits are proceeding rapidly, I check on the satellites daily and update the sheet whenever there is a change. The time stamp of the update is shown on the sheet.

Notes on the Status Sheet: 

  • The blue block “Still flaring” shows the satellites that are still in a stable orbit and can flare reliably.
  • The green block “Tumbling” includes the deorbiting satellites that have already been passivated. They are out of control but on a predictable trajectory, so you might see them tumble.
  • The date format is European: DD.MM.YYYY, time reference is UTC.

Click here for the Block 1 Status Sheet

Last update: 20 March 2019


Some hints for late-stage flare-watching:

Many flare apps do not show you all the flares for the following reasons:

  • Most of them do not show spare, unstable or out-of-service satellites. All of the remaining Block 1 satellites loosely fit into this category, none of them is in service any more.
  • Most apps filter flares according to their magnitude, i.e. perceived brightness. Only a few apps allow for manual adjustment, the others might not show you e.g. a flare with an above-zero magnitude (or whatever criteria they might use).
  • The flare apps are of course not updated by their coders any longer, so some have become unreliable or incompatible or show bugs.

The best and most reliable app for iOS is GoSatWatch. It is quite pricey however and you might not want to invest at this stage. There is a free trial though.
A good source for desktop is CalSky. Its default setting is on “hobby astronomer”. Select “astronomer” in order to get all results and decide yourself which ones are feasible for you.