Mostly the Blueprint drop forecast depends on when the Blueprint was dropped and on which Day of the Month - e.g Sirius Long Repair Droide was dropped on 20.11.2021. You can say that every Blueprint will drop in a intervals of up to 3 or 7 Months. Mostly you can get the Sirius Repair Droide or something else twice in a Year. I expect to see the Sirius Long Repair Droide probably in Febuary or March or April. It's important to keep in mind to look at the other variants 'Long' - 'Strong'
The Sirius Long Repair droide was dropped on 20.11.2021.
Sirius Repair Droide was dropped on 28.11.2021 in the same Month as you see.
The Sirius Strong Repair Droide was dropped on 13.12.2021 in the next Month in the middle.
I think we will see them soon in the next 2 or 4 Months. With a good luck we can seen them in the next Month in the end of Febuary.
I remember to predicted the Sirius Blaster was dropped last year in April i think and it dropped again last year after 5 or 6 Months "Guys this planet has the Sirius Blaster again" and i was right


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fyi: these drops dates counts only for Korell not for any other Servers. also every Server has different Sirius Planets and Names as the Korell or other Servers has.