Zombie Satellite (Requirements)

Satellites & Observations
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Well… today (2024-11-13UTC) I was able to receive some signal from UoSAT-2 (OSCAR-11) here in Brazil (See my post on Twitter/X HERE).

With that I came across a big question (It may seem stupid to some. I apologize for that)

Are there “official” requirements for the definition of a zombie satellite??

UoSAT-2 was launched in 1984 but apparently it was not “DEAD” but rather turned off for a period.

Apparently there is a “requirement” which is: The satellite cannot be controlled by its operators.

Does a satellite to be called a zombie satellite necessarily need to be DEAD for a long time or does it only need to be DEAD during the eclipse??

Let’s assume that AO-91 currently has no chance of being controlled by the ground team and is only active under sunlight, can it be considered a zombie satellite??

Again, sorry for the stupid question (I couldn’t find anything on the internet that states anything with any certainty)

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Hi Igor,

“Zombie” satellite sounds funny.
However, I don’t know of any requirements for such a case.

But, what are you actually heading for?
If there were official requirements and UoSat-2 fulfilled them, what would change in the end besides to call the satellite a “zombie”?

To put it simply: What should be the benefit to call a satellite a zombie?

Daniel

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Hello Daniel!!

It definitely wouldn’t have any benefits… I just have this question regarding the name “zombie satellite”

As you can see HERE this Wikipedia post does not mention UoSat-2 (I know Wikipedia is usually not the best place to do research)

I’m trying to receive some of these satellites (it’s cool to hear satellites older than me. UoSat-2, for example, is twice my age :grin:)

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Ah, now it’s clear to me! (:

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I don’t think there is a clear definition while the one in wikipedia article is a fair one.

For me it’s a fuzzy combined version of satellites that are beyond the end of their missions, not able to control them(RF wise) and usually transmitting while they shouldn’t (after a long period of silence for example).

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This is a fascinating discussion. :smile:
It is possible to categorise such satellites into groups.

ZombieSat - one that ‘died’, then ‘revived’ and started incoherent meaningless signal transmission. :grimacing:

RebornSat or PhoenixSat - the one that worked after a long silence. But it worked well, the beacon readable, the system working. :partying_face:

MarasmusSat - the satellite that didn’t go silent. But stopped transmitting correct information, and for a long time transmits a meaningless signal. :face_with_head_bandage:

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I like this idea!!!

I didn’t have much time to research, but it seems that UoSAT-2 didn’t DIE, but rather stopped transmitting for a while (no technical problems with the RF). Please correct me if I’m wrong

UoSAT-2 is still transmitting data as you can see in the photo below (My reception on 2024-11-14UTC). Unfortunately, the signal was weak enough that it couldn’t decode the packets completely.

Screenshot_1
Screenshot_11147×637 258 KB

From the little I’ve researched, UoSAT-2 transmits incorrect information about the time and a few other parameters.

So, maybe UoSAT-2 fits like MarasmusSat

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The satellite is operating in the default mode, controlled by the watchdog timer, with a cycle time of 20.7 days. 10.35 days on followed by 10.35 days off.

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Thanks for the clarification Jan !!!

By the way, does anyone here know of any other old satellite to monitor? (I already received the Transit 5b5 :grin:)