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:)

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“As well as this because of Oscar’s build and the fact he was already hardwired to operate without power-based memory or logic means that once Oscar had sufficient energy from his solar panels he would power himself on and take his place in history as the world’s one and only zombie satellite.”

AMSAT OSCAR 7: The Little Satellite That Could (28:02 - 28:19)

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