Cargo Cult is the trope when a group of people worship an object as gods or deities. This usually happens either because of its advanced technology, or a ...

Seems like a perfect fit for the Grim Dark?!

Prosaic - no otherworldly power - just a twisted ideology that can lead to fun times in Rogue Trader!

I would imagine one would more than likely by frequency of occurance (i.e. the odds) of finding pretender cults and fake masters (like here on earth lol) - dare I say 8 out of 10 encountered would be lowly and of no paranormal benefit / drawback - like that found in the worship of the Ruinous Powers.

Example - Fallout 3 - the Town of Megaton, worships the Bomb that didn't explode when it rained down... When you do encounter this spectacle your character learns of the dubious nature of the people there and their affection for said ordinance!

Stay GAMING

Morbid

I think it's quite possible. After all, one thing that's quite well established in 40k fiction is the primitive tribe who worship (or at least revere) the sky-warriors, who come from the heavens in their flaming chariots once a generation to choose the finest aspiring warriors...

...Hell, you could argue the entire Adeptus Mechanicus is essentially a well-informed and particularly successful cargo cult.

Any primitive world which has had a previous contact with advanced civilisation might do something similar.

If you want to throw in something to really challenge the players, have it be actively dangerous to them. Imagine, for example - the 'temple' is the control cogitator and fire control for a planetary defence weapon of something appropriately nasty that gets activated during a "ceremony of welcome" for the explorers - a battery of anti-orbit macro-lances, or something. In order to make it out of orbit, the players have to disarm the automata-targeting systems....without being murdered for blasphemy by trying to silence what the priests see as the voice of god.

In my opinion, a "cargo cult" would not even Need to be primitive or be hailing something strange. Nor does it Need to be a blind or slaverish devotion.

It is ingrained in the Imperial society (through the Mechanicus) that machines have a spirit. The People of the Imperium "venerate" those like a (naturalistic) shaman or druid would venerate "nature". They thank when they use it, ask for forgiveness when they broke it, and at some Special days or times, they celebrate it as part of their life or do something else to placate it.

A voidship has some awesome BIG, impressive machines on it. They might not be complex, but they are large, obvious, impressive and the life of bigger parts of a Crew might centre around keeping it function. With the 40k mindset regarding technological items, it is only a far step to venerating them a Little more like an ancestor spirit then a "mere machine spirit". Imagine a weapon deck where the Crew venerate the six macro cannons they tend to, given some attributes to each of them and perhaps hailing another wih a loud, short SHOUTING (in poor mimicry of the sunder of the gun) when doing so in ritual greeting.

Imagine the Crews near the Radiation doors keeping away the ill effect of the fuel that lies behind touching one of those doors shortly before the start of their shift, for protection as These door ARE protection and the spirit of protection themselves.

In short, take our "modern" supestion for greeting our cars, throwing coins into fountains or touching the teat of the statue of Julia (Romeo & Julia) in the City of Verona for "good luck in love", centre it onto something found aboard your ship and take it one step FURTHER.