Ancient Astronauts and their descendants:

earthquake shortly after they arrive, lss of written materials, paper, supplies - reduced to a survival situation,, all of the science, math, etc. becomes an oral tradition. Most astronauts don't know about rebuilding a society from scratch (if any) might get lucky and have a geologist with some mining experience.

>>48846829
Ann McCaffery's Dragonriders of Pern series. PERN stands for "Parallel Earth, Resources Negligible", a designation given by the initial colonization survey teams.

>>48846829
Issue with the disease thing.

diseases and illnesses are caused by pathogens that have adapted to be infectious to the host animal or plant. The reason why an illness or disease would be lethal is because the illness or disease in question evolved over time to be able to overcome or circumvent our autoimmune response and create symptoms that are harmful to our body but allow for the spread and reproduction of the pathogens.

Any disease or illness inflicted upon a non-native populous will be a result of any pathogens carried over from the planet of origin and surviving the new environment until the native pathogens have had a chance to adapt to the non-native organisms due to initial incompatibility, or get overrun by non-native invasive species of pathogens.

>>48848920
I might have misused the word "disease" in this case. The "deep sleep" is not caused by a pathogen native to the planet.

All colonists are geneticaly modified for the journey. They are enchanced with traits beneficial to the colonisation effort and space travel in general. Several of these new traits were engineered to allow the colonists to enter cryosleep more easily. After many generations, the regulation system is breaking down. These problems cause the "anabiosis mode" to spontaneosly activate and render the person comatose.

In short - the reason for this problem has arrived with the colonists.

>>48848703
Didn't they specifically pick that planet BECAUSE the colonists wanted a planet where they'd be left alone and ignored by the larger society

And didn't they stockpile technological resources specifically so future generations could use them during their planned move from a high-tech to an agrarian society

>>48846829
It's simple Anon.
The colony ship contained people.

The robot supposed to build cities missed their target and built on not-Mars instead, and now await further instruction, but, it's not-Mars and has no atmosphere. And the follow-up ships supposed to contain all the help and tech needed for them to reach back their tech level never came.

>>48852590
This is actually pretty cool, since it can lead to some shenanigans during early astronomical observations of not-Mars.

>>48848146
As a result, the arising society will have solid engineering skills and practices, but close to no theoretical knowledge.

>>48852590
Not OP, but stealing this for alternate future past setting.

File: tomorrows_man_0.jpg (873KB, 1818x2660px)

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The last posthuman astronaut's corpse in a shrine.

http://blog.modernmechanix.com/must-tomorrows-man-look-like-this/

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>>48856692
>atom-powered tricycle dick