A small (initial population in the order of 10k) human colony has been established on an Earth-like planet in a solar system far from their home world. Due to resource limitations, ships traveled round-trip; that is, once colonists and cargo were offloaded on the new planet, they promptly returned to the original world with any desired exports. It is also worth noting that these ships are the only means of communication between the home world and the colony.
After some number of trips, the colony is well-equipped enough to be self-sufficient and permanent, and further shipments are scheduled primarily for trade (luxury goods from the home world, new raw materials from the colony). However, the next ship never arrives. Space travel is difficult, so time estimates require padding to remain realistic, so the colonists patiently wait out whatever may have delayed the ship. After a sufficiently long time, the colonists realize something catastrophic could have befallen this particular ship, but the next one would surely arrive at its designated time, likely bearing news of the first ship's fate. Yet no second ship arrives, nor will one ever again.
The following conditions apply to the marooned colonists:
- Some unknown event has befallen the home world, cutting off travel and communication between the two planets
- Some method of FTL travel was employed by the ships used, thus relatively little time passed before contact was lost (most of the first generation of settlers are still alive at this time)
- No spacefaring vehicles are present on the colony
- Edit for clarity: this planet has a limited but hardy biosphere (none of the flora or fauna have thus far been established, but assume this provides additional resources that can gradually, if crudely replace processed goods and consumables. (see below)
- The colony has the resources and means to survive indefinitely (Edit for clarity: Fresh water is adequately abundant on this planet and water purification systems are among the colony's initial tech. Food in the form of crops and livestock from the home world can likewise be cultivated enough to sustain the current population. Other resources such as medical supplies and clothing are finite, but can be supplemented over time using materials found locally, as mentioned above)
- This planet's environment is hospitable enough that the colonists do not need advanced equipment to survive. The colony, having only existed a short time, lacks the facilities to produce said advanced equipment en masse.
- The colonists, while currently all working together, are informally divided based on profession/vocation
My question pertaining to this setting is how long would it take (in years or generations) would it take before technology regresses to pre-spacefaring levels? Alternatively, will technology degrade even further/not at all?