Package up a request and payment into an item, stick the item into a rocket, send the rocket off, this produces an item that represents the order is being processed.
You build a landing pad, an assembler that runs for free, and (ideally) animates a powered rocket landing, then yields the items you ordered (and possibly a rocket that needs to be refurbished).
Perhaps it should turn into a partially-complete rocket in a rocket-silo that needs only some rocket parts (to refurbish the rocket) and some fuel to be launched, or perhaps just yield a number of ingredients that can be used to build a new rocket?
