This puzzle does not actually appear in The Little Book of Semaphores but it is based on one of the puzzles there - the cigarette smoker's problem from section 4.5. Personally, I think cigarettes are gross so we're going to reword things a touch. The idea is the same.
We have four threads in total. One thread, the producer, randomly publishes one of fuel, oxidizer, or astronauts. The remaining three threads are the consumers, or rockets, which must take their resources in the order listed previously. If a rocket doesn't get its resources in that order, it's not safe to prepare the rocket, and if it doesn't have all three, the rocket can't lift-off. Moreover, once all the rockets are prepped, we want to start ...
