I listened to In Search of the Lost Chord this morning and noticed some things.
Throughout almost all of "Departure," there's a slow upwards glissando on what I think is a cello. To some degree, this mirrors the upward motion in the lines "To burst up through tarmac to the sun again / Or to fly to the sun without burning a wing."
I also realized that "To fly to the sun without burning a wing" is a reference to Icarus. In the Greek myth, Daedalus makes wings out of feathers and wax for himself and his son Icarus so they can escape the labyrinth. He warns him not to fly too close to the sea or too close to the sun, but Icarus is so captivated by flying that he ignores this. He does fly too close to the sun, which melts the wax in his wings, and he falls into the sea and drowns.
When I referenced my transcription of the song, I discovered that I'd already noticed this reference to Icarus (in January of last year). It slipped through the cracks when I first set up this project and wrote posts about my old notes.