I finally picked a callsign for my pilot.
As reader Dirk already predicted, I went through the entire list of entries, and then made up my own. However, I got the idea for my pilot’s callsign after reading formerflyer’s very comprehensive comment, so I am declaring him the winner.
You didn’t have all the information—my pilot’s last name is Halley, a name I picked because of its proximity to my protagonist’s last name in alphabetic order. (They needed to be bunk neighbors in Basic, where the bunks were allotted by last name.) I also liked the astronomical relevance, so I have no idea why I didn’t think of her natural callsign of “Comet” earlier. (I rigged a bit of backstory that involves an expedited atmospheric entry right at the outer edges of the safety margin.)
So, formerflyer, you got my synapses on the right track, therefore you get to claim the chunk of Cold War I have ready on my desk for shipment. Just email me your snail-type address at marko dot kloos at gmail dot com, and I’ll get that out to you in the mail.
Thanks for all the participation! I enjoyed the varied entries, especially the ones with creative backstories and explanations.