Bob Koester - 'Companions'

Harry wanted to be alone, and so he was: as alone as a person can be, transmuted into tachyon particles and hurled into deepest space, with nothing but an artificial intelligence for company. He was alone, and then, gradually, he wasn't. Harry and his friend Cailyn, are commanders on distant power stations with nothing but their AIs and their correspondence for company. Harry and Cailyn receive an application that allows them to upload virtual surrogates of themselves so that they can communicate "in-person", and it's the connection forged via those surrogates that might just save the universe.