definitely an alternate history
I don't have time at the moment for details (and won't be near internet till tomorrow at least) - but Australia has a long and distinguished history of innovative inventions and technologies, which then almost never get developed due to lack of political and social interest, and a weak manufacturing infrastructure. This goes back from the present day to the 1950s at least, if not earlier. The history of the Woomera Rocket Range is just one example.
Well, good luck with your novel, and please post bits of it (or whatever) if/when you can ..