Not only does the new Space Plane not in anyway promise 4 hour flights from London to Australia but it doesn’t exist even in prototype form. What does exist is a prototype engine that may, if all goes well, be usable for space travel in the 2030’s and could in theory power commercial flights at 5.3 mach speed which would be capable of flying from London to Australia in 4 hours.
Considering the Concorde was banned from flying at Mach speed over land due to the sonic boom i don’t see how this aircraft will over come that obstacle.
I can’t imagine I’d be arsed, especially given how much easier it will be to keep the “Holiday Destinations For The Lone/Accompanied Traveller” threads updated with screenshots of the rock fields of Iceland or perspiring glasses of Moretti by the Med.