Re: Starship?
Actually, given an air-breathing rocket such as SABRE, a sub-orbital rocket plane makes a lot of sense. For example:
* The spaceplane takes off horizontally from an airport runway like any other jet airliner. Rocket-powered does not mean vertical-launch, it does not need a launchpad, uh ... okaaay?
* An airbreathing rocket will be no louder than a turbofan with reheat.
* The sonic boom on the outward leg is directed upwards and little if any makes it to ground level.
* The spaceplane spends most of its journey in ballistic spaceflight, burning zero fuel. "Please do not undo your seat belt" though!
* Its engines would only be restarted as a safety precaution in case the landing was aborted at the last minute, so more fuel saved there.