Japan's New Hypersonic Engine Could Make 2-Hour Flights to the US a Reality | Hacker News

A Hacker News discussion focused on Japan’s hypersonic engine concept for ultra-fast transpacific flights.

The idea could cut Japan–US travel to around two hours, but commercial viability remains uncertain.

Commenters pointed to high costs, heavy fuel burn, and the weak economics that hurt past supersonic aircraft like Concorde.

The most plausible early market may be premium travel, business jets, or private aviation rather than mass commercial service.