Boom Supersonic, backed by Japan Airlines, American Express Ventures, Emerson Collective and others, will begin production of its Overture supersonic aircraft in 2023.

It will seat 65–88 people and begin commercial flights in 2029, founder and CEO Blake Scholl tells Axios.

His goal, he says, is “four hours to anywhere, for $100.” That’s a long way off, but the company aims to start by offering fares comparable to today’s business class.

A handful of other startups, including Hermeus and Spike Aerospace, are also developing supersonic jets.