Colorado-based Boom Supersonic says it has closed a $100 million Series B investment round to support the development of a Mach-2.2 commercial airliner called Overture.

The funding includes $56 million in new investment as well as $44 million in previously announced investments. Total funding for Boom now stands at more than $141 million. The round was led by Emerson Collective and includes funding from Y Combinator Continuity, Caffeinated Capital, SV Angel and individual investors, Boom said today.

“This new funding allows us to advance work on Overture, the world’s first economically viable supersonic airliner,” Boom founder and CEO Blake Scholl said in a news release. “Overture fares will be similar to today’s business class — widening horizons for tens of millions of travelers. Ultimately, our goal is to make high-speed flight affordable to all.”

Boom says Overture will accommodate the use of next-generation alternative fuels and have a carbon footprint comparable to that of present-day business-class travel. The company is also working on technology aimed at making Overture’s takeoffs and landings as quiet as those of subsonic aircraft.

A one-third-scale prototype called XB-1 is currently being assembled at Boom’s production facility in Centennial, Colo. It’s set to fly later this year with chief test pilot Bill “Doc” Shoemaker at the controls.

Boom says it has more than 100 full-time employees and plans to double that number this year. The company is weighing potential manufacturing sites for Overture, which is scheduled to enter passenger service in the mid-2020s. Future customers include the Virgin Group and Japan Airlines, which have pre-ordered a total of 30 jets between them.

Several other aerospace companies are also targeting supersonic transport. Potential players range from Boeing (which has invested in Reaction Engines) to startups such as Spike Aerospace and Aerion Supersonic (which has teamed up with Lockheed Martin, Airbus and GE Aviation).

Last April, Lockheed Martin Aeronautics won a $247.5 million contract from NASA to develop a prototype super-quiet supersonic jet for the agency’s Low-Boom Flight Demonstrator project. That test aircraft, known as the X-59 QueSST, is due to start flying in late 2022.