Aviation startup Aerion Supersonic is reportedly shutting down operations, ending ambitious plans to bring a supersonic business jet to market later this decade. According to Florida Today, the company has had a hard time funding the productions of its AS2 supersonic plane.

Aerion Supersonic sprung up soon after the Concorde supersonic airliner was retired from service in 2003, unveiling the first iteration of its supersonic business jet design a year later. Ten years after that, it revealed the redesigned AS2 concept with a top speed of Mach 1.4 and a slightly slower but far quieter “Boomless Cruise” autopilot mode, designed to prevent the sonic boom from reaching the ground.

The sudden shutdown comes just two months after the company revealed plans for a 50-passenger commercial airliner capable of traveling faster than speeds of Mach 4. Those fresh ambitions aside, the closure may come as a surprise given the money and resources seemingly at Aerion’s disposal.

Founded by billionaire Robert Bass in 2004, the company went on to attract big name investors and partners in Lockheed Martin and more recently Boeing. It racked up more than US$10 billion in pre-sales of its $120 million AS2 business jet, and was in the midst of constructing a $300 million global headquarters in Melbourne, Florida. In any case, the burden of trying to bring a supersonic business jet to market appears to have overwhelmed the company’s coffers.

“The AS2 supersonic business jet program meets all market, technical, regulatory and sustainability requirements, and the market for a new supersonic segment of general aviation has been validated with $11.2 billion in sales backlog for the AS2,” reads the company statement, as reported by Florida Today. “However, in the current financial environment, it has proven hugely challenging to close on the scheduled and necessary large new capital requirements to finalize the transition of the AS2 into production. Given these conditions, the Aerion Corporation is now taking the appropriate steps in consideration of this ongoing financial environment.”

Sources: Florida Today, CNBC