Now, a new company called Leap 71 is moving fast, designing a new aerospike engine and 3D printing it for testing all within a few weeks. The idea is that as atmospheric pressure changes, the bell itself would change as well. On December 18, 2024, the company test fired its oxygen-and-kerosene-burning toroidal aerospike rocket for 11 seconds, recording a 1,110 pounds of thrust. Building a new rocket engine usually takes several years (at least), but Leap 71 claims that their aerospike engine took only a matter of weeks to design, manufacture, and test. “We were able to extend Noyron’s physics to deal with the unique complexity of this engine type,” Leap 71 CEO Josefine Lissner said in a press statement.