Burt Rutan was interested in going after it with the Pond Racer, but they didn't get past their test program before one of the engines threw a rod and ended the

Burt Rutan was interested in going after it with the Pond Racer, but they didn't get past their test program before one of the engines threw a rod and ended the project. Apparently the math said it'd have been capable of just barely going supersonic when level.