Although a full-scale prototype of the SpaceCub was never built , the design ( and the publicity surrounding the project ) brought public attention to the concept that a small vehicle to fly a private pilot into space might be possible , and in that way served to stimulate the X Prize , which adopted the SpaceCub 's goal of a 100-km flight altitude as a target for a competition . In its way , the SpaceCub vehicle is a predecessor to many of today 's concepts for space tourism
X Prize
Ansari X Prize
SpaceCub