Sheerin entered the Ansari X Prize with plans for a V2 rocket-derived, reusable manned spacecraft dubbed the Canadian Arrow. ARCA – short for Aeronautics and Cosmonautics Romanian Association – also cast its Orizont vehicle in the manned suborbital contest with plans for a reusable rocket engine built from composite materials.

Somehow, I hadn't heard that detail before. Now where was it that I'd heard this idea before...